@article{jang_deng_sprague_lindsay_2023, title={Divergent Synthesis of & beta;-Fluoroamides via Silver-Catalyzed Oxidative Deconstruction of Cyclopropanone Hemiaminals}, volume={7}, ISSN={["1523-7052"]}, url={https://doi.org/10.1021/acs.orglett.3c01992}, DOI={10.1021/acs.orglett.3c01992}, abstractNote={An expedient approach for the synthesis of challenging β-fluoroamides from readily accessible cyclopropanone equivalents is reported. Following the addition of pyrazole used here as a transient leaving group, silver-catalyzed regiospecific ring-opening fluorination of the resulting hemiaminal leads to a β-fluorinated N-acylpyrazole intermediate reactive to substitution with amines, ultimately affording β-fluoroamides. The process could also be extended to the synthesis of β-fluoroesters and γ-fluoroalcohols via the addition of alcohols or hydrides as terminal nucleophiles, respectively.}, journal={ORGANIC LETTERS}, author={Jang, Yujin and Deng, Weixia and Sprague, Ivan S. S. and Lindsay, Vincent N. G.}, year={2023}, month={Jul} }
 @article{jung_muir_lindsay_2023, title={Expedient synthesis of spiro[3.3]heptan-1-ones via strain-relocating semipinacol rearrangements}, volume={134}, ISSN={["1464-5416"]}, url={https://doi.org/10.1016/j.tet.2023.133296}, DOI={10.1016/j.tet.2023.133296}, abstractNote={A novel approach for the formation of the highly strained spiro[3.3]heptan-1-one motif was developed through the reaction of 1-sulfonylcyclopropanols and lithiated 1-sulfonylbicyclo[1.1.0]butanes. Following initial nucleophilic addition to the cyclopropanone formed in situ, the resulting 1-bicyclobutylcyclopropanol intermediate is prone to a 'strain-relocating' semipinacol rearrangement in the presence of acid, directly affording the substituted spiro[3.3]heptan-1-one. The process is shown to be fully regio- and stereospecific when starting from a substituted cyclopropanone equivalent, leading to optically active 3-substituted spiro[3.3]heptan-1-ones. The reaction likely proceeds via initial protonation of the bicyclobutyl moiety followed by [1,2]-rearrangement of the resulting cyclopropylcarbinyl cation.}, journal={TETRAHEDRON}, publisher={Elsevier BV}, author={Jung, Myunggi and Muir, Joanna E. and Lindsay, Vincent N. G.}, year={2023}, month={Mar} }
 @article{jung_lindsay_2022, title={One-Pot Synthesis of Strain-Release Reagents from Methyl Sulfones br}, volume={144}, ISSN={["1520-5126"]}, url={https://doi.org/10.1021/jacs.2c00923}, DOI={10.1021/jacs.2c00923}, abstractNote={Sulfone-substituted bicyclo[1.1.0]butanes and housanes have found widespread application in organic synthesis due to their bench stability and high reactivity in strain-releasing processes in the presence of nucleophiles or radical species. Despite their increasing utility, their preparation typically requires multiple steps in low overall yield. In this work, we report an expedient and general one-pot procedure for the synthesis of 1-sulfonylbicyclo[1.1.0]butanes from readily available methyl sulfones and inexpensive epichlorohydrin via the dialkylmagnesium-mediated formation of 3-sulfonylcyclobutanol intermediates. Furthermore, the process was extended to the formation of 1-sulfonylbicyclo[2.1.0]pentane (housane) analogues when 4-chloro-1,2-epoxybutane was used as the electrophile instead of epichlorohydrin. Both procedures could be applied on a gram scale with similar efficiency and are shown to be fully stereospecific in the case of housanes when an enantiopure epoxide was employed, leading to a streamlined access to highly valuable optically active strain-release reagents.}, number={11}, journal={JOURNAL OF THE AMERICAN CHEMICAL SOCIETY}, publisher={American Chemical Society (ACS)}, author={Jung, Myunggi and Lindsay, Vincent N. G.}, year={2022}, month={Mar}, pages={4764–4769} }
 @article{rivera_burton_call_tomat_lindsay_2022, title={Synthesis of Highly Congested Tertiary Alcohols via the [3,3] Radical Deconstruction of Breslow Intermediates}, url={https://doi.org/10.26434/chemrxiv-2022-l60sc}, DOI={10.26434/chemrxiv-2022-l60sc}, abstractNote={Pericyclic processes such as [3,3]-sigmatropic rearrangements leading to the rapid generation of molecular complexity constitute highly valuable tools in organic synthesis. Herein, we report the formation of particularly hindered tertiary alcohols via rearrangement of Breslow intermediates formed in situ from readily available N-allyl thiazolium salts and benzaldehyde derivatives. Experimental mechanistic studies performed suggest that the reaction proceeds via a close radical pair which recombine in a regio- and diastereoselective manner, formally leading to [3,3]-rearranged products.}, author={Rivera, Roger Machín and Burton, Nikolas and Call, Luke and Tomat, Marshall and Lindsay, Vincent}, year={2022}, month={May} }
 @article{rivera_burton_call_tomat_lindsay_2022, title={Synthesis of Highly Congested Tertiary Alcohols via the [3,3] Radical Deconstruction of Breslow Intermediates}, volume={24}, ISSN={["1523-7052"]}, url={https://doi.org/10.1021/acs.orglett.2c01627}, DOI={10.1021/acs.orglett.2c01627}, abstractNote={Pericyclic processes such as [3,3]-sigmatropic rearrangements leading to the rapid generation of molecular complexity constitute highly valuable tools in organic synthesis. Herein, we report the formation of particularly hindered tertiary alcohols via rearrangement of Breslow intermediates formed in situ from readily available N-allyl thiazolium salts and benzaldehyde derivatives. Experimental mechanistic studies performed suggest that the reaction proceeds via a close radical pair which recombine in a regio- and diastereoselective manner, formally leading to [3,3]-rearranged products.}, number={23}, journal={ORGANIC LETTERS}, publisher={American Chemical Society (ACS)}, author={Rivera, Roger Machin and Burton, Nikolas R. and Call, Luke D. and Tomat, Marshall A. and Lindsay, Vincent N. G.}, year={2022}, month={Jun}, pages={4275–4280} }
 @article{poteat_lindsay_2021, title={Enantioselective Synthesis of Alkylidenecyclobutanones via Formal Vinylidene Insertion into Cyclopropanone Equivalents}, volume={6}, url={https://doi.org/10.33774/chemrxiv-2021-kv6gx}, DOI={10.33774/chemrxiv-2021-kv6gx}, abstractNote={1-Sulfonylcyclopropanols are employed here as efficient cyclopropanone equivalents in a formal vinylidene insertion process, providing the first general synthetic route to enantioenriched alkylidenecyclobutanones. The addition of an alkenyl-Grignard reagent to the cyclo-propanone leads to an alkenylcyclopropanol capable of electrophilic activation by NBS, triggering a regio- and stereospecific 1,2-migration and the formation of a brominated cyclobutanone intermediate prone to elimination. The parent β-amino ketone can also be accessed by one-pot aza-Michael addition to the resulting product, and activation of the alkenylcyclopropanol intermediate with other electrophiles such as HCl or mCPBA led to the controlled formation of a variety of chiral cyclobutanones and γ-lactones via alternative pathways.}, publisher={Cambridge University Press (CUP)}, author={Poteat, Christopher and Lindsay, Vincent}, year={2021}, month={Jun} }
 @article{poteat_lindsay_2021, title={Enantioselective Synthesis of Alkylidenecyclobutanones via Formal Vinylidene Insertion into Cyclopropanone Equivalents}, volume={6}, url={https://doi.org/10.26434/chemrxiv-2021-kv6gx}, DOI={10.26434/chemrxiv-2021-kv6gx}, abstractNote={1-Sulfonylcyclopropanols are employed here as efficient cyclopropanone equivalents in a formal vinylidene insertion process, providing the first general synthetic route to enantioenriched alkylidenecyclobutanones. The addition of an alkenyl-Grignard reagent to the cyclo-propanone leads to an alkenylcyclopropanol capable of electrophilic activation by NBS, triggering a regio- and stereospecific 1,2-migration and the formation of a brominated cyclobutanone intermediate prone to elimination. The parent β-amino ketone can also be accessed by one-pot aza-Michael addition to the resulting product, and activation of the alkenylcyclopropanol intermediate with other electrophiles such as HCl or mCPBA led to the controlled formation of a variety of chiral cyclobutanones and γ-lactones via alternative pathways.}, publisher={American Chemical Society (ACS)}, author={Poteat, Christopher and Lindsay, Vincent}, year={2021}, month={Jun} }
 @article{penn_anders_lindsay_2021, title={Expedient Synthesis of Bis(imidazolium) Dichloride Salts and Bis(NHC) Complexes from Imidazoles Using DMSO as a Key Polar Additive}, volume={40}, ISSN={["1520-6041"]}, url={https://doi.org/10.1021/acs.organomet.1c00592}, DOI={10.1021/acs.organomet.1c00592}, abstractNote={A general approach for the synthesis of bis(imidazolium) dichloride salts from imidazoles and dichloroalkanes is reported. Typical limitations of this reaction for the formation of methylene-bridged derivatives are addressed herein through the use of excess CH2Cl2 in the presence of DMSO as a polar cosolvent, significantly improving the conversion rates presumably via stabilization of the initial SN2 transition state. The method was also shown to be applicable to the formation of bis(pyridinium) dichloride salts from pyridine derivatives, and to the direct synthesis of metal–bis(NHC) complexes from imidazoles.}, number={23}, journal={ORGANOMETALLICS}, publisher={American Chemical Society (ACS)}, author={Penn, Kyle R. and Anders, Evan J. and Lindsay, Vincent N. G.}, year={2021}, month={Dec}, pages={3871–3875} }
 @article{penn_anders_lindsay_2021, title={Expedient Synthesis of Bis(imidazolium) Dichloride Salts and Bis(NHC) Complexes from Imidazoles using DMSO as a Key Polar Additive}, url={https://doi.org/10.33774/chemrxiv-2021-4h434}, DOI={10.33774/chemrxiv-2021-4h434}, abstractNote={A general approach for the synthesis of bis(imidazolium) dichloride salts from imidazoles and dichloroalkanes is reported. Typical limitations of this reaction for the formation of methylene-bridged derivatives are addressed herein through the use of an excess CH2Cl2 in the presence of DMSO as a polar cosolvent, significantly improving conversion rates presumably via stabilization of the initial SN2 transition state. The method was also shown to be applicable to the formation of bis(pyridinium) dichloride salts from pyridine derivatives, and to the direct synthesis of metal-bis(NHC) complexes from imidazoles.}, author={Penn, Kyle and Anders, Evan and Lindsay, Vincent}, year={2021}, month={Oct} }
 @article{penn_anders_lindsay_2021, title={Expedient Synthesis of Bis(imidazolium) Dichloride Salts and Bis(NHC) Complexes from Imidazoles using DMSO as a Key Polar Additive}, volume={10}, url={https://doi.org/10.26434/chemrxiv-2021-4h434}, DOI={10.26434/chemrxiv-2021-4h434}, abstractNote={A general approach for the synthesis of bis(imidazolium) dichloride salts from imidazoles and dichloroalkanes is reported. Typical limitations of this reaction for the formation of methylene-bridged derivatives are addressed herein through the use of an excess CH2Cl2 in the presence of DMSO as a polar cosolvent, significantly improving conversion rates presumably via stabilization of the initial SN2 transition state. The method was also shown to be applicable to the formation of bis(pyridinium) dichloride salts from pyridine derivatives, and to the direct synthesis of metal-bis(NHC) complexes from imidazoles.}, publisher={American Chemical Society (ACS)}, author={Penn, Kyle and Anders, Evan and Lindsay, Vincent}, year={2021}, month={Oct} }
 @misc{poteat_lindsay_2021, title={Stereospecific Synthesis of Enantioenriched Alkylidenecyclobutanones via Formal Vinylidene Insertion into Cyclopropanone Equivalents}, volume={23}, ISSN={["1523-7052"]}, url={https://doi.org/10.1021/acs.orglett.1c02303}, DOI={10.1021/acs.orglett.1c02303}, abstractNote={1-Sulfonylcyclopropanols are employed here as efficient cyclopropanone equivalents in a formal vinylidene insertion process, providing the first general synthetic route to enantioenriched alkylidenecyclobutanones. The addition of an alkenyl-Grignard reagent leads to an alkenylcyclopropanol capable of electrophilic activation by N-bromosuccinimide, triggering a regio- and stereospecific 1,2-migration and affording alkylidenecyclobutanones after elimination. Activation of the intermediate with other electrophiles such as HCl or mCPBA leads to the formation of various chiral cyclobutanones and γ-lactones via alternative pathways.}, number={16}, journal={ORGANIC LETTERS}, publisher={American Chemical Society (ACS)}, author={Poteat, Christopher M. and Lindsay, Vincent N. G.}, year={2021}, month={Aug}, pages={6482–6487} }
 @article{jang_machin-rivera_lindsay_2021, title={Synthesis and Applications of Cyclopropanones and Their Equivalents as Three-Carbon Building Blocks in Organic Synthesis}, volume={5}, ISSN={["1437-210X"]}, url={https://doi.org/10.1055/a-1519-1670}, DOI={10.1055/a-1519-1670}, abstractNote={Abstract Cyclopropanone derivatives constitute highly strained cycloalkanones with promising applications as three-carbon building blocks in organic synthesis. Due to the presence of a ketone in such a small ring system, all C–C bonds and the carbonyl group are considered to be labile in suitable conditions, leading to a wide variety of synthetic disconnections, including nucleophilic addition, ring expansion, ring-opening, and (formal) cycloaddition. Despite their synthetic potential, the widespread adoption of cyclopropanones as substrates has been considerably hampered by the difficulties associated with the preparation and storage of such unstable compounds, prompting the development of cyclopropanone surrogates that can equilibrate to the parent ketone in situ via elimination. This review summarizes the syntheses and applications of cyclopropanone derivatives and their equivalents, and offers a perspective of the state of the field as well as its expected future directions. 1 Introduction 2 Preparation of Cyclopropanones and Their Equivalents 2.1 Carbenoid Chemistry 2.2 Allene Oxide Rearrangement 2.3 Ring Closure by Dehydrohalogenation or Dehalogenation 2.4 Photolytic Processes 2.5 Miscellaneous Formation of Cyclopropanones 2.6 Cyclopropanone Equivalents 3 Synthetic Applications of Cyclopropanones and Their Equivalents 3.1 Nucleophilic Addition to the Carbonyl Group 3.2 Ring Expansion 3.3 Ring-Opening 3.4 Cycloaddition and Formal Cycloaddition 4 Conclusion and Outlook}, journal={SYNTHESIS-STUTTGART}, publisher={Georg Thieme Verlag KG}, author={Jang, Yujin and Machin-Rivera, Roger and Lindsay, Vincent N. G.}, year={2021}, month={May} }
 @article{poteat_jang_jung_johnson_williams_lindsay_2020, title={Enantioselective Synthesis of Cyclopropanone Equivalents and Application to the Formation of Chiral β-Lactams}, volume={59}, ISSN={["1521-3773"]}, url={https://doi.org/10.1002/anie.202006786}, DOI={10.1002/anie.202006786}, abstractNote={Cyclopropanone derivatives have long been considered unsustainable synthetic intermediates due to their extreme strain and kinetic instability. Herein, we report the enantioselective synthesis of 1-sulfonylcyclopropanols as stable yet powerful equivalents of the corresponding cyclopropanone derivatives, via α-hydroxylation of sulfonylcyclopropanes using a bis(silyl) peroxide as electrophilic oxygen source. This work constitutes the first general approach to enantioenriched cyclopropanone derivatives. Both the electronic and steric nature of the sulfonyl moiety, which serves as a base-labile protecting group and confers crystallinity to these cyclopropanone precursors, were found to have a crucial impact on the rate of equilibration to the corresponding cyclopropanone, highlighting their modular nature and the potential for their widespread adoption as synthetic intermediates. The utility of these cyclopropanone surrogates is demonstrated in a mild and stereospecific formal [3+1] cycloaddition with simple hydroxylamines acting here as nitrene equivalents, leading to the efficient formation of chiral β-lactam derivatives.}, number={42}, journal={Angewandte Chemie International Edition}, publisher={Wiley}, author={Poteat, C.M. and Jang, Y. and Jung, M. and Johnson, J.D. and Williams, R.G. and Lindsay, V.N.G.}, year={2020}, pages={18655–18661} }
 @article{poteat_jang_jung_johnson_williams_lindsay_2020, title={Enantioselective Synthesis of Cyclopropanone Equivalents and Application to the Formation of Chiral β‐Lactams}, volume={132}, url={https://doi.org/10.1002/ange.202006786}, DOI={10.1002/ange.202006786}, abstractNote={Abstract Cyclopropanone derivatives have long been considered unsustainable synthetic intermediates because of their extreme strain and kinetic instability. Reported here is the enantioselective synthesis of 1‐sulfonylcyclopropanols, as stable yet powerful equivalents of the corresponding cyclopropanone derivatives, by α‐hydroxylation of sulfonylcyclopropanes using a bis(silyl) peroxide as the electrophilic oxygen source. This work constitutes the first general approach to enantioenriched cyclopropanone derivatives. Both the electronic and steric nature of the sulfonyl moiety, which serves as a base‐labile protecting group and confers crystallinity to these cyclopropanone precursors, were found to have a crucial impact on the rate of equilibration to the corresponding cyclopropanone. The utility of these cyclopropanone surrogates is demonstrated in a mild and stereospecific formal [3+1] cycloaddition with simple hydroxylamines, leading to the efficient formation of chiral β‐lactam derivatives.}, number={42}, journal={Angewandte Chemie}, publisher={Wiley}, author={Poteat, Christopher M. and Jang, Yujin and Jung, Myunggi and Johnson, J. Drake and Williams, Rachel G. and Lindsay, Vincent N. G.}, year={2020}, month={Oct}, pages={18814–18820} }
 @article{rivera_jang_poteat_lindsay_2020, title={General Synthesis of Cyclopropanols via Organometallic Addition to 1-Sulfonylcyclopropanols as Cyclopropanone Precursors}, volume={22}, ISSN={1523-7060 1523-7052}, url={http://dx.doi.org/10.1021/acs.orglett.0c02303}, DOI={10.1021/acs.orglett.0c02303}, abstractNote={The addition of organometallic reagents to ketones constitutes one of the most straightforward synthetic approaches to tertiary alcohols. However, due to the absence of a well-behaved class of cyclopropanone surrogates accessible in enantioenriched form, such a trivial synthetic disconnection has received very little attention in the literature for the formation of tertiary cyclopropanols. In this work, we report a simple and high-yielding synthesis of 1-substituted cyclopropanols via the addition of diverse organometallic reagents to 1-phenylsulfonylcyclopropanols, acting here as in situ precursors of the corresponding cyclopropanones. The transformation is shown to be amenable to sp-, sp2-, or sp3-hybridized organometallic C-nucleophiles under mild conditions, and the use of enantioenriched substrates led to highly diastereoselective additions and the formation of optically active cyclopropanols.}, number={16}, journal={Organic Letters}, publisher={American Chemical Society (ACS)}, author={Rivera, Roger Machín and Jang, Yujin and Poteat, Christopher M. and Lindsay, Vincent N. G.}, year={2020}, month={Aug}, pages={6510–6515} }
 @article{rivera_jang_poteat_lindsay_2020, title={General Synthesis of Cyclopropanols via Organometallic Addition to 1-Sulfonylcyclopropanols as Cyclopropanone Precursors}, url={https://doi.org/10.26434/chemrxiv.12644153}, DOI={10.26434/chemrxiv.12644153}, abstractNote={The addition of organometallic reagents to ketones constitutes one of the most straightforward synthetic approaches to tertiary alcohols. However, due to the absence of a well-behaved class of cyclopropanone surrogates accessible in enantioenriched form, such a trivial synthetic disconnection has received very little attention in the literature for the formation of tertiary cyclopropanols. In this work, we report a simple and high-yielding synthesis of 1-substituted cyclopropanols via the addition of diverse organometallic reagents to 1-phenylsulfonylcyclopropanols, acting here as in situ precursors of the corresponding cyclopropanones. The transformation is shown to be amenable to sp-, sp2-, or sp3-hybridized organometallic C-nucleophiles under mild conditions, and the use of enantioenriched substrates led to highly diastereoselective additions and the formation of optically active cyclopropanols.}, author={Rivera, Roger Machín and Jang, Yujin and Poteat, Christopher M. and Lindsay, Vincent}, year={2020}, month={Jul} }
 @article{rivera_jang_poteat_lindsay_2020, title={General Synthesis of Cyclopropanols via Organometallic Addition to 1-Sulfonylcyclopropanols as Cyclopropanone Precursors}, volume={7}, url={https://doi.org/10.26434/chemrxiv.12644153.v1}, DOI={10.26434/chemrxiv.12644153.v1}, abstractNote={The addition of organometallic reagents to ketones constitutes one of the most straightforward synthetic approaches to tertiary alcohols. However, due to the absence of a well-behaved class of cyclopropanone surrogates accessible in enantioenriched form, such a trivial synthetic disconnection has only received very little attention in the literature for the formation of tertiary cyclopropanols. In this work, we report a simple and high-yielding synthesis 1-substituted cyclopropanols via the addition of diverse organometallic reagents to 1- phenylsulfonylcyclopropanols, acting here as in situ precursors of the corresponding cyclopropanones.The transformation is shown to be amenable to sp, sp2 or sp3 -hybridized organometallic C-nucleophiles under mild conditions, and the use of enantioenriched substrates led to highly diastereoselective additions and the formation of optically active cyclopropanols.}, publisher={American Chemical Society (ACS)}, author={Rivera, Roger Machín and Jang, Yujin and Poteat, Christopher M. and Lindsay, Vincent}, year={2020}, month={Jul} }
 @article{jang_lindsay_2020, title={Synthesis of Cyclopentenones with Reverse Pauson-Khand Regiocontrol via Ni-Catalyzed C–C Activation of Cyclopropanone}, volume={9}, url={https://doi.org/10.26434/chemrxiv.13012895}, DOI={10.26434/chemrxiv.13012895}, abstractNote={A formal [3+2] cycloaddition between cyclopropanone and alkynes via Ni-catalyzed C–C bond activation has been developed, where 1-sulfonylcyclopropanols are employed as key precursors of cyclopropanone in the presence of trimethylaluminum. The transformation provides access to 2,3-disubstituted cyclopentenones with complete regiocontrol, favoring reverse Pauson-Khand products where the large substituent is located at the 3-position of the ring. In the process, the trimethylaluminum additive is thought to play multiple roles, including as a Brønsted base triggering the equilibration to cyclopropanone and liberation of methane, as well as a source of Lewis acid to activate the carbonyl group toward Ni-catalyzed C–C activation.}, publisher={American Chemical Society (ACS)}, author={Jang, Yujin and Lindsay, Vincent}, year={2020}, month={Sep} }
 @article{jang_lindsay_2020, title={Synthesis of Cyclopentenones with Reverse Pauson-Khand Regiocontrol via Ni-Catalyzed C–C Activation of Cyclopropanone}, volume={9}, url={https://doi.org/10.26434/chemrxiv.13012895.v1}, DOI={10.26434/chemrxiv.13012895.v1}, abstractNote={A formal [3 + 2] cycloaddition between cyclopropanone and alkynes via Ni-catalyzed C-C bond activation has been developed, where 1-sulfonylcyclopropanols are employed as key precursors of cyclopropanone in the presence of trimethylaluminum. The transformation provides access to 2,3-disubstituted cyclopentenones with complete regiocontrol, favoring reverse Pauson-Khand products, where the large substituent is located at the 3-position of the ring. In the process, the trimethylaluminum additive is thought to play multiple roles, including as a Brønsted base triggering the equilibration to cyclopropanone and liberation of methane, as well as a source of Lewis acid to activate the carbonyl group toward Ni-catalyzed C-C activation.}, publisher={American Chemical Society (ACS)}, author={Jang, Yujin and Lindsay, Vincent}, year={2020}, month={Sep} }
 @article{jang_lindsay_2020, title={Synthesis of Cyclopentenones with Reverse Pauson–Khand Regiocontrol via Ni-Catalyzed C–C Activation of Cyclopropanone}, volume={22}, url={https://doi.org/10.1021/acs.orglett.0c03246}, DOI={10.1021/acs.orglett.0c03246}, abstractNote={A formal [3 + 2] cycloaddition between cyclopropanone and alkynes via Ni-catalyzed C–C bond activation has been developed, where 1-sulfonylcyclopropanols are employed as key precursors of cyclopropanone in the presence of trimethylaluminum. The transformation provides access to 2,3-disubstituted cyclopentenones with complete regiocontrol, favoring reverse Pauson–Khand products, where the large substituent is located at the 3-position of the ring. In the process, the trimethylaluminum additive is thought to play multiple roles, including as a Brønsted base triggering the equilibration to cyclopropanone and liberation of methane, as well as a source of Lewis acid to activate the carbonyl group toward Ni-catalyzed C–C activation.}, number={22}, journal={Organic Letters}, publisher={American Chemical Society (ACS)}, author={Jang, Yujin and Lindsay, Vincent N. G.}, year={2020}, month={Nov}, pages={8872–8876} }
 @article{zhu_lindsay_2019, title={Benzimidazolyl Palladium Complexes as Highly Active and General Bifunctional Catalysts in Sustainable Cross-Coupling Reactions}, volume={9}, ISSN={["2155-5435"]}, url={https://doi.org/10.1021/acscatal.9b02420}, DOI={10.1021/acscatal.9b02420}, abstractNote={A family of air- and moisture-stable dinuclear palladium complexes bearing 2-benzimidazolyl ligands is reported and shown to be a highly effective and general catalytic platform in diverse cross-coupling reactions. The rigidity and conformation of the ligand scaffold was readily modified via tethering of the 2-benzimidazolyl moiety to diamine ligands, resulting in significant changes in catalytic activity. Under optimal conditions, Suzuki, Heck, and Sonogashira-type couplings of aryl bromides can all be performed efficiently with good functional group compatibility using only 0.1 mol % of catalyst, in aqueous or alcohol solvents. Experimental evidence highlights the importance of the bifunctional character of the ligand for catalytic activity, where the basic N-functionality in the ligand framework is proposed to accelerate (trans)metalation steps via intramolecular assistance.}, number={8}, journal={ACS CATALYSIS}, publisher={American Chemical Society (ACS)}, author={Zhu, Jiancheng and Lindsay, Vincent N. G.}, year={2019}, month={Aug}, pages={6993–6998} }
 @article{poteat_lindsay_2019, title={Controlled -mono- and ,-di-halogenation of alkyl sulfones using reagent-solvent halogen bonding}, volume={55}, ISSN={["1364-548X"]}, url={https://doi.org/10.1039/C9CC00550A}, DOI={10.1039/c9cc00550a}, abstractNote={The direct and selective α-mono-bromination of alkyl sulfones was achieved through base-mediated electrophilic halogenation. The appropriate combination of solvent and electrophilic bromine source was found to be critical to control the nature of the products formed, where reagent-solvent halogen bonding is proposed to control the selectivity via alteration of the effective size of the electrophilic bromine source. Conversely, the α,α-di-brominated sulfones were selectively obtained in good yields following polyhalogenation followed by selective de-halogenation during workup. Both procedures can be applied on gram scale, and the mono-halogenation was successfully extended to the fully selective α-chlorination, α-iodination and α-fluorination of alkyl sulfones.}, number={20}, journal={CHEMICAL COMMUNICATIONS}, publisher={Royal Society of Chemistry (RSC)}, author={Poteat, Christopher M. and Lindsay, Vincent N. G.}, year={2019}, month={Mar}, pages={2912–2915} }
 @article{poteat_jang_jung_johnson_williams_lindsay_2019, title={Enantioselective Synthesis of Cyclopropanone Equivalents and Application to the Synthesis of β-Lactams}, url={https://doi.org/10.26434/chemrxiv.11457909}, DOI={10.26434/chemrxiv.11457909}, abstractNote={Cyclopropanone derivatives have long been considered unsustainable synthetic intermediates due to their extreme strain and kinetic instability. Herein, we report the enantioselective synthesis of 1-sulfonylcyclopropanols as stable yet powerful equivalents of the corresponding cyclopropanone derivatives, via α-hydroxylation of sulfonylcyclopropanes using a bis(silyl) peroxide as electrophilic oxygen source. Both the electronic and steric nature of the sulfonyl moiety, which serves as a base-labile protecting group and confers crystallinity to these cyclopropanone precursors, were found to have a crucial impact on the rate of equilibration to the corresponding cyclopropanone, highlighting the modular nature of these precursors and the potential for their widespread adoption as synthetic intermediates. The utility of these cyclopropanone surrogates is demonstrated in a mild and stereospecific formal [3+1] cycloaddition with simple hydroxylamines acting here as nitrene equivalents, leading to the efficient formation of chiral β-lactam derivatives.}, author={Poteat, Christopher M. and Jang, Yujin and Jung, Myunggi and Johnson, John D. and Williams, Rachel G. and Lindsay, Vincent}, year={2019}, month={Dec} }
 @article{poteat_jang_jung_johnson_williams_lindsay_2019, title={Enantioselective Synthesis of Cyclopropanone Equivalents and Application to the Synthesis of β-Lactams}, volume={12}, url={https://doi.org/10.26434/chemrxiv.11457909.v1}, DOI={10.26434/chemrxiv.11457909.v1}, abstractNote={Cyclopropanone derivatives have long been considered unsustainable synthetic intermediates due to their extreme strain and kinetic instability. Herein, we report the enantioselective synthesis of 1-sulfonylcyclopropanols as stable yet powerful equivalents of the corresponding cyclopropanone derivatives, via α-hydroxylation of sulfonylcyclopropanes using a bis(silyl) peroxide as electrophilic oxygen source. Both the electronic and steric nature of the sulfonyl moiety, which serves as a base-labile protecting group and confers crystallinity to these cyclopropanone precursors, were found to have a crucial impact on the rate of equilibration to the corresponding cyclopropanone, highlighting the modular nature of these precursors and the potential for their widespread adoption as synthetic intermediates. The utility of these cyclopropanone surrogates is demonstrated in a mild and stereospecific formal [3+1] cycloaddition with simple hydroxylamines acting here as nitrene equivalents, leading to the efficient formation of chiral β-lactam derivatives.}, publisher={American Chemical Society (ACS)}, author={Poteat, Christopher M. and Jang, Yujin and Jung, Myunggi and Johnson, John D. and Williams, Rachel G. and Lindsay, Vincent}, year={2019}, month={Dec} }
 @inbook{rhodium(ii)-catalyzed cyclopropanation_2018, url={https://www.wiley.com/en-us/Rhodium+Catalysis+in+Organic+Synthesis%3A+Methods+and+Reactions-p-9783527811892}, booktitle={Rhodium Catalysis in Organic Synthesis: Methods and Reactions}, year={2018}, month={Dec} }
 @inbook{lindsay_2017, place={Hoboken, New Jersey}, title={Dirhodium(II) Tetrakis[R-2-oxaazetidine-4(S)-carboxylate]}, ISBN={9780470842898}, booktitle={Encyclopedia of Reagents for Organic Synthesis}, publisher={John Wiley & Sons Ltd}, author={Lindsay, V.N.G.}, editor={Charette, A.B. and Crich, D. and Fuchs, P.L. and Molander, G.A.Editors}, year={2017} }
 @article{lindsay_murphy_sarpong_2017, title={Effect of protic additives in Cu-catalysed asymmetric Diels-Alder cycloadditions of doubly activated dienophiles: towards the synthesis of magellanine-type Lycopodium alkaloids}, volume={53}, ISSN={["1364-548X"]}, url={http://dx.doi.org/10.1039/c7cc06367a}, DOI={10.1039/c7cc06367a}, abstractNote={The pronounced beneficial effect of a precise amount of protic additive in an enantioselective Cu-catalysed Diels-Alder reaction is reported. This reaction, which employs a cyclic alkylidene β-ketoester as a dienophile, represents one of the first examples of a transformation where these extremely versatile, though highly unstable reaction partners participate effectively in catalytic asymmetric cycloaddition with a functionalised diene. The cycloadduct was used as an intermediate towards the synthesis of magellanine-type Lycopodium alkaloids featuring a Stille cross-coupling of a highly congested enol triflate and a unique Meinwald rearrangement/cyclopropanation sequence.}, number={74}, journal={CHEMICAL COMMUNICATIONS}, author={Lindsay, Vincent N. G. and Murphy, Rebecca A. and Sarpong, Richmond}, year={2017}, month={Sep}, pages={10291–10294} }
 @article{lindsay_viart_sarpong_2015, title={Stereodivergent Intramolecular C(sp3)–H Functionalization of Azavinyl Carbenes: Synthesis of Saturated Heterocycles and FusedN-Heterotricycles}, volume={137}, ISSN={0002-7863 1520-5126}, url={http://dx.doi.org/10.1021/JACS.5B04295}, DOI={10.1021/jacs.5b04295}, abstractNote={A general approach for the formation of five-membered saturated heterocycles by intramolecular C(sp(3))-H functionalization is reported. Using N-sulfonyltriazoles as Rh(II) azavinyl carbene equivalents, a wide variety of stereodefined cis-2,3-disubstituted tetrahydrofurans were obtained with good to excellent diastereoselectivity from readily available acyclic precursors. The reaction is shown to be amenable to gram scale, and judicious choice of reaction conditions allowed for stereodivergence, providing selective access to the trans diastereomer in good yield. The resulting products were shown to be valuable intermediates for the direct preparation of fused N-heterotricycles in one step by intramolecular C-H amination or Pictet-Spengler cyclization.}, number={26}, journal={Journal of the American Chemical Society}, publisher={American Chemical Society (ACS)}, author={Lindsay, Vincent N. G. and Viart, Hélène M.-F. and Sarpong, Richmond}, year={2015}, month={Jun}, pages={8368–8371} }
 @article{johnson_de rond_lindsay_keasling_sarpong_2015, title={Synthesis of Cycloprodigiosin Identifies the Natural Isolate as a Scalemic Mixture}, volume={17}, ISSN={1523-7060 1523-7052}, url={http://dx.doi.org/10.1021/ACS.ORGLETT.5B01527}, DOI={10.1021/ACS.ORGLETT.5B01527}, abstractNote={The enantiomers of the natural product cycloprodigiosin were prepared using an expedient five-step synthetic sequence that takes advantage of a Schöllkopf–Barton–Zard (SBZ) pyrrole annulation with a chiral isocyanoacetate and a nitrocyclohexene derivative. Using chiral HPLC and X-ray crystallographic analyses of the synthetically prepared material and natural isolate (isolated from the marine bacterium Pseudoalteromonas rubra), naturally occurring cycloprodigiosin was determined to be a scalemic mixture occurring in an enantiomeric ratio of 83:17 (R)/(S) at C4′.}, number={14}, journal={Organic Letters}, publisher={American Chemical Society (ACS)}, author={Johnson, Rebecca E. and de Rond, Tristan and Lindsay, Vincent N. G. and Keasling, Jay D. and Sarpong, Richmond}, year={2015}, month={Jun}, pages={3474–3477} }
 @inbook{1.11 nucleophilic addition of nonstabilized carbanions to imines and imine derivatives_2014, url={http://dx.doi.org/10.1016/b978-0-08-097742-3.00114-2}, DOI={10.1016/b978-0-08-097742-3.00114-2}, abstractNote={This chapter summarizes various state-of-the-art methods to generate α-chiral amines by the nucleophilic addition of nonstabilized carbanions to imine derivatives. The first part of the chapter focuses on methods in which chiral imines react with nucleophiles to generate diastereomeric amines. The relative diastereocontrol is usually excellent when suitable conditions are selected. This section also includes a discussion of chiral auxiliary-based methods. The last section of the chapter describes the most effective asymmetric catalytic methods to achieve this transformation. Each section highlights the best methods available depending on the nature of carbanion used (sp3 vs. sp2 vs. sp carbanion).}, booktitle={Comprehensive Organic Synthesis II}, year={2014} }
 @article{schultz_lindsay_sarpong_2014, title={Expedient Synthesis of Fused Azepine Derivatives Using a Sequential Rhodium(II)-Catalyzed Cyclopropanation/1-Aza-Cope Rearrangement of Dienyltriazoles}, volume={53}, ISSN={1433-7851}, url={http://dx.doi.org/10.1002/ANIE.201405356}, DOI={10.1002/ANIE.201405356}, abstractNote={A general method for the formation of fused dihydroazepine derivatives from 1-sulfonyl-1,2,3-triazoles bearing a tethered diene is reported. The process involves an intramolecular cyclopropanation of an α-imino rhodium(II) carbenoid, leading to a transient 1-imino-2-vinylcyclopropane intermediate which rapidly undergoes a 1-aza-Cope rearrangement to generate fused dihydroazepine derivatives in moderate to excellent yields. The reaction proceeds with similar efficiency on gram scale. The use of catalyst-free conditions leads to the formation of a novel [4.4.0] bicyclic heterocycle.}, number={37}, journal={Angewandte Chemie International Edition}, publisher={Wiley}, author={Schultz, Erica E. and Lindsay, Vincent N. G. and Sarpong, Richmond}, year={2014}, month={Jul}, pages={9904–9908} }
 @misc{2-diazo-1-(4-methoxyphenyl)-2-nitroethanone_2013, url={http://dx.doi.org/10.1002/047084289x.rn01542}, DOI={10.1002/047084289x.rn01542}, abstractNote={[1196665-69-6] C9H7N3O4 (MW 221.17) 
 
InChI = 1S/C9H7N3O4/c1-16-7-4-2-6(3-5-7)8(13)9(11-10)12(14)15/h2-5H,1H3 
 
InChIKey = WOIHPWWKNSZJKD-UHFFFAOYSA-N 
 
 
 
 
 
(used as a carbene precursor for Rh(II)-catalyzed cyclopropanation of alkenes, leading to the corresponding α-nitro-cyclopropylketones) 
 
 
 
Alternative Name: none. 
 
 
 
Physical Data: mp 75–76 °C, yellow solid. 
 
 
 
Solubility: soluble in CH2Cl2, CHCl3, THF, DMF, and MeCN. Slightly soluble in Et2O. Insoluble in H2O. 
 
 
 
Form Supplied in: not commercially available. 
 
 
 
Purification: silica gel chromatography, using 100% CHCl3 as eluent. 
 
 
 
Handling, Storage, and Precautions: explosive compound (shock and heat sensitive). The title compound should be stored neat at −20 °C, at which it is stable for at least 12 months. It can be stored at room temperature for 1 d without decomposition.}, journal={Encyclopedia of Reagents for Organic Synthesis}, year={2013}, month={Apr} }
 @misc{methyl α-diazo-4-methoxy-β-oxo-benzenepropanoate_2013, url={http://dx.doi.org/10.1002/047084289x.rn01540}, DOI={10.1002/047084289x.rn01540}, abstractNote={[1198573-66-8] C11H10N2O4 (MW 234.21) 
 
InChI = 1S/C11H10N2O4/c1-16-8-5-3-7(4-6-8)10(14)9(13-12)11(15)17-2/h3-6H,1-2H3 
 
InChIKey = VNNIUPQLCJJRGZ-UHFFFAOYSA-N 
 
 
 
 
 
(used as a carbene precursor for Rh(II)-catalyzed cyclopropanation of alkenes to form β-keto-cyclopropanecarboxylates, and for the formation of 2-aminofurans via a carbenoid-mediated formal [3+2] cycloaddition with enamines) 
 
 
 
Alternative Name: none. 
 
 
 
Physical Data: yellow oil. 
 
 
 
Solubility: soluble in most organic solvents. 
 
 
 
Form Supplied in: not commercially available. 
 
 
 
Purification: silica gel chromatography, using 25% EtOAc in hexane as eluent. 
 
 
 
Handling, Storage, and Precautions: potentially explosive compound. The title compound should be stored neat at −20 °C, at which temperature it is stable for at least 12 months.}, journal={Encyclopedia of Reagents for Organic Synthesis}, year={2013}, month={Apr} }
 @inbook{stereoselective formation of amines by nucleophilic addition to azomethine derivatives_2013, url={http://dx.doi.org/10.1007/128_2013_492}, DOI={10.1007/128_2013_492}, abstractNote={This chapter describes state-of-the-art methods to prepare α-chiral amines by the addition of nonstabilized nucleophiles to imine derivatives. The first part of the chapter illustrates the most effective diastereoselective addition reaction (substrate controlled and chiral auxiliary based methods) whereas the second part focuses on catalytic asymmetric methods.}, booktitle={Stereoselective Formation of Amines}, year={2013} }
 @article{lindsay_fiset_gritsch_azzi_charette_2013, title={Stereoselective Rh2 (S-IBAZ) 4-Catalyzed Cyclopropanation of Alkenes, Alkynes, and Allenes: Asymmetric Synthesis of Diacceptor Cyclopropylphosphonates and Alkylidenecyclopropanes}, volume={135}, ISSN={0002-7863 1520-5126}, url={http://dx.doi.org/10.1021/ja3099728}, DOI={10.1021/ja3099728}, abstractNote={A mild and highly stereoselective rhodium(II)-catalyzed cyclopropanation of alkenes, alkynes, and allenes with diacceptor diazo compounds is reported. Using the phosphonate moiety as an efficient trans-directing group, the first catalytic asymmetric route to diacceptor cycloprop(en)ylphosphonates was developed by employing an α-cyano diazophosphonate and Rh(2)(S-IBAZ)(4) as chiral catalyst. The isosteric character of phosphonic and carboxylic acid derivatives allowed the alternative use of an α-cyano diazo ester in the process, leading to α-cyano cycloprop(en)ylcarboxylates in high yields and stereoselectivities. Taking advantage of the particular reactivity of the cyanocarbene intermediates involved in this system, the scope of compatible substrates could be extended to substituted allenes, leading to the development of the first catalytic enantioselective method for the synthesis of diacceptor alkylidenecyclopropanes.}, number={4}, journal={Journal of the American Chemical Society}, publisher={American Chemical Society (ACS)}, author={Lindsay, Vincent N. G. and Fiset, Dominic and Gritsch, Philipp J. and Azzi, Soula and Charette, André B.}, year={2013}, month={Jan}, pages={1463–1470} }
 @misc{α-diazo-4-methoxy-β-oxobenzenepropanenitrile_2013, url={http://dx.doi.org/10.1002/047084289x.rn01541}, DOI={10.1002/047084289x.rn01541}, abstractNote={[126893-72-9] C10H7N3O2 (MW 201.18) 
 
InChI = 1S/C10H7N3O2/c1-15-8-4-2-7(3-5-8)10(14)9(6-11)13-12/h2-5H,1H3 
 
InChIKey = SSRJRWKNAOEFFT-UHFFFAOYSA-N 
 
 
 
 
 
(used as a carbene precursor for Rh(II)-catalyzed cyclopropanation of alkenes to form α-cyano-cyclopropylketones, and for the formation of 5-halo-1,2,3-triazoles) 
 
 
 
Alternative Name: none. 
 
 
 
Physical Data: mp 62 °C, yellow solid. 
 
 
 
Solubility: soluble in CH2Cl2, CHCl3, THF, DMF, MeCN. Slightly soluble in Et2O. 
 
 
 
Form Supplied in: not commercially available. 
 
 
 
Purification: silica gel chromatography, using 80% CHCl3 in hexane as eluent. 
 
 
 
Handling, Storage, and Precautions: the compound is potentially explosive and should be stored neat at −20 °C, at which it is stable for at least 12 months.}, journal={Encyclopedia of Reagents for Organic Synthesis}, year={2013}, month={Apr} }
 @misc{1-nitropropane_2012, url={http://dx.doi.org/10.1002/047084289x.rn051.pub2}, DOI={10.1002/047084289x.rn051.pub2}, abstractNote={[108-03-2] C3H7NO2 (MW 89.11) InChI = 1S/C3H7NO2/c1-2-3-4(5)6/h2-3H2,1H3 InChIKey = JSZOAYXJRCEYSX-UHFFFAOYSA-N (for aromatic aldehyde to nitrile conversion;2 nitronate, as acyl anion equivalent of n-propanal, as a n-propyl anion equivalent, reaction with electrophiles3) Physical Data: mp −104 °C; bp 131 °C; d 1.001 g cm−3. Solubility: 1.5 g wt % in H2O at 25 °C; sol ethanol, ether. Form Supplied in: liquid, widely available. Drying: use calcium chloride, calcium sulfate, magnesium sulfate. Handling, Storage, and Precautions: flammable; avoid contact with bases; toxic; dry nitronate salts can be explosive; 1-nitropropane (pKa = 8.98) can be deprotonated by bases such as NaOH, TEA, DBU, TMG, NaH, or LDA. The resulting 1-nitropropane nitronate is the usual reactive form of the reagent.}, journal={Encyclopedia of Reagents for Organic Synthesis}, year={2012}, month={Sep} }
 @misc{2-azido-1,3-dimethylimidazolinium chloride_2012, url={http://dx.doi.org/10.1002/047084289x.rn01465}, DOI={10.1002/047084289x.rn01465}, abstractNote={[1205534-16-2] C5H10ClN5 (MW 175.62) 
 
InChI = 1S/C5H10N5.ClH/c1-9-3-4-10(2)5(9)7-8-6;/h3-4H2,1-2H3;1H/q+1;/p-1 
 
InChIKey = YBTZVYAMDIRLBH-UHFFFAOYSA-M 
 
 
 
 
 
(used as a diazo transfer reagent for 1,3-dicarbonyl compounds and naphthols, and for the formation of azides from anilines or carboxylic acids) 
 
 
 
Alternative Name: ADMC. 
 
 
 
Physical Data: not isolated. 
 
 
 
Solubility: soluble in MeCN. 
 
 
 
Form Supplied in: not isolated. 
 
 
 
Purification:not isolated. 
 
 
 
Handling, Storage, and Precautions: potentially explosive. Highly hygroscopic. Formed in situ from the reaction between sodium azide and 2-chloro 1,3-dimethylimidazolinium chloride in MeCN.}, journal={Encyclopedia of Reagents for Organic Synthesis}, year={2012}, month={Sep} }
 @article{moreau_alberico_lindsay_charette_2012, title={Catalytic asymmetric synthesis of nitrocyclopropane carboxylates}, volume={68}, ISSN={0040-4020}, url={http://dx.doi.org/10.1016/j.tet.2011.05.113}, DOI={10.1016/j.tet.2011.05.113}, abstractNote={A Cu(I)-catalyzed asymmetric cyclopropanation of alkenes with an iodonium ylide has been developed. The copper source, hypervalent iodine source, solvent, and additives all have a significant effect on the yields and enantioselectivities. High enantioselectivity (up to 99:1 er) and diastereoselectivity (95:5 dr trans/cis) were achieved for a wide range of alkenes. Conditions were developed to convert the trans products to the cis isomers. In addition, 1-nitrocyclopropyl carboxylates were transformed into the corresponding substituted cyclopropane amino acids and aminocyclopropanes. Moreover, a comparative study between Zn- and In-mediated reduction reactions of the nitro group in these compounds with regards to the er erosion in the process is also documented.}, number={17}, journal={Tetrahedron}, publisher={Elsevier BV}, author={Moreau, Benoît and Alberico, Dino and Lindsay, Vincent N.G. and Charette, André B.}, year={2012}, month={Apr}, pages={3487–3496} }
 @article{lindsay_charette_2012, title={Design and Synthesis of Chiral Heteroleptic Rhodium(II) Carboxylate Catalysts: Experimental Investigation of Halogen Bond Rigidification Effects in Asymmetric Cyclopropanation}, volume={2}, ISSN={2155-5435 2155-5435}, url={http://dx.doi.org/10.1021/cs300214v}, DOI={10.1021/cs300214v}, abstractNote={A general method for the synthesis of chiral heteroleptic rhodium(II) tetracarboxylate catalysts is reported. The chlorinated TCPT unit was found to be an efficient polarity-control group, allowing the isolation of each complex from a mixture of six possible products. This approach contributes to enlarging the scope of accessible chiral Rh(II) catalysts and allowed further study of the halogen bond rigidification effect observed in chlorinated complexes.}, number={6}, journal={ACS Catalysis}, publisher={American Chemical Society (ACS)}, author={Lindsay, Vincent N. G. and Charette, André B.}, year={2012}, month={May}, pages={1221–1225} }
 @misc{nitromethane_2012, url={http://dx.doi.org/10.1002/047084289x.rn041.pub2}, DOI={10.1002/047084289x.rn041.pub2}, abstractNote={[75-52-5] CH3NO2 (MW 61.05) InChI = 1S/CH3NO2/c1-2(3)4/h1H3 InChIKey = LYGJENNIWJXYER-UHFFFAOYSA-N (building block in synthesis; polar solvent) Physical Data: mp −28.5 °C; bp 101 °C; d 1.13 g cm−3; dipole moment 3.5 D. Solubility: completely misc most organic solvents; slightly sol petroleum ether, water; sol alkaline solution. Form Supplied in: colorless liquid, widely available. Purification: purified by drying over MgSO4 and distilling; a small acidic forerun is discarded. Handling, Storage, and Precautions: stable compound. It is advised not to distill large quantities at reduced pressure. Flammable; toxic. Gives shock- and heat-sensitive alkali and heavy metal salts. Do not dry the sodium salt.}, journal={Encyclopedia of Reagents for Organic Synthesis}, year={2012}, month={Sep} }
 @article{lindsay_nicolas_charette andré b._2011, title={Asymmetric Rh(II)-Catalyzed Cyclopropanation of Alkenes with Diacceptor Diazo Compounds:p-Methoxyphenyl Ketone as a General Stereoselectivity Controlling Group}, volume={133}, ISSN={0002-7863 1520-5126}, url={http://dx.doi.org/10.1021/ja201237j}, DOI={10.1021/ja201237j}, abstractNote={Different diacceptor diazo compounds bearing an α-PMP-ketone group were found to be effective carbene precursors for the highly stereoselective Rh(2)(S-TCPTTL)(4)-catalyzed cyclopropanation of alkenes (EWG = NO(2), CN, CO(2)Me). The resulting products were readily transformed into a variety of biologically relevant enantiopure molecules, such as cyclopropane α- and β-amino acid derivatives. Different mechanistic studies carried out led to a rationale for the high diastereo- and enantioselectivity obtained, where the PMP-ketone moiety was found to play a critical role in the stereoinduction process. Additionally, the use of catalytic amounts of achiral Lewis bases to influence the enantioinduction of the reactions developed is documented.}, number={23}, journal={Journal of the American Chemical Society}, publisher={American Chemical Society (ACS)}, author={Lindsay, Vincent N. G. and Nicolas, Cyril and Charette André B.}, year={2011}, month={Jun}, pages={8972–8981} }
 @inbook{cyclopropanation reactions_2011, booktitle={Stereoselective Synthesis: Stereoselective Reactions of Carbon-Carbon Double Bonds}, year={2011} }
 @misc{dirhodium(ii) tetrakis[n-tetrachlorophthaloyl-(s)-tert-leucinate]_2011, url={http://dx.doi.org/10.1002/047084289x.rn01265}, DOI={10.1002/047084289x.rn01265}, abstractNote={[515876-71-8] 
 
InChI = 1S/4C14H11Cl4NO4.2Rh/c4*1-14(2,3)10(13(22)23)19-11(20)4-5(12(19)21)7(16)9(18)8(17)6(4)15;;/h4*10H,1-3H3,(H,22,23);;/q;;;;2*+2/p-4/t4*10-;;/m1111../s1 
 
InChIKey = VOPFDGCIUABLIB-MYHKTDPMSA-J 
 
[1154062-34-6] C56H40N4O16Cl16Rh2 (MW 1798.0) 
 
InChI = 1S/4C14H11Cl4NO4.2Rh/c4*1-14(2,3)10(13(22)23)19-11(20)4-5(12(19)21)7(16)9(18)8(17)6(4)15;;/h4*10H,1-3H3,(H,22,23);;/q;;;;2*+2/p-4/t4*10-;;/m1111../s1 
 
InChIKey = VOPFDGCIUABLIB-MYHKTDPMSA-J 
 
 
 
 
 
(chiral catalyst for various enantioselective metal–carbene or metal–nitrene transformations: intermolecular cyclopropanation, CH insertion reactions, inter/intramolecular aziridination and, 1,3-dipolar cycloadditions) 
 
 
 
Alternative Name: Rh2(S-TCPTTL)4, Hashimoto's catalyst. 
 
 
 
Physical Data: mp >280 °C, (c 0.054, benzene), green solid.1 
 
 
 
Solubility: sol in most organic solvents, sparingly sol in hexane. 
 
 
 
Form Supplied in: not commercially available. 
 
 
 
Preparative Methods: the reagent is prepared from dirhodium tetraacetate by ligand exchange with N-tetrachlorophthaloyl-(S)-t-leucine according to the method of Callot.1, 2 
 
 
 
Purification: the title compound can be readily purified by column chromatography on silica gel using Et2O/benzene (1:15) as eluent followed by recrystallization from 1:1 hexane/EtOAc to provide the bis(ethyl acetate) adduct as green prisms.1 
 
 
 
Handling, Storage, and Precautions: air stable but hygroscopic.}, journal={Encyclopedia of Reagents for Organic Synthesis}, year={2011}, month={Mar} }
 @article{marcoux_lindsay_charette_2010, title={Use of achiral additives to increase the stereoselectivity in Rh(ii)-catalyzed cyclopropanations}, volume={46}, ISSN={1359-7345 1364-548X}, url={http://dx.doi.org/10.1039/b920587j}, DOI={10.1039/b920587j}, abstractNote={We describe our studies on the effect of various Lewis bases and Brønsted acids as achiral additives on the stereoselectivity of some Rh(ii)-catalyzed cyclopropanations.}, number={6}, journal={Chemical Communications}, publisher={Royal Society of Chemistry (RSC)}, author={Marcoux, David and Lindsay, Vincent N. G. and Charette, André B.}, year={2010}, pages={910} }
 @article{lindsay_lin_charette andré b._2009, title={Experimental Evidence for the All-Up Reactive Conformation of Chiral Rhodium(II) Carboxylate Catalysts: Enantioselective Synthesis ofcis-Cyclopropane α-Amino Acids}, volume={131}, ISSN={0002-7863 1520-5126}, url={http://dx.doi.org/10.1021/ja9044955}, DOI={10.1021/ja9044955}, abstractNote={Useful empirical insights onto the enantioinduction process of chiral Rh(II)-carboxylate catalysts are described in the first catalytic asymmetric cyclopropanation of alkenes with alpha-nitro diazoacetophenones. X-ray, solution NMR, and reactivity studies made on these complexes suggest that the level of asymmetric induction strongly depends on their active symmetry, which in turn relies on the nature of the chiral ligands' substituents. The catalyst's 'All Up' reactive conformation resulted in being necessary to obtain good stereoselectivity, and the resulting products are shown to be key intermediates in a concise synthesis of highly enantioenriched cis-cyclopropane alpha-amino acids.}, number={45}, journal={Journal of the American Chemical Society}, publisher={American Chemical Society (ACS)}, author={Lindsay, Vincent N. G. and Lin, Wei and Charette André B.}, year={2009}, month={Nov}, pages={16383–16385} }
 @article{charette_côté_desrosiers_bonnaventure_lindsay_lauzon_tannous_boezio_2008, title={New methods in asymmetric catalysis based on new hemi-labile bidentate ligands}, volume={80}, url={http://dx.doi.org/10.1351/pac200880050881}, DOI={10.1351/pac200880050881}, abstractNote={Abstract Chiral bidentate hemi-labile bis(phosphine) monoxide ligands were shown to be quite effective in various copper-catalyzed transformations. Among them, the nucleophilic addition to imines, the conjugate addition to α,β-unsaturated nitro derivatives, and the conjugate reduction of α,β-unsaturated sulfones generally gave good to excellent yields and high enantiomeric excesses.}, number={5}, journal={Pure and Applied Chemistry}, author={Charette, A. B. and Côté, A. and Desrosiers, J.-N. and Bonnaventure, I. and Lindsay, V.N.G. and Lauzon, C. and Tannous, J. and Boezio, A.A.}, year={2008}, pages={881–890} }
 @article{côté,_lindsay_charette_2007, title={Application of the Chiral Bis(phosphine) Monoxide Ligand to Catalytic Enantioselective Addition of Dialkylzinc Reagents to β-Nitroalkenes}, volume={9}, ISSN={1523-7060 1523-7052}, url={http://dx.doi.org/10.1021/ol062792t}, DOI={10.1021/ol062792t}, abstractNote={[reaction: see text] Me-DuPHOS monoxide is shown to be a very effective ligand in the enantioselective copper-catalyzed addition of dialkylzinc reagents to beta-nitroalkenes providing access to chiral nitroalkanes. The major advantages of this process are high yields, broad and complementary substrate scope, and high enantioselectivities. The effect of achiral dummy ligands as an additive has also been documented.}, number={1}, journal={Organic Letters}, publisher={American Chemical Society (ACS)}, author={Côté,, Alexandre and Lindsay, Vincent N. G. and Charette, André B.}, year={2007}, month={Jan}, pages={85–87} }
 @misc{dirhodium(ii) tetrakis[r 2-oxaazetidine-4(s)-carboxylate]_2005, url={http://dx.doi.org/10.1002/047084289x.rn00607}, DOI={10.1002/047084289x.rn00607}, abstractNote={Dirhodium(II) tetrakis[methyl-2-oxaazetidine-4(S)-carboxylate] Rh2(4S-MEAZ)4 
 
[271261-55-3] C20H24N4O12Rh2 (MW 718.22) 
 
InChI = 1S/4C5H7NO3.2Rh/c4*1-9-5(8)3-2-4(7)6-3;;/h4*3H,2H2,1H3,(H,6,7);;/q;;;;2*+2/p-4/t4*3-;;/m0000../s1 
 
InChIKey = JHTCYYXMMBICCX-AABFXYGWSA-J 
 
 
Dirhodium(II) tetrakis[isobutyl-2-oxaazetidine-4(S)-carboxylate] Rh2(4S-IBAZ)4 
 
[181628-69-3] C28H40N4O12Rh2 (MW 830.46) 
 
InChI = 1S/4C8H13NO3.2Rh/c4*1-5(2)4-12-8(11)6-3-7(10)9-6;;/h4*5-6H,3-4H2,1-2H3,(H,9,10);;/q;;;;2*+2/p-4/t4*6-;;/m0000../s1 
 
InChIKey = PJCHDVOEYNTBTL-FXSYQKBJSA-J 
 
 
Dirhodium(II) tetrakis[menthol-2-oxaazetidine-4(S)-carboxylate] Rh2(4S-MenthAZ)4 
 
[417712-41-5] C56H88N4O12Rh2 (MW 1215.14) 
 
InChI = 1S/4C14H23NO3.2Rh/c4*1-8(2)10-5-4-9(3)6-12(10)18-14(17)11-7-13(16)15-11;;/h4*8-12H,4-7H2,1-3H3,(H,15,16);;/q;;;;2*+2/p-4/t4*9?,10?,11-,12?;;/m0000../s1 
 
InChIKey = OOCLZLULKGWPLW-IADIKANBSA-J 
 
 
 
 
 
 
 
(reagents used for the decomposition of stablized diazo species as well as diazomalonate esters) 
 
 
 
Physical Data: Rh2(4S-MEAZ)4 [α]D25 = −214 (c, 0.7, CH3CN). Rh2(4S-IBAZ)4 [α]D25 = −211.4 (c, 0.69, CH3CN). Rh2(4S-MenthAZ)4 [α]D29.6 = −184 (c, 0.1, CHCl3). 
 
 
 
Form Supplied in: Rh2(4S-MEAZ)4: red crystalline solid as bis-acetonitrile, purple solid after removal of nitrile ligands;Rh2(4S-IBAZ)4: red crystalline solid as bis-acetonitrile, purple solid after removal of nitrile ligands;Rh2(4S,R-MenthAZ)4: blue solid. 
 
 
 
Preparative Method: ligand exchange from dirhodium(II) tetracetate by corresponding alkyl 2-oxaazetidine-4(S)-carboxylate. 
 
 
 
Handling, Storage, and Precautions: air stable, weakly hygroscopic, stored in desiccator.}, journal={Encyclopedia of Reagents for Organic Synthesis}, year={2005}, month={Oct} }