@article{geier_ciringh_li_haynes_lindsey_2000, title={A survey of acid catalysts for use in two-step, one-flask syntheses of meso-substituted porphyrinic macrocycles}, volume={2}, ISSN={["1523-7060"]}, DOI={10.1021/ol005917h}, abstractNote={[reaction: see text] Diverse Lewis acids and Bronsted acids were examined in the two-step, one-flask synthesis of meso-tetraphenylporphyrin, N-confused tetraphenylporphyrin, and tetraphenylsapphyrin. The scope of acid catalysis was found to be very broad, with 35 of 45 acids providing TPP in yields ranging from 5% to 58%. NC-TPP was also widely observed in yields of 1-40%, and TPS was infrequently observed in yields of <1%. Additionally, conditions were found for direct preparation of magnesium TPP and copper TPP.}, number={12}, journal={ORGANIC LETTERS}, author={Geier, GR and Ciringh, Y and Li, FR and Haynes, DM and Lindsey, JS}, year={2000}, month={Jun}, pages={1745–1748} }
 @article{wagner_ciringh_clausen_lindsey_1999, title={Investigation and refinement of palladium-coupling conditions for the synthesis of diarylethyne-linked multiporphyrin arrays}, volume={11}, ISSN={["0897-4756"]}, DOI={10.1021/cm9903529}, abstractNote={The synthesis of diarylethyne-linked multiporphyrin arrays requires Pd-mediated coupling conditions that are performed in dilute solution in the absence of copper and that give reaction mixtures that are easily purified. We previously developed copper-free Pd-mediated coupling conditions (Pd2(dba)3 and AsPh3 in toluene/triethylamine (5:1) at 35 °C) but extensive chromatography was required to remove unidentified porphyrinic byproducts. We have used laser-desorption mass spectrometry (LD-MS) and analytical size-exclusion chromatography (SEC) to assay the products from the coupling reaction of a zinc(II) iodophenylporphyrin (ZnI) and a zinc(II) ethynylphenylporphyrin (ZnU‘). Analysis of the crude reaction mixture revealed the diphenylethyne-linked dimer (Zn2U) as the major product, byproducts plausibly derived from phenyl−aryl exchange processes (a phenylated derivative of ZnU‘, a Ph2As-substituted derivative of ZnI), byproducts believed to originate from direct phenylation processes (a phenylated derivativ...}, number={10}, journal={CHEMISTRY OF MATERIALS}, author={Wagner, RW and Ciringh, Y and Clausen, C and Lindsey, JS}, year={1999}, month={Oct}, pages={2974–2983} }
 @article{littler_ciringh_lindsey_1999, title={Investigation of conditions giving minimal scrambling in the synthesis of trans-porphyrins from dipyrromethanes and aldehydes}, volume={64}, ISSN={["0022-3263"]}, DOI={10.1021/jo982452o}, abstractNote={A diverse range of reaction conditions for the MacDonald-type 2 + 2 condensation of a 5-substituted dipyrromethane and an aldehyde has been studied with the goal of eliminating acid-catalyzed polypyrrolic rearrangement reactions in the synthesis of trans-porphyrins. A rapid screening method based on laser desorption mass spectrometry has enabled the degree of rearrangement to be examined as a function of the acid catalyst, reagent concentration, reagent stoichiometry, solvent, salts, and temperature. For condensations involving 5-mesityldipyrromethane, we identified reaction at 10 mM concentration in CH(2)Cl(2) with 17.8 mM TFA as optimal conditions for suppression of the rearrangement reaction. A synthetic procedure based on these conditions allowed the expedient synthesis of multigram batches of eight trans-porphyrins in 48-14% yield from 5-mesityldipyrromethane, with minimal chromatography. The same conditions were also effective for the synthesis of two trans-porphyrins derived from 5-(2,6-dichlorophenyl)dipyrromethane. Application of the same conditions to condensations involving 5-phenyldipyrromethane showed extensive rearrangement. Examination of a wide range of conditions showed that slow reactions are associated with less rearrangement. Two sets of conditions were identified that gave little or no scrambling: (1) condensation at 10 mM in MeCN at 0 degrees C with BF(3).Et(2)O catalysis in the presence of NH(4)Cl followed by DDQ oxidation and (2) condensation at 0.1 M in DMSO at 100 degrees C in the presence of NH(4)Cl (with no added acid catalyst) with air oxidation. Although yields are typically less than 10%, the elimination of the need to perform tedious chromatography improves the methodology available for the preparation of trans-porphyrins, derived from sterically unhindered dipyrromethanes.}, number={8}, journal={JOURNAL OF ORGANIC CHEMISTRY}, author={Littler, BJ and Ciringh, Y and Lindsey, JS}, year={1999}, month={Apr}, pages={2864–2872} }
 @article{ciringh_lindsey_1998, title={Analysis of sugar phosphates and related compounds using capillary zone electrophoresis with indirect UV detection}, volume={816}, ISSN={["0021-9673"]}, DOI={10.1016/S0021-9673(98)00488-9}, abstractNote={Sugar phosphates and related compounds can be rapidly separated using capillary zone electrophoresis and quantitated via indirect UV detection using potassium sorbate at 256 nm. Three buffers were examined at various pH values. The optimum separation conditions resulted with 6 mM potassium sorbate at pH 5.8. Pairs of regioisomers such as glucose-1-phosphate and glucose-6-phosphate or ribose-1-phosphate and ribose-5-phosphate were readily separated. A mixture of seven sugar phosphates and orthophosphate also was separated. The detection limits for samples of glucose-6-phosphate and glucose-1-phosphate were 0.14 mM and 0.26 mM, respectively.}, number={2}, journal={JOURNAL OF CHROMATOGRAPHY A}, author={Ciringh, Y and Lindsey, JS}, year={1998}, month={Aug}, pages={251–259} }
 @article{li_yang_ciringh_seth_martin_singh_kim_birge_bocian_holten_et al._1998, title={Design, synthesis, and photodynamics of light-harvesting arrays comprised of a porphyrin and one, two, or eight boron-dipyrrin accessory pigments}, volume={120}, ISSN={["0002-7863"]}, DOI={10.1021/ja9812047}, abstractNote={Light-harvesting arrays containing one, two, or eight boron-dipyrrin (BDPY) pigments and one porphyrin (free base or Zn chelate) have been synthesized using a modular building block approach. The reaction of pyrrole and 4-(BDPY)benzaldehyde or 3,5-bis(BDPY)benzaldehyde, prepared by Pd-mediated ethynylation with the corresponding iodo-benzaldehydes, affords the desired BDPY-porphyrin array in yields of 10−58%. The arrays are soluble in organic solvents and have been characterized by static and time-resolved absorption and fluorescence spectroscopy. The blue-green BDPY absorption complements spectral coverage of the porphyrin chromophores and rivals the intensity of the porphyrin Soret band when eight BDPY accessory pigments are present. Efficient energy transfer from the BDPY pigment(s) to the porphyrin (free base or Zn-chelate) is observed in arrays containing one or two (>90%) or eight (>85%) accessory pigments per porphyrin. Biphasic excited-state decay behavior is exhibited by the BDPY pigments in isol...}, number={39}, journal={JOURNAL OF THE AMERICAN CHEMICAL SOCIETY}, author={Li, FR and Yang, SI and Ciringh, YZ and Seth, J and Martin, CH and Singh, DL and Kim, DH and Birge, RR and Bocian, DF and Holten, D and et al.}, year={1998}, month={Oct}, pages={10001–10017} }