@article{chen_pedersen_dow_fayad_hauke_rosko_danilov_blakemore_dechert-schmitt_knauber_et al._2022, title={A Unified Approach to Decarboxylative Halogenation of (Hetero)aryl Carboxylic Acids}, volume={144}, ISSN={["1520-5126"]}, url={https://doi.org/10.1021/jacs.2c02392}, DOI={10.1021/jacs.2c02392}, abstractNote={Aryl halides are a fundamental motif in synthetic chemistry, playing a critical role in metal-mediated cross-coupling reactions and serving as important scaffolds in drug discovery. Although thermal decarboxylative functionalization of aryl carboxylic acids has been extensively explored, the scope of existing halodecarboxylation methods remains limited, and there currently exists no unified strategy that provides access to any type of aryl halide from an aryl carboxylic acid precursor. Herein, we report a general catalytic method for direct decarboxylative halogenation of (hetero)aryl carboxylic acids via ligand-to-metal charge transfer. This strategy accommodates an exceptionally broad scope of substrates. We leverage an aryl radical intermediate toward divergent functionalization pathways: (1) atom transfer to access bromo- or iodo(hetero)arenes or (2) radical capture by copper and subsequent reductive elimination to generate chloro- or fluoro(hetero)arenes. The proposed ligand-to-metal charge transfer mechanism is supported through an array of spectroscopic studies.}, number={18}, journal={JOURNAL OF THE AMERICAN CHEMICAL SOCIETY}, publisher={American Chemical Society (ACS)}, author={Chen, Tiffany Q. and Pedersen, P. Scott and Dow, Nathan W. and Fayad, Remi and Hauke, Cory E. and Rosko, Michael C. and Danilov, Evgeny O. and Blakemore, David C. and Dechert-Schmitt, Anne-Marie and Knauber, Thomas and et al.}, year={2022}, month={May}, pages={8296–8305} }
 @article{reichle_sterzel_kreitmeier_fayad_castellano_rehbein_reiser_2022, title={Copper(ii)-photocatalyzed decarboxylative oxygenation of carboxylic acids}, volume={2}, ISSN={["1364-548X"]}, url={https://doi.org/10.1039/D2CC00570K}, DOI={10.1039/d2cc00570k}, abstractNote={Choosing the right coordination geometry for the light-induced Cu(ii)-catalyzed oxidative decarboxylation.}, number={28}, journal={CHEMICAL COMMUNICATIONS}, publisher={Royal Society of Chemistry (RSC)}, author={Reichle, Alexander and Sterzel, Hannes and Kreitmeier, Peter and Fayad, Remi and Castellano, Felix N. and Rehbein, Julia and Reiser, Oliver}, year={2022}, month={Feb} }
 @article{chen_pedersen_dow_fayad_hauke_rosko_danilov_blakemore_dechert-schmitt_knauber_et al._2021, title={Ligand-to-Copper Charge Transfer: A General Catalytic Approach to Aromatic Decarboxylative Functionalization}, volume={4}, url={http://dx.doi.org/10.26434/chemrxiv.14451117.v1}, DOI={10.26434/chemrxiv.14451117.v1}, abstractNote={Aryl carboxylic acids are valuable, stable, and abundant functional handles in organic synthesis. Historically, their activation with established two-electron methods requires forcing conditions, and such protocols are limited in scope. In contrast, we envisioned that copper’s ability to generate open-shell species through ligand-to-metal charge transfer (LMCT), combined with its unique capacity to act as a potential aroyloxy and aryl radical reservoir, could mediate facile light- and copper-enabled aromatic decarboxylative functionalization by mitigating undesired reactivity of radical intermediates formed during aromatic decarboxylation. We report herein a general copper-LMCT open-shell activation platform for aromatic halodecarboxylation. Catalytic decarboxylative chlorination, bromination, and iodination of diverse (hetero)aryl carboxylic acids have been achieved to provide broadly used electrophilic cross-coupling handles from widely available aromatic acid precursors. Notably, decarboxylative fluorination of aryl carboxylic acids ­– a long-standing challenge in the field of organic synthesis – is readily accessible over a wide breadth of (hetero)aryl substrates. Ultrafast transient absorption (TA) spectroscopy experiments in combination with steady-state UV-vis spectroscopy studies are consistent with the proposed copper-LMCT mechanism, supporting the mechanistic basis of this activation platform.}, journal={[]}, publisher={American Chemical Society (ACS)}, author={Chen, Tiffany and Pedersen, P. Scott and Dow, Nathan W. and Fayad, Remi and Hauke, Cory E. and Rosko, Michael C. and Danilov, Evgeny O. and Blakemore, David C. and Dechert-Schmitt, Anne-Marie and Knauber, Thomas and et al.}, year={2021}, month={Apr} }
 @article{karimi_tabei_fayad_saber_danilov_jones_castellano_gabbai_2021, title={Photodriven Elimination of Chlorine From Germanium and Platinum in a Dinuclear Pt-II -> Ge-IV Complex}, volume={8}, ISSN={["1521-3773"]}, url={http://dx.doi.org/10.1002/anie.202107485}, DOI={10.1002/anie.202107485}, abstractNote={Abstract}, journal={ANGEWANDTE CHEMIE-INTERNATIONAL EDITION}, publisher={Wiley}, author={Karimi, Mohammadjavad and Tabei, Elham S. and Fayad, Remi and Saber, Mohamed R. and Danilov, Evgeny O. and Jones, Cameron and Castellano, Felix N. and Gabbai, Francois P.}, year={2021}, month={Sep} }
 @article{fayad_engl_danilov_hauke_reiser_castellano_2020, title={Direct Evidence of Visible Light-Induced Homolysis in Chlorobis(2,9-dimethyl-1,10-phenanthroline)copper(II)}, volume={11}, ISSN={1948-7185 1948-7185}, url={http://dx.doi.org/10.1021/acs.jpclett.0c01601}, DOI={10.1021/acs.jpclett.0c01601}, abstractNote={Developments in the field of photoredox catalysis that leveraged the long-lived excited states of Ir(III) and Ru(II) photosensitizers to enable radical coupling processes, paved the way for explorations of synthetic transformations that would otherwise remain unrealized. While first row transition metal photocatalysts have not been as extensively investigated, valuable synthetic transformations covering broad scopes of olefin functionalization have been recently reported featuring photoactivated chlorobis(phenanthroline) Cu(II) complexes. In the current study, the photochemical processes underpinning the catalytic activity of [Cu(dmp)2Cl]Cl (dmp = 2,9-dimethyl-1,10-phenanthroline) were investigated. The combined results from static spectroscopic investigations and conventional photochemistry, ultrafast transient absorption, and electron paramagnetic resonance (EPR) spin trapping experiments, strongly support blue light (ex = 427 or 470 nm) induced Cu-Cl homolytic bond cleavage in [Cu(dmp)2Cl]+ occurring in less than 100 femtoseconds. Based on electronic structure calculations, this bond breaking photochemistry corresponds to the Cl → Cu(II) ligand-to-metal charge transfer (LMCT) transition, unmasking a Cu(I) species [Cu(dmp)2]+ and a Cl• atom, thereby serving as a departure point for both Cu(I)- or Cu(II)-based photoredox transformations. No net photochemistry was observed through direct excitation of the ligand-field transitions in the red (ex = 785 or 800 nm), and all combined experiments indicated no evidence of Cu-Cl bond cleavage under these conditions. The underlying visible light-induced homolysis (VLIH) of a metal-ligand bond yielding a one electron reduced photosensitizer and a radical species, may form the basis for novel photoredox transformations based on first row transition metal complexes.}, number={13}, journal={The Journal of Physical Chemistry Letters}, publisher={American Chemical Society (ACS)}, author={Fayad, Remi and Engl, Sebastian and Danilov, Evgeny O. and Hauke, Cory E. and Reiser, Oliver and Castellano, Felix N.}, year={2020}, month={Jun}, pages={5345–5349} }
 @article{fayad_bui_shepard_castellano_2020, title={Photochemical Upconversion in Water Using Cu(I) MLCT Excited States: Role of Energy Shuttling at the Micellar/Water Interface}, volume={3}, ISSN={2574-0962 2574-0962}, url={http://dx.doi.org/10.1021/acsaem.0c02492}, DOI={10.1021/acsaem.0c02492}, abstractNote={Photochemical upconversion (UC) through triplet–triplet annihilation (TTA), which employs a visible absorbing triplet photosensitizer and an annihilator, is a process that generates a high energy photon from two lower energy photons. TTA-UC has been largely developed in pure organic solvents and solid-state polymeric constructs while featuring near exclusive use of rare and expensive metals within the photosensitizer. In this current investigation, we demonstrate that TTA-UC from the long lifetime earth-abundant photosensitizer [Cu(dsbtmp)2](PF)6 (dsbtmp = 2,9-di(sec-butyl)-3,4,7,8-tetramethyl-1,10-phenanthroline), abbreviated as Cu-PS, functions in water through encapsulation within a cationic-based assembly. Cetyltrimethylammonium bromide was the surfactant of choice as it electrostatically binds the negatively charged water-soluble 10-phenylanthracene-9-carboxylate (PAC) acceptor/annihilator and ultimately facilitates energy transfer across the interface. Efficient triplet–triplet energy transfer (TTET) from Cu-PS to the PAC acceptor was achieved in this aqueous assembly. Unfortunately, the hindered mobility of the PAC moieties ultimately hampered the annihilation process, and this was reflected in attenuated TTA rates and efficiencies. The combined experimental data illustrated that the water-soluble PAC acceptor was able to vectorially deliver the excited-state energy stored in Cu-PS across the interface into the bulk aqueous solution by engaging in excited-state electron transfer with methyl viologen acceptors. These results are important for remotely operating photoredox reactions in water while rendering a photosensitizer spatially isolated in the hydrophobic core of a micelle.}, number={12}, journal={ACS Applied Energy Materials}, publisher={American Chemical Society (ACS)}, author={Fayad, Remi and Bui, Anh Thy and Shepard, Samuel G. and Castellano, Felix N.}, year={2020}, month={Dec}, pages={12557–12564} }
 @article{fayad_dhainy_ghandour_halaoui_2017, title={Electrochemical study of the promoting effect of Fe on oxygen evolution at thin ‘NiFe–Bi’ films and the inhibiting effect of Al in borate electrolyte}, volume={7}, url={https://doi.org/10.1039/C7CY00873B}, DOI={10.1039/C7CY00873B}, abstractNote={Adding Fe3+ or Al3+ to the electrolyte resulted in fast promotion or poisoning, respectively, of catalysis for oxygen evolution at nickel–borate, and both effects were accompanied with anodic shifts in the redox peaks with potential scanning.}, number={17}, journal={Catalysis Science & Technology}, publisher={Royal Society of Chemistry (RSC)}, author={Fayad, Remi and Dhainy, Jihan and Ghandour, Hiba and Halaoui, Lara}, year={2017}, pages={3876–3891} }
 @article{fayad_shoker_ghaddar_2016, title={High photo-currents with a zwitterionic thiocyanate-free dye in aqueous-based dye sensitized solar cells}, volume={45}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84962076530&partnerID=MN8TOARS}, DOI={10.1039/c6dt00071a}, abstractNote={A zwitterionic dye shows high photocurrent and incident photon to current efficiency in water based dye sensitized solar cells.}, number={13}, journal={Dalton Transactions}, author={Fayad, R. and Shoker, T.A. and Ghaddar, T.H.}, year={2016}, pages={5622–5628} }
 @article{fayad_halaoui_2016, title={The Role of Order in the Amplification of Light-Energy Conversion in a Dye-Sensitized Solar Cell Coupled to a Photonic Crystal}, volume={17}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84956578259&partnerID=MN8TOARS}, DOI={10.1002/cphc.201500942}, abstractNote={Abstract}, number={2}, journal={ChemPhysChem}, author={Fayad, R. and Halaoui, L.}, year={2016}, pages={260–269} }
 @article{shoker_tanios_fayad_ghaddar_2015, title={Highly robust tetrazolate based complexes for efficient and long-term stable dye sensitized solar cells}, volume={5}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84938809559&partnerID=MN8TOARS}, DOI={10.1039/c5ra11984g}, abstractNote={We report a new family of RuII complexes that bear tetrazolate based ligands with superb long-term stability.}, number={81}, journal={RSC Advances}, author={Shoker, T.A. and Tanios, R. and Fayad, R. and Ghaddar, T.H.}, year={2015}, pages={66047–66056} }