Strongly Reducing, Visible-Light Organic Photoredox Catalysts as Sustainable Alternatives to Precious Metals

Ya Du; Ryan M Pearson; Chern-Hooi Lim; Steven M Sartor; Matthew D Ryan; Haishen Yang; Niels H Damrauer; Garret M Miyake

doi:10.1002/chem.201702926

Strongly Reducing, Visible-Light Organic Photoredox Catalysts as Sustainable Alternatives to Precious Metals

Chemistry. 2017 Aug 16;23(46):10962-10968. doi: 10.1002/chem.201702926. Epub 2017 Aug 1.

Authors

Ya Du¹, Ryan M Pearson¹, Chern-Hooi Lim¹, Steven M Sartor¹, Matthew D Ryan¹, Haishen Yang^{1

2}, Niels H Damrauer^{1

3}, Garret M Miyake^{1

3}

Affiliations

¹ Department of Chemistry and Biochemistry, University of Colorado at Boulder, 215 UCB, Boulder, Colorado, 80309-0215, USA.
² Shanghai Key Laboratory of Materials Protection and Advanced Materials in Electric Power, College of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai, 200090, P. R. China.
³ Materials Science and Engineering Program, University of Colorado at Boulder, 596 UCB, Boulder, Colorado, 80309-0596, USA.

Abstract

Photoredox catalysis is a versatile approach for the construction of challenging covalent bonds under mild reaction conditions, commonly using photoredox catalysts (PCs) derived from precious metals. As such, there is need to develop organic analogues as sustainable replacements. Although several organic PCs have been introduced, there remains a lack of strongly reducing, visible-light organic PCs. Herein, we establish the critical photophysical and electrochemical characteristics of both a dihydrophenazine and a phenoxazine system that enables their success as strongly reducing, visible-light PCs for trifluoromethylation reactions and dual photoredox/nickel-catalyzed C-N and C-S cross-coupling reactions, both of which have been historically exclusive to precious metal PCs.

Keywords: organocatalysis; photocatalysis; photochemistry; radicals; sustainable chemistry.

Abstract

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