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Light-Driven Deracemization Enabled by Excited-State Electron Transfer

preprint
submitted on 30.05.2019 and posted on 31.05.2019 by Nick Shin, Jonathan Ryss, Xin Zhang, Scott Miller, Robert Knowles
A new strategy for catalytic deracemization is presented, wherein amine derivatives undergo spontaneous optical enrichment upon exposure to visible light in the presence of three distinct molecular catalysts. Initiated by an excited-state iridium chromophore, this reaction proceeds via a sequence of favorable electron, proton, and hydrogen atom transfer steps that serve to break and reform a stereogenic C–H bond. The enantioselectivity in these reactions is jointly determined by two independent stereoselective steps that occur in sequence within the catalytic cycle, giving rise to a composite selectivity that is higher than that of either step individually. These reactions represent a distinct and potentially general approach to creating out-of-equilibrium product distributions between substrate enantiomers using excited-state redox events.

Funding

NIH R01 GM120530 (RRK)

NIH R35 GM132092 (SJM)

History

Email Address of Submitting Author

rknowles@princeton.edu

Institution

Princeton University

Country

USA

ORCID For Submitting Author

0000-0003-1044-4900

Declaration of Conflict of Interest

No conflict of interest

Exports