Highly Diastereoselective Functionalization of Piperidines by Photoredox-Catalyzed α-Amino C-H Arylation and Epimerization.

ABSTRACT: We report a photoredox-catalyzed α-amino C-H arylation reaction of highly substituted piperidine derivatives with electron-deficient cyano(hetero)arenes. The scope and limitations of the reaction were explored, with piperidines bearing multiple substitution patterns providing the arylated products in good yields and with high diastereoselectivity. To probe the mechanism of the overall transformation, optical and fluorescent spectroscopic methods were used to investigate the reaction. By employing flash-quench transient absorption spectroscopy, we were able to observe electron transfer processes associated with radical formation beyond the initial excited-state Ir(ppy)₃ oxidation. Following the rapid and unselective C-H arylation reaction, a slower epimerization occurs to provide

SUBMITTER: Walker MM 

PROVIDER: S-EPMC7318553 | biostudies-literature | 2020 May

REPOSITORIES: biostudies-literature