Dual Photoredox/Copper Catalysis for the Remote C(sp3 )-H Functionalization of Alcohols and Alkyl Halides by N-Alkoxypyridinium Salts.

Abstract

Under mild dual photoredox/copper catalysis, the reaction of N-alkoxypyridinium salts with readily available silyl reagents (TMSN3 , TMSCN, TMSNCS) afforded δ-azido, δ-cyano, and δ-thiocyanato alcohols in high yields. The reaction went through a domino process involving alkoxy radical generation, 1,5-hydrogen atom transfer (1,5-HAT) and copper-catalyzed functionalization of the resulting C-centered radical. Conditions for catalytic enantioselective δ-C(sp3 )-H cyanation were also documented.