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

Be selective: δ‐Azido, δ‐cyano, and δ‐thiocyanato alcohols were obtained in high yields from N‐alkoxypyridinium salts under mild dual photoredox/copper catalysis. A catalytic enantioselective δ‐cyanation protocol in the presence of a chiral bisoxazoline ligand was also developed.

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.

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