Photo-induced copper-catalyzed sequential 1,n-HAT enabling the formation of cyclobutanols

Nat Commun. 2021 Nov 4;12(1):6404. doi: 10.1038/s41467-021-26670-5.

Abstract

Cyclobutanols are privileged cyclic skeletons in natural products and synthetic building blocks. C(sp3)-H functionalization is a prolonged challenge in organic synthesis. The synthesis of cyclobutanols through double C(sp3)-H bond functionalization remains elusive. Here we report the efficient synthesis of cyclobutanols through intermolecular radical [3 + 1] cascade cyclization, involving the functionalization of two C - H bonds through sequential hydrogen atom transfer. The copper complex reduces the iodomethylsilyl alcohols efficiently under blue-light irradiation to initiate the tandem transformation. The mild reaction tolerates a broad range of functional groups and allows for the facile generation of elaborate polycyclic structures.