Photoredox-Catalyzed gem-Difluoromethylenation of Aliphatic Alcohols with 1,1-Difluoroalkenes to Access α,α-Difluoromethylene Ethers

Abstract

A switchable synthesis of alcohols and ketones bearing a CF 2 −OR scaffold using visible-light promotion is described. The method of PDI catalysis is characterized by its ease of operation, broad substrate scopes, and the ability to switch between desired products without the need for transition metal catalysts. The addition or absence of a base plays a key role in controlling the synthesis of the major desired products.

Difunctionalization of gem-difluoroalkenes for amination and heteroarylation via metal-free photocatalysis

“…8–10 Recent research on functionalization of gem -difluoroalkenes has mainly focused on the construction of C–X (X = OR, SR, etc. ) or C(sp3)–C(sp3) bonds, involving the introduction of some functional groups such as alkyl, 11–13 alkoxyl, 14,15 alkylthiol, 16,17 sulfonyl 18 and other groups (Scheme 1a). 9,10,19,20 However, there are only a few reports on the introduction of aromatic groups to gem -difluoroalkenes, and previous reports focused on transitional-metal catalyzed coupling reactions (Scheme 1a).…”