An alternative to the classical α-arylation: the transfer of an intact 2-iodoaryl from ArI(O₂CCF₃)₂

Abstract

The α-arylation of carbonyl compounds is generally accomplished under basic conditions, both under metal catalysis and via aryl transfer from the diaryl λ(3)-iodanes. Here, we describe an alternative metal-free α-arylation using ArI(O2CCF3)2 as the source of a 2-iodoaryl group. The reaction is applicable to activated ketones, such as α-cyanoketones, and works with substituted aryliodanes. This formal C-H functionalization reaction is thought to proceed through a [3,3] rearrangement of an iodonium enolate. The final α-(2-iodoaryl)ketones are versatile synthetic building blocks.

Keywords: CH functionalization; dehydrogenative CC coupling; hypervalent iodine; iodonium-Claisen rearrangement; α-arylation.