Oxidative enantioselective α-fluorination of aliphatic aldehydes enabled by N-heterocyclic carbene catalysis

Abstract

Described is the first study on oxidative enantioselective α-fluorination of simple aliphatic aldehydes enabled by N-heterocyclic carbene catalysis. N-fluorobis(phenyl)sulfonimide serves as a an oxidant and as an "F" source. The C-F bond formation occurs directly at the α position of simple aliphatic aldehydes, thus overcoming nontrivial challenges, such as competitive difluorination and nonfluorination, and proceeds with high to excellent enantioselectivities.

Keywords: N-heterocyclic carbenes; aldehydes; enolates; fluorine; oxidation.