Barbier Continuous Flow Preparation and Reactions of Carbamoyllithiums for Nucleophilic Amidation

Abstract

An ambient temperature continuous flow method for nucleophilic amidation and thioamidation is described. Deprotonation of formamides by lithium diisopropylamine (LDA) affords carbamoyllithium intermediates that are quenched in situ with various electrophiles such as ketones, allyl bromides, Weinreb and morpholino amides. The nature of the reactive lithium intermediates and the thermodynamics of the metalation were further investigated by ab initio calculations and kinetic experiments.

Keywords: Barbier reaction; acidity; amidation; flow chemistry; lithiation.