Asymmetric NHC-catalyzed synthesis of α-fluoroamides from readily accessible α-fluoroenals†
Abstract
The scope of the NHC-redox amidation has been expanded to include a variety of α,β-unsaturated aldehydes, including α-fluoro α,β-unsaturated aldehydes which give rise to enantioenriched α-fluoroamides in good to excellent yield and enantioselectivity (up to 97% ee). Enantioenriched amines may be elaborated to either diastereomer of the product in high diastereoselectivity (up to 99 : 1). Functionalization of the amide products to amines and fluorohydrins is also demonstrated with retention of enantioenrichment at the fluorine stereocenter.