The bromodifluoromethylation of lithium enolates of chiral N-acyloxazolidinones via the insertion of difluorocarbene proceeds with good diastereomeric excess (68–92% de).
Lithium enolates of chiral N-acyloxazolidinones reacted with dibromodifluoromethane and bromodifluoromethane to give α-bromodifluoromethyl and α-difluoromethyl carboximides, respectively, with good diastereomeric excess. These reactions proceed not via a radical mechanism but via an ionic chain mechanism involving insertion of difluorocarbene.