Halogen-Imparted Reactivity in Lithium Carbenoid Mediated Homologations of Imine Surrogates: Direct Assembly of bis-Trifluoromethyl-b-Diketiminates and the Dual Role of LiCH2I

Abstract

The selective formal insertion (homologation) of a carbon unit bridging the two trifluoroacetamidoyl chlorides (TFAICs) units is reported. The tactic is levered on a highly chemoselective homologation–metalation–acyl nucleophilic substitution sequence which precisely enables to assemble novel trifluoromethylated b-diketiminates within a single syn thetic operation. Unlike previous homologations conducted with LiCH2Cl furnishing aziridines, herein we exploit the unique capability of iodomethyllithium to act contemporane ously as a C1 source (homologating effect) and metalating agent. The mechanistic rationale grounded on experimental evidences supports the hypothesized proposal and, the struc tural analysis gathers key aspects of this class of valuable ligands in catalysis