ortho-Lithiation Reactions of O-(3,n-Dihalophenyl) N,N-Diethylcarbamates: Synthesis of Dihalosalicylamides and 2,3,n-Trihalophenol Derivatives

摘要

New dihalosalicylamides and trihalophenol derivatives have been synthesized from easily available O-(3,n-dihalophenyl) N,N-diethylcarbamates by using a directed ortho-metalation (DoM) strategy. The o-lithiation reactions with sBuLi take place regioselectively at the doubly activated C-2 position, which demonstrates the ability of O-carbamates as directed metalating groups. In addition, highly functionalized arylnitriles were accessed from organolithium intermediates by using a tandem transnitrilation/SNAr reaction sequence.