Synthesis of Propargyl Boranes via Silver Catalyzed Insertion of Alkynyl Carbene into B‐H Bond

Abstract

AbstractA silver‐catalyzed insertion reaction of alkynyl carbenes derived in situ by decomposition of alkynyl N‐nosylhydrazones, into a B−H bond is reported. This protocol emerges as a straightforward synthesis of various propargylic boron compounds with up to 95 % yield. The operationally simple method exhibits high functional group tolerance and produces a variety of propargyl boranes which are synthetically useful building blocks. Deuterium labelling experiment and DFT studies show that the reaction proceeds via insertion of alkynyl Ag‐carbene into the B−H bond and generation of silver carbene occurs in the rate‐determining step.