Pd-catalyzed arylative annulation of alkynyl nitriles with boronic acids to functionalized cyclopenten-3-ones/2-indenones

Abstract

Herein, we describe a novel arylative cyclization of enynyl-nitriles, obtained from Morita–Baylis–Hillman (MBH) acetates of propiolaldehydes, with boronic acids leading to cyclopenten-3-ones. The reaction proceeds through palladium-catalysed arylation/nucleophilic cyclization/hydrolysis. The method has been extended to alkynyl benzyl-nitriles for the construction of 2-indenones. The synthetic utility of this approach was also demonstrated by further conversions of cyclopentenones.