Palladium-catalyzed coupling of propargylic carbonates with N-tosylhydrazones: Highly selective synthesis of substituted propargylic N-sulfonylhydrazones and vinylallenes
An efficient palladium-catalyzed coupling of propargylic carbonates (1) with N-tosylhydrazones (2, 2′) has been carried out. A wide range of propargylic N-sulfonylhydrazones (3) and multisubstituted vinylallenes (4) can be obtained selectively by using either [PdCl2(CH3CN) 2] or [Pd2(dba)3] as catalysts. (dba=trans,trans-dibenzylideneacetone, dppp=propane-l,3- diylbis(diphenylphosphane), Ts=4-toluenesulfonyl.) Copyright