An Efficient Protocol to Synthesize N-Acyl-enamides and -Imines by Pd-Catalyzed Carbonylations

For the first time, the bidentate phosphinite ligand 1,2-bis(di-tert-butylphosphinoxy) ethane (tBu(2)POCH(2)-CH2OPtBu2) was synthesized. In the presence of this ligand, various N-acyl enamides were obtained in good yields and chemoselectivity by Pd-catalyzed carbonylation reaction of imines containing alpha-H. Meanwhile, imines without alpha-H could be transformed to N-acyl imines, which form highly hindered amides by straightforward addition of Grignard reagents.