Regioselective synthesis of spiro-cyclopropanated 1-aminopyrrol-2-ones by Bi(OTf)3-catalyzed one-pot ‘Mukaiyama–Michael addition/cyclization/ring-contraction’ reactions of 1,2-bis(trimethylsilyloxy)cyclobutene with 1,2-diaza-1,3-butadienes

Abstract Unknown spiro-cyclopropanated 1-aminopyrrol-2-ones are regioselectively prepared in high yields by Bi(OTf) 3 -catalyzed one-pot ‘Mukaiyama–Michael addition/cyclization/ring-contraction’ reactions of 1,2-bis(trimethylsilyloxy)cyclobutene with 1,2-diaza-1,3-butadienes at room temperature.