Mannich type reactions of acylhydrazones with silyl enolates for the synthesis of beta-amino ester, beta-amino ketone, beta-lactam, pyrazolidinone, and pyrazolone derivatives

In the presence of a catalytic amount of a rare earth triflate, acylhydrazo nes reacted with silyl enolates to afford the corresponding beta-N'-acylhyd razino esters in high yields. A three-component reaction of an aldehyde, an acylhydrazine, and a silyl enolate was also performed successfully. The hy drazino eaters thus obtained were readily converted to beta-amino ester, be ta-amino ketone, beta-lactam, pyrazolidinone, and pyrazolinone derivatives.