USE OF ACYLHYDRAZONES AS ELECTROPHILES IN MANNICH-TYPE REACTIONS, BETA-LACTAM, PYRAZOLIDINONE, AND PYRAZOLONE SYNTHESIS

In the presence of a catalytic amount of scandium triflate [Sc(OTf)(3) ], 4-trifluoromethylbenzoylhydrazones reacted with silyl enolates to a fford the corresponding adducts, beta-N'-acylhydrazinocarbonyl compoun ds, in high yields. Reductive cleavage of the nitrogen-nitrogen bond o f the hydrazino compounds was performed using Raney Ni under H-2 atmos phere, to give beta-aminocarbonyl compounds. The two-step process is r egarded as a novel Mannich-type reaction using acylhydrazones as elect rophiles. Moreover, the hydrazino compounds were also successfully con verted to beta-lactam, pyrazolidinone, and pyrazolone derivatives.