Asymmetric Intramolecular [3 + 2] Cycloaddition Reactions of Acylhydrazones/Olefins Using a Chiral Zirconium Catalyst

Catalytic asymmetric intramolecular [3 + 2] cycloaddition of hydrazone/olefins has been attained. In the presence of a chiral zirconium catalyst prepared from zirconium alkoxide and a BINOL derivative, the desired pyrazolidine derivatives were obtained in high yields with high selectivities. The products were easily converted to 1,3-diamine or β-aminonitrile derivatives by N−N bond cleavage.