Cu- and Pd-catalyzed asymmetric one-pot tandem addition-cyclization reaction of 2-(2',3'-alkadienyl)-beta-keto esters, organic halides, and dibenzyl azodicarboxylate: an effective protocol for the enantioselective synthesis of pyrazolidine derivatives.

[reaction: see text] Optically active pyrazolidine derivatives have been constructed by the Cu- and Pd-catalyzed asymmetric one-pot tandem addition-cyclization reaction of 2-(2',3'-dienyl)-beta-ketoesters, organic halides, and dibenzyl azodicarboxylate. The absolute configurations of the final products depend on the structure of the ligand.