Pd-catalyzed reductive cleavage of NN bond in dibenzyl-1-alkylhydrazine-1,2-dicarboxylates with PMHS: application to a formal enantioselective synthesis of (R)-sitagliptin

A one-step Pd-catalyzed direct conversion of dibenzyl-1-alkylhydrazine-1,2-dicarboxylates to various reactive intermediates using PMHS as a hydride source in an environmentally benign fashion is described.