Chiral amido- and diamidophosphites with a peripheral pyridine ring in Pd-catalyzed asymmetric allylation

Abstract

New chiral amidophosphite and diamidophosphite ligands with exocyclic pyridyl-containing substituents were obtained. Their efficiency in the Pd-catalyzed enantioselective allylic substitution was compared: in the sulfonylation of (E)-1,3-diphenylallyl acetate with sodium p-toluenesulfinate, the ee can reach 77%; its alkylation with dimethyl malonate and amination with pyrrolidine gave up to 80% and 74% ee, respectively. The asymmetric alkylation of cinnamyl acetate with ethyl 2-oxocyclohexanecarboxylate can provide to 68% ee. The complexation of zinc(ii) 5,10,15,20-tetraphenylporphyrinate with diamidophosphite ligand and its influence on conversion and enantioselectivity of the process were studied.