Synthesis of Novel Bidentate P-Chiral Diaminophosphine Oxide Preligands: Application to Pd-Catalyzed Asymmetric Allylic Substitution Reactions

Abstract

We developed a novel (S)-L-phenylalanine derived-bidentate chiral diaminophosphine oxide (DIAPHOX) preligand (S,S P )-9b, which was successfully applied to Pd-catalyzed asymmetric allylic alkylation and amination. Using the Pd-(S,S P )-9b catalyst system, asymmetric allylic alkylation and amination proceeded very smoothly, affording the corresponding products in excellent yield with high enantiomeric excess. It is noteworthy that both enantiomers were accessible with high enantiomeric purity using the structurally related DIAPHOX preligands (S,S P )-9b and a monodentate chiral diaminophosphine oxide preligand (S,R P )-10a, both of which can be prepared from a single chiral source, (S)-L-phenylalanine.Key word chiral diaminophosphine oxide; asymmetric allylic substitution; palladium; asymmetric catalysis; preligand Chem. Pharm. Bull. 59(3) 412-415 (2011)

Recent Advances in Enantioselective Pd-Catalyzed Allylic Substitution: From Design to Applications

“…Several types of heterodonor P,P′-ligands were evaluated in Pd-catalyzed allylations, most of them heterodonor phosphine-containing ligands (e.g., phosphine-phosphoramidite, phosphine-diaminophosphine oxide and phosphine-phosphite), − although phosphite-phosphoramidite ligands generally performed better in terms of enantioselectivitiy and substrate scope. − Of the latter group, we highlight two families, ligands of type L53 derived from 1,2-amino alcohols and L54 with a furanoside backbone . All of them share the advantage of a modular structure and short syntheses from readily available starting materials and are also air stable.…”