Rimkus, Audrius;Sewald, Norbert published 《First Synthesis of a β2-Homoamino Acid by Enantioselective Catalysis》. The research results were published in《Organic Letters》 in 2003.Formula: C38H34NO2P The article conveys some information:
The enantioselective conjugate addition of diethylzinc to the activated nitroolefin Me 3-nitropropenoate is efficiently catalyzed by copper(I) complexes with BINOL-based enantiopure phosphoramidite ligands. The nitroolefin moiety acts as the predominant Michael acceptor, giving rise to the unambiguous formation of Me 2-ethyl-3-nitropropanoate. Moderate to excellent enantioselectivities and high chem. yields are obtained. The product can easily be transformed into a β2-homoamino acid, 2-[(tert-butoxycarbonyl)aminomethyl]butanoic acid. And (11bS)-2,6-Dimethyl-N,N-bis(1-phenylethyl)dinaphtho[2,1-d:1′,2′-f][1,3,2]dioxaphosphepin-4-amine (cas: 201732-49-2) was used in the research process.
(11bS)-2,6-Dimethyl-N,N-bis(1-phenylethyl)dinaphtho[2,1-d:1′,2′-f][1,3,2]dioxaphosphepin-4-amine(cas: 201732-49-2) is a compound of chiral-phosphine-ligands. At present, the synthesis of new chiral phosphines designed specifically for nucleophilic organocatalysis remains a significant challenge.Formula: C38H34NO2P
Reference:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis