The Mannich reaction between chiral N-phosphonyl imines and a Ni(II)-complexed alanine Schiff base (Ala-Ni) is reported. With a chiral phosphonyl auxiliary, a single isomer of alpha-methyl-alpha,beta-diamino acid derivative containing vicinal chiral centers, including a chiral quaternary carbon center, can be obtained simply by washing the crude mixture with cosolvents. The absolute stereochemistry of the enantiomerically pure product has been unambiguously determined by X-ray crystallographic analysis.
|Journal||Journal of Organic Chemistry|
|State||Published - Sep 2016|
Zhang, H., Yang, B., Yang, Z., Lu, H., & Li, G. (2016). Asymmetric Synthesis of Chiral alpha-Methyl-alpha,beta-diamino Acid Derivatives via Group-Assisted Purification Chemistry Using N-Phosphonyl Imines and a Ni(II)-Complexed Alanine Schiff Base. Journal of Organic Chemistry, 7654-7661.