title: Asymmetric C-C Bond Formation between ChiralN-Phosphonyl Imines and Ni(II)-Complex of Glycine Schiff Base Provides a GAP Synthesis of α,β-syn-Diamino Acid Derivatives.
abstract: The GAP asymmetric synthesis of α,β-diamino acid derivatives has been achieved by reacting chiral N-phosphonyl imines with Ni(II)-complex of glycine ester-based enolate without the use of traditional purifications of chromatography and recrystallization. The successful control of synstereochemistry of vicinal diamino products complements our previous methods which afforded anti stereoisomers and enables all four individual isomers to be synthesized by simply changing enolate geometry. In contrast to our previous synthesis where required at least 5 equiv of glycine Schiff base enolate for complete conversion, the new synthesis only needs 1.1 equiv of glycine Schiff base enolate to give complete diastereoselectivity (>99% de) and yields (91% - 97%). The absolute stereochemistry has been unambiguously determined by X-ray structural analysis.
authors.affiliation: School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, P. R. China ; Institute of Chemistry & BioMedical Sciences, Nanjing University, Nanjing 210093, P. R. China.
authors.forename: Hao
authors.initials: H
authors.lastname: Sun
authors.affiliation: School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, P. R. China ; Institute of Chemistry & BioMedical Sciences, Nanjing University, Nanjing 210093, P. R. China.
authors.forename: Haowei
authors.initials: H
authors.lastname: Zhang
authors.affiliation: School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, P. R. China ; Institute of Chemistry & BioMedical Sciences, Nanjing University, Nanjing 210093, P. R. China.
authors.forename: Jianlin
authors.initials: J
authors.lastname: Han
authors.affiliation: School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, P. R. China ; Institute of Chemistry & BioMedical Sciences, Nanjing University, Nanjing 210093, P. R. China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Pan
authors.affiliation: Institute of Chemistry & BioMedical Sciences, Nanjing University, Nanjing 210093, P. R. China ; Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409-1061, USA.
authors.forename: Guigen
authors.initials: G
authors.lastname: Li