title: Asymmetric aza-Mannich addition of oxazolones to N-tosyl aldimines: synthesis of chiral alpha-disubstituted alpha,beta-diamino acids.
abstract: An organocatalytic enantioselective addition of oxazolones to N-tosyl aldimines has been developed. The process is promoted by a readily prepared cinchona alkaloid ligand and affords a series of valuable alpha-disubstituted alpha,beta-diamino acid derivatives with excellent enantioselectivities (up to 97% ee) and diastereoselectivities (up to >30:1 dr). The adducts can be transformed into the corresponding protected chiral alpha-disubstituted alpha,beta-diamino acids by a one-pot hydrolyzed reaction smoothly.
authors.affiliation: State Key Laboratory of Applied Organic Chemistry, Institute of Biochemistry and Molecular Biology, Key Laboratory of Preclinical Study for New Drugs of Gansu Province, Lanzhou University, Lanzhou 730000, China.
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Liu
authors.forename: Leijiao
authors.initials: L
authors.lastname: Deng
authors.forename: Xianxing
authors.initials: X
authors.lastname: Jiang
authors.forename: Wenjin
authors.initials: W
authors.lastname: Yan
authors.forename: Chunliang
authors.initials: C
authors.lastname: Liu
authors.forename: Rui
authors.initials: R
authors.lastname: Wang
mesh_terms: D000599:Amino Acids, Diamino / Q000138:chemical synthesis* / Q000737:chemistry; D002384:Catalysis; D020650:Combinatorial Chemistry Techniques; D015394:Molecular Structure; D010081:Oxazolone / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D000599:Amino Acids, Diamino; D010081:Oxazolone