Asymmetric aza-Mannich addition of oxazolones to N-tosyl aldimines: synthesis of chiral alpha-disubstituted alpha,beta-diamino acids.
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.
Liu
Xiaodong
X
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.
Deng
Leijiao
L
Jiang
Xianxing
X
Yan
Wenjin
W
Liu
Chunliang
C
Wang
Rui
R
D000599:Amino Acids, Diamino / Q000138:chemical synthesis* / Q000737:chemistry; D002384:Catalysis; D020650:Combinatorial Chemistry Techniques; D015394:Molecular Structure; D010081:Oxazolone / Q000737:chemistry*; D013237:Stereoisomerism
D000599:Amino Acids, Diamino; D010081:Oxazolone