title: Highly enantioselective catalytic 1,3-dipolar cycloadditions of α-alkyl diazoacetates: efficient synthesis of functionalized 2-pyrazolines.
abstract: Highly enantioselective 1,3-dipolar cycloaddition reactions of α-substituted diazoacetates are accomplished by catalysis of the chiral oxazaborolidinium ion. Functionalized 2-pyrazolines are synthesized in high to excellent enantiomeric ratios (up to >99 : 1). The synthetic utility of 2-pyrazoline was expanded via preparation of 2,4-diamino ester compounds bearing a chiral quaternary carbon center.
authors.affiliation: Western Seoul Center, Korea Basic Science Institute, Seoul 120-140, Korea. gshwang@kbsi.re.kr.
authors.forename: Sung Il
authors.initials: SI
authors.lastname: Lee
authors.forename: Ka Eun
authors.initials: KE
authors.lastname: Kim
authors.forename: Geum-Sook
authors.initials: GS
authors.lastname: Hwang
authors.forename: Do Hyun
authors.initials: DH
authors.lastname: Ryu
mesh_terms: D000085:Acetates / Q000737:chemistry*; D002384:Catalysis; D003500:Cyclization; D003979:Diazonium Compounds / Q000737:chemistry*; D015394:Molecular Structure; D011720:Pyrazoles / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D000085:Acetates; D003979:Diazonium Compounds; D011720:Pyrazoles