Highly enantioselective synthesis of alpha-stereogenic esters through catalytic asymmetric michael addition of 4-oxo-4-arylbutenoates.
Highly enantioselective Michael addition of 1,3-dicarbonyl compounds and nitromethane to 4-oxo-4-arylbutenoates catalyzed by N,N'-dioxide-Sc(OTf)(3) complexes has been developed. Using 0.5-2 mol % catalyst loading, various alpha-stereogenic esters were obtained regioselectively with excellent yields (up to 97 %) and enantioselectivities (up to >99 % ee). Moreover, the reaction performed well under nearly solvent-free conditions. The products with functional groups are ready for further transformation, which showed the potential value of the catalytic approach. According to the experimental results and previous reports, a plausible working model has been proposed to explain the origin of the activation and the asymmetric induction.
Wang
Zhen
Z
Key Laboratory of Green Chemistry and Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu 610064, PR China.
Chen
Donghui
D
Yang
Zhigang
Z
Bai
Sha
S
Liu
Xiaohua
X
Lin
Lili
L
Feng
Xiaoming
X
D000475:Alkenes / Q000737:chemistry*; D002087:Butyrates / Q000737:chemistry*; D002384:Catalysis; D004952:Esters / Q000138:chemical synthesis*; D008698:Mesylates / Q000737:chemistry; D008968:Molecular Conformation; D015394:Molecular Structure; D012538:Scandium / Q000737:chemistry; D013237:Stereoisomerism
D000475:Alkenes; D002087:Butyrates; D004952:Esters; D008698:Mesylates; C436603:scandium triflate; D012538:Scandium