Asymmetric α-Regioselective [3 + 2] Annulation of Morita–Baylis–Hillman Carbonates: Construction of Three Contiguous Stereocenters with Vicinal Quaternary Carbon Centers
作者:Xiaochen Tian、Yongxing Zhang、Hao Dong、Weiwu Ren、Yang Wang
DOI:10.1021/acs.joc.2c00582
日期:2022.8.5
spirocyclic oxindole derivatives containing three contiguous stereogenic centers and vicinal all-carbonquaternarychiralcenters. This reaction exhibits a broad substrate scope and excellent functional group tolerance. Excellent yields with high diastereo- and enantioselectivities were obtained in this efficient organocatalytic reaction.
The exocyclic double bond in 4-arylidene-3-substituted-isoxazolin-5-one (I) undergoes addition reactions with Grignard reagents and with benzene in the presence of aluminiumchloride. Treatment of 4-arylazo derivatives of 3-substituted-isoxazolin-5-ones (III) with Grignard reagents does not effect hetero-ring opening and only the carbonyl group of III enters into reaction, followed by elimination of