Enantioselective conjugate addition of 3-fluoro-oxindoles to vinyl sulfone: an organocatalytic access to chiral 3-fluoro-3-substituted oxindoles
作者:Xiaowei Dou、Yixin Lu
DOI:10.1039/c3ob41267a
日期:——
An organocatalytic conjugate addition of prochiral 3-fluorinated oxindoles to vinyl sulfones was described for the first time. In the presence of bifunctional tertiary amine–thiourea catalysts, 3-fluoro-3-substituted oxindole adducts were obtained in excellent yields and with high enantiomeric excesses.
A catalytic regioselective addition reaction of oxindoles with ynals is developed. Allene-containing derivatives bearing various substituents and substitution patterns are afforded as the products in generally moderate to good yields with moderate diastereoselectivities. Several of allenes obtained from this protocol are valuable in the development of novel bactericides for plant protection.