Chiral Hydroxytetraphenylene-Catalyzed Asymmetric Conjugate Addition of Boronic Acids to Enones
作者:Guo-Li Chai、A-Qiang Sun、Dong Zhai、Juan Wang、Wei-Qiao Deng、Henry N. C. Wong、Junbiao Chang
DOI:10.1021/acs.orglett.9b01637
日期:2019.7.5
(S)-2,15-Br2-DHTP-catalyzed asymmetric conjugate addition of boronic acids to β-trifluoromethyl α,β-unsaturated ketones and enones was studied. The reaction afforded the corresponding Michael addition products in moderate to high yields with excellent enantioselectivities (up to 99:1 er). This catalytic system features mild reaction conditions, high efficiency, and tolerance to heteroarylboronic acids
catalysts has been proven to have great advantages in asymmetric catalysis. We constructed two chiral metalla-triangles by highly efficient coordination-driven self-assembly from a chiral 3,3'-dipyridyl substituted BINOL donor. They were successfully applied in asymmetric conjugate addition of a series of α,β-unsaturated ketones with trans-styrylboronic acids. The use of these metalla-triangles as supramolecular
(Thio)urea cocatalyst accelerates O-monoacyltartaric acid (MAT)-catalyzed enantioselective conjugate addition of boronic acid to unsaturated ketone. Kinetic studies of this reaction revealed first-order dependence of each substrate and catalyst and second-order dependence of (thio)urea, leading to reduction of the catalyst loading and development of more active and enantioselective MAT monoaryl ester
(硫代) 脲助催化剂加速 O-单酰基酒石酸 (MAT) 催化硼酸与不饱和酮的对映选择性共轭加成。该反应的动力学研究揭示了每种底物和催化剂的一级依赖性和(硫)脲的二级依赖性,导致催化剂负载量的减少和更具活性和对映选择性的 MAT 单芳基酯催化剂的开发。
Enantioselective conjugate addition of boronic acids to enones catalyzed by O-monoacyltartaric acids
We have found that O-monoacyltartaric acids catalyze asymmetricconjugateaddition of boronicacids to enones with good enantioselectivity, and the 3,5-di(tert-butyl)benzoyl group provides the best results among the acyl groups examined.