Chiral phosphinothiourea-catalyzed asymmetric Morita–Baylis–Hillman reactions of acrylates with aromatic aldehydes
作者:Kui Yuan、Hong-Liang Song、Yinjun Hu、Xin-Yan Wu
DOI:10.1016/j.tet.2009.07.066
日期:2009.9
chiral bifunctional phosphinothioureas were synthesized and applied to the enantioselective Morita–Baylis–Hillmanreaction of aromaticaldehydes with acrylates. In the presence of 8 mol % of organocatalyst 2e, the Baylis–Hillman adducts were obtained in good enantioselectivities and up to 96% yield under mild reaction conditions.
Cationic chiral surfactant based micelle-guided asymmetric Morita-Baylis-Hillman reaction
作者:Bashir Ahmad Shairgojray、Aijaz Ahmad Dar、Bilal A. Bhat
DOI:10.1016/j.catcom.2016.05.010
日期:2016.8
Cationic chiral surfactant (1R, 2S)-(-)-N-dodecyl-N-methylephedrinium bromide (DMEB) was utilized for the first time in inducing asymmetry to Morita-Baylis-Hillman reaction in aqueous medium. Proton NMR studies carried out to determine the locus of the reaction in micro-heterogeneous micellar environment, were found useful in proposing a plausible model for asymmetric induction. This work demonstrates that under such mild and nonhazardous reactions conditions, the reaction rates increase, good yields are favored and above all reasonable enantiomeric excesses are obtained. (C) 2016 Elsevier B.V. All rights reserved.
Base-promoted regiodivergent allylation of <i>N</i>-acylhydrazones with Morita–Baylis–Hillman carbonates by tuning the catalyst
作者:Fang Sun、Tingrui Yin、Anni Feng、Yong Hu、Chenxia Yu、Tuanjie Li、Changsheng Yao
DOI:10.1039/c9ob00194h
日期:——
A regiodivergent allylation of N-acylhydrazones with Morita-Baylis-Hillman (MBH) carbonates has been developed, providing α- or γ-allylated products in excellent yields by using different catalysts. The nature of the base catalyst plays a pivotal role in controlling the reaction pathway, allowing regiospecific access to diverse allylic substituted target compounds from identical substrates.