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.
Asymmetric Morita-Baylis-Hillman Reaction of Arylaldehydes with 2-Cyclohexen-1-one Catalyzed by Chiral Bis(Thio)urea and DABCO
作者:Min Shi、Xu-Guang Liu
DOI:10.1021/ol7028806
日期:2008.3.1
Novel bis(thio)urea organocatalysts were synthesized from axially chiral (R)-(-)-5,5',6,6',7,7',8,8'-octahydro-1,1'-binaphthyl-2,2'-diamine (H-8-BINAM), and their catalytic abilities have been examined in the Morita-Baylis-Hillman reaction of 2-cyclohexen-1-one or 2-cyclopenten-1-one with a wide range of aromatic aldehydes in combination with DABCO. The best result was achieved in the reaction of 3-fluorobenzaldehyde with 2-cyclohexen-1-one to give the desired Morita-Baylis-Hillman product in 79% yield and 88% ee.
Asymmetric Morita–Baylis–Hillman reaction catalyzed by pepsin
Pepsin from porcine gastric mucous shown catalytic promiscuity was first discovered to catalyze the Morita-Baylis-Hillman (MBH) reaction between aromatic aldehydes with 2-cyclohexen-1-one or 2-cyclopenten-i-one in a two-phase medium of phosphate buffer/cyclohexane in the presence of 1,4-diazabicyclo[2.2.2]octane (DABCO). The best results of the corresponding MBH products up to 77% yield and 38% ee were achieved. (C) 2015 Elsevier B.V. All rights reserved.