An aldol reaction in an aqueous solution between an aldehyde represented by the following formula (I):
R—CHO (I)
(wherein R is a hydrocarbon group which may have an substituent), and a silicon enolate represented by the following formula (II):
(wherein R
1
and R
2
are a hydrogen atom or an aliphatic hydrocarbon group, at least one of them being an aliphatic hydrocarbon group; and
R
3
is a substituent selected from the group consisting of an aliphatic hydrocarbon group, an aromatic hydrocarbon group and a sulfur-containing substituent, wherein R
2
and R
3
may be combined with each other to form a ring) is performed so as to generate diastereoselectivity by using FeCl
3
, which is a low-cost Lewis acid, and a surfactant.
Chemoenzymatic and bienzymaticcascades: We herein present three cascade routes to produce MBH adducts and compare the key advantages and challenges of the chemoenzymatic and bienzymatic methodologies.
Asymmetric Morita–Baylis–Hillman reactions of 2-cyclohexen-1-one catalyzed by chiral biaryl-based bis(thiourea) organocatalysts
作者:Yuki Nakayama、Takashi Gotanda、Katsuji Ito
DOI:10.1016/j.tetlet.2011.09.064
日期:2011.11
Newly-developed bis(thiourea) 1d was found to be an efficient organocatalyst for the Morita-Baylis-Hillman reaction. High enantioselectivities were obtained in the reaction of 2-cyclohexen-1-one with both aromatic aldehydes (up to 84% ee) and aliphatic aldehydes (up to 96% ee). (C) 2011 Elsevier Ltd. 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.