Tributylphosphine or dimethylphenylphosphine (1-5 mol%) catalyzed the Morita-Baylis-Hillman reaction of 2-cyclopenten-1-one (1) with 1.2 equivalents of formalin proceeded nicely to give 2-hydroxymethyl-2-cyclopenten-1-one (2) within a short period and in an excellent yield. The efficiency of the reaction (yield and time) was strongly dependent on the solvent and the best result was obtained in the case of an aqueous MeOH-CHCl3 solvent system.
DMAP-catalyzed hydroxymethylation of 2-cyclohexenones in aqueous medium through Baylis-Hillman reaction
作者:Farhat Rezgui、Mohamed Moncef El Gaied
DOI:10.1016/s0040-4039(98)01206-4
日期:1998.8
Reaction of 2-cyclohexenones 1a-d with aqueous formaldehyde, catalyzed by DMAP in THF, affords the corresponding 2-(hydroxymethyl)-2-cyclohexenones 2a-d in good yields. (C) 1998 Elsevier Science Ltd. All rights reserved.
Formal total synthesis of (±)-magellanine
作者:Miyuki Ishizaki、Yuka Niimi、Osamu Hoshino
DOI:10.1016/s0040-4039(03)01516-8
日期:2003.8
Formal total synthesis of magellanine is described. Key features in the synthesis were stereoselective Ireland-Claisen rearrangement and intramolecular Pauson-Khand reaction of exo-cyclic enynes. (C) 2003 Elsevier Ltd. All rights reserved.
A formal total synthesis of Lycopodium alkaloid, (±)-magellanine, by using the intramolecular Pauson Khand reaction
A formaltotalsynthesis of magellanine was accomplished by using the stereoselective Ireland–Claisen rearrangement and the intramolecular Pauson–Khandreaction of exocyclic enynes as key steps.
from 2-cyclohexanones and diverse aldehydes under palladium catalysis, by in situ generation of electron-neutral and HOMO-raised η2-Pd(0)-dienone complexes via an oxidative insertion/π–σ-isomerization/β-H elimination activation sequence. The subsequent umpolung vinylogousaddition to a variety of imines is realized upon Pd(0)-mediated π-Lewis base catalysis, finally furnishing o-cresolylated products
在这里,我们报告了在钯催化下与 Morita- Baylis -Hillman (MBH) 碳酸酯在钯催化下的不对称形式亲核亲核化反应,通过原位产生电子中性和 HOMO 引发的 η 2 -Pd( 0)-二烯酮复合物通过氧化插入/π-σ-异构化/β-H消除激活序列。随后在 Pd(0) 介导的 π-Lewis 碱催化下实现了对各种亚胺的 umpolung 插烯加成,最终提供了o-甲酚化产物,然后是另一个级联的 π-σ-异构化/β-H 消除/芳构化过程。通过采用新设计的庞大的手性亚膦酰胺配体,对大量的底物组装实现了中等至优异的非对映和对映选择性,并且可以轻松地加工所得的多功能产品以获取多种对映体富集的结构。此外,催化反应途径通过对照实验得到了很好的启发。