Rhodium-Catalyzed Acylation of Vinylsilanes with Acid Anhydrides
作者:Motoki Yamane、Kazuyoshi Uera、Koichi Narasaka
DOI:10.1246/bcsj.78.477
日期:2005.3
A catalytic acylation of vinylsilane with acid anhydride is accomplished by the use of [RhCl(CO)2]2, in which the transmetalation between vinylsilane and rhodium(I) carbonyl complex plays a key rol...
titanium enolates of α-seleno esters in the presence of Ph3P or Ph3PO gave the products with high stereoselectivity favoring the syn isomers. Reaction of α-seleno ketones with TiCl4 in the presence of 2 equiv. of Et3N, and subsequently with aldehydes, gave the aldol products with high syn selectivity. The stereoselectivity in the aldol reaction of 3-pentanone also increased by using an excess amount of Et3N
Rhodium-Catalyzed Acylation of Vinylsilanes with Acid Anhydrides: Application to the Transformation of α-Acyloxy Vinylsilanes to Unsymmetrical 1,2-Diketones
作者:Motoki Yamane、Kazuyoshi Uera、Koichi Narasaka
DOI:10.1246/cl.2004.424
日期:2004.4
Acylation of vinylsilanes with acid anhydrides is catalyzed by [RhCl(CO)2]2 to give α,β-unsaturated ketones. The application of this catalytic system to the acylation of α-acyloxy vinylsilanes affords α-acyloxy enones in good yields, which are converted to unsymmetrical 1,2-diketones or their mono acetals.
Unusual Gold(I)-Catalyzed Isomerization of 3-Hydroxylated 1,5-Enynes: Highly Substrate-Dependent Reaction Manifolds
作者:Fabien Gagosz
DOI:10.1021/ol051397k
日期:2005.9.1
[reaction: see text] The gold(I) isomerization of diversely substituted 3-hydroxylated enynes has led to the discovery of three new unreported skeletal rearrangements furnishing structures such as alkylidene-cyclopentenes, cyclohexadienes or alpha,beta-unsaturated aldehydes under very mild conditions.
We report herein the facile and practical construction of α,β-unsaturatedketones via rhodium-catalyzed direct acylation of vinylsilanes with readily available and abundant carboxylic acids. This protocol features access to a diverse array of synthetically useful functionalities with moderate to excellent yields. More importantly, the late-stage functionalization of pharmaceuticals was also realized