KF-Alumina-Mediated Selective Double Michael Additions of Aryl Methyl Ketones: A Facile Entry to the Synthesis of Functionalized Pimelate Esters and Derivatives
作者:Basudeb Basu、Pralay Das、Ismail Hossain
DOI:10.1055/s-2004-831339
日期:——
Here we describe simple and efficient double Michael additions of aromatic and aliphatic methyl ketones to electron deficient alkenes promoted on a surface of KF-alumina. This one-pot procedure provides an easy access to a host of functionalized pimelate esters, which can be subsequently converted in to 3-acylcyclohexanones.
Highly regioselective addition of an ester enolate equivalent to α,β-unsaturated ketones: selective formation of both isomers derived from 1,2- and 1,4-additions using α-stannyl ester with additives
作者:Makoto Yasuda、Yozo Matsukawa、Keishi Okamoto、Toshifumi Sako、Noriko Kitahara、Akio Baba
DOI:10.1039/b004817h
日期:——
The reaction of α-stannyl ester with α,β-unsaturated ketones in the presence of stannous chloride (SnCl2) and chlorosilanes (Me3SiCl or Me2SiCl2) gave 1,2- and 1,4-addition products, respectively.
A strategically novel kinetic resolution of β-substituted olefiniccarboxylicacids is developed by asymmetric bromolactonization using an organocatalyst, 4-tBuPh-tris 1b. The cyclization stage, which provides δ-lactone, is proposed to be operative for discrimination of each enantiomer of carboxylicacids.
通过使用有机催化剂4 - t BuPh-tris 1b进行不对称溴分子内酯化,开发出了具有战略意义的新型β-取代烯烃羧酸动力学拆分方法。提出提供δ-内酯的环化阶段可用于区分羧酸的每种对映体。
α,β-Unsaturated Orthoesters as Michael Acceptors. The Trityl Salt-Catalyzed Michael Reaction of α,β-Unsaturated Orthoesters with Silyl Enol Ethers
作者:Shu Kobayashi、Teruaki Mukaiyama
DOI:10.1246/cl.1987.1183
日期:1987.6.5
In the presence of a catalytic amount of trityl salts, α,β-unsaturated orthoesters react with various silyl enol ethers to afford the corresponding Michael adducts in good yields.
Michael Addition of Ketone Enolates to α,β-Unsaturated Esters or Amides in a One-Pot Procedure: Highly Efficient Effect of Lithium Salt Generated in situ on Organotin Enolate
Michaeladdition of a metal ketone enolate to an a,p-unsaturated ester is thermodynamically disfavored, and thus, isolated metal enolates with an equimolar amount of Lewis acids or additives are usually required. This work describes the methodology of one-pot Michaeladdition from the parent ketones and unsaturated esters to the products directly. The treatment of a parent ketone with sec-butyllithium
金属酮烯醇化物与 a,p-不饱和酯的迈克尔加成在热力学上是不利的,因此,通常需要分离的金属烯醇化物与等摩尔量的路易斯酸或添加剂。这项工作描述了将母体酮和不饱和酯直接添加到产品中的一锅迈克尔加成方法。用仲丁基锂和 Bu 3 SnBr 处理母体酮得到高度配位的锡烯醇化物,它与原位生成的 LiBr 络合。该物质具有反应性,并在分别与 α,β-不饱和酯和酰胺的反应中提供迈克尔加合物、δ-酮酯和酰胺。