of carboxylic acids. Herein, we reported the development of a palladium-catalyzed highly enantioselective Markovnikov hydroxycarbonylation of vinyl arenes with CO and water. A monodentate phosphoramidite ligand L6 plays vital role in the reaction. The reaction tolerates a range of functional groups, and provides a facile and atom-economical approach to an array of 2-arylpropanoic acids including several
不对称羟基羰基化是合成羧酸的最基本但最具挑战性的方法之一。在此,我们报道了钯催化的乙烯基芳烃与 CO 和水的高度对映选择性马尔可夫尼科夫羟基羰基化的发展。单齿亚磷酰胺配体L6反应中起重要作用。该反应耐受一系列官能团,并为一系列 2-芳基丙酸(包括几种常用的非甾体抗炎药)提供了一种简便且原子经济的方法。该催化体系还使乙烯基芳烃与醇发生不对称马尔科夫尼科夫氢烷氧基羰基化反应,得到 2-芳基丙酸酯。机理研究表明,氢化钯是不可逆的,是区域和对映体决定步骤,而水解/醇解可能是限速步骤。
A recyclable CO surrogate in regioselective alkoxycarbonylation of alkenes: indirect use of carbon dioxide
作者:P. H. Gehrtz、V. Hirschbeck、I. Fleischer
DOI:10.1039/c5cc05012j
日期:——
Herein, we report a Pd-catalysed alkoxycarbonylation of alkenes based on the use of a recyclable CO2reduction product, the crystalline and air-stableN-formylsaccharin, as a CO surrogate.
Reaction of carboxylicacids with alcohols by using an equimolar amount of di-2-thienyl carbonate (2-DTC) in the presence of a catalytic amount of 4-(dimethylamino)pyridine (DMAP) followed by addition of an equimolar amount of iodine proceeded smoothly to afford the corresponding esters and 2(5H)-thiophenone in good to high yields.
Esterification of carboxylic acids with alcohols by using di-2-thienyl carbonate in the presence of a catalytic amount of 4-(dimethylamino)pyridine (DMAP) proceeded smoothly under mild conditions t...
Kinetic Resolution of Racemic α-Arylalkanoic Acids with Achiral Alcohols via the Asymmetric Esterification Using Carboxylic Anhydrides and Acyl-Transfer Catalysts
enantioselective coupling reaction betweenracemic carboxylic acids and a novel nucleophile, bis(alpha-naphthyl)methanol, to give the corresponding esters with high ee's. This protocol was successfully applied to the production of nonracemic nonsteroidal anti-inflammatory drugs from racemiccompounds utilizing the transacylation process to generate the mixed anhydrides from the acid components with the suitable carboxylic
通过使用非手性醇、芳香族或脂肪族羧酸酐和手性酰基转移催化剂对外消旋 α-取代羧酸进行动力学拆分,可以生产多种光学活性羧酸酯。4-甲氧基苯甲酸酐 (PMBA) 或新戊酸酐与改性苯并四甲醚型催化剂 ((S)-β-Np-BTM) 的组合对于促进外消旋羧酸与新型亲核试剂之间的对映选择性偶联反应最有效, 双(α-萘基)甲醇,得到相应的具有高 ee 的酯。