Direct Amidation of Carboxylic Acids Catalyzed by <i>ortho</i>-Iodo Arylboronic Acids: Catalyst Optimization, Scope, and Preliminary Mechanistic Study Supporting a Peculiar Halogen Acceleration Effect
作者:Nicolas Gernigon、Raed M. Al-Zoubi、Dennis G. Hall
DOI:10.1021/jo3013258
日期:2012.10.5
synthetic products motivates the development of catalytic, direct amidation methods employing free carboxylic acids and amines that circumvent the need for stoichiometric activation or coupling reagents. ortho-Iodophenylboronic acid 4a has recently been shown to catalyze direct amidation reactions at room temperature in the presence of 4A molecularsieves as dehydrating agent. Herein, the arene core of ortho-iodoarylboronic
Boronic Acid Catalysts and Methods of Use Thereof for Activation and Transformation of Carboxylic Acids
申请人:Hall Dennis
公开号:US20140142322A1
公开(公告)日:2014-05-22
The present application provides methods and catalysts for activation of carboxylic acids for organic reactions. In particular, methods are disclosed for direct nucleophilic addition reactions, such as, amidation reactions with amines, cycloadditions, and conjugate additions, using boronic acid catalysts of formula I, II or III: Also included are novel boronic acid catalysts of formula IV, V and III: