Carboxyl activation via silylthioesterification: one-pot, two-step amidation of carboxylic acids catalyzed by non-metal ammonium salts

• Type of Material: Article
• Authors: Angus A. Lamar, The University of Tulsa; Lanny S Liebeskind, Emory University
• Language: English
• Date: 2015-09-21
• Publisher: Elsevier
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2015 Elsevier Ltd. All rights reserved.
• License: Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International
• Final Published Version (URL): https://doi.org/10.1016/j.tetlet.2015.09.050
• Title of Journal or Parent Work: Tetrahedron Letters
• Volume: 56
• Issue: 44
• Start Page: 6034
• End Page: 6037
• Grant/Funding Information: This work was supported by Grant GM043107, awarded by National Institute of General Medical Sciences, DHHS.
• Keywords: Ammonium salt catalysis; Thioesterification; Thiosilane; Thiol ester; Direct amidation
• Research Categories: Chemistry, Organic

Abstract

The first organo-catalyzed silylthioesterification of a carboxylic acid and a commercially available mercaptoorganosilane results in the in situ production of an O-silylthionoester. Subsequent amine addition forms amides in an operationally simple one-pot procedure without removal of water. The scope and efficiency of these reactions with respect to the catalyst, carboxylic acid, amine, [Si─S] moiety, and solvent are investigated. A number of functionalities are tolerated in the two-step amidation including alkene, alkyne, alkyl and aryl halides, benzylic ethers, and heterocycles with free coordinating sites.