Enol Ester Intermediate Induced Metal-Free Oxidative Coupling of Carboxylic Acids and Arylboronic Acids

摘要

A facile, efficient and environmentally friendly methodology for the preparation of phenolic esters is realized via metal-free coupling of carboxylic acids and arylboronic acids. This sequential one pot reaction, employing methyl propiolate as an activating reagent, proceeds through the formation of enol ester intermediate, followed by a nucleophilic attack on the C-O bond under the oxidation of hydrogen peroxide. These studies display that enol esters, despite previously being overlooked as synthetic intermediates, would be the valuable building blocks for developing carbon-carbon and carbon-heteroatom bond-forming reactions.