Study on the copper-mediated cyanation reaction using ammonium iodide and DMF as a cyanide source

Abstract

A new protocol of cyanation reaction using combined cyanide source (N,N-dimethylformamide and ammonium iodide) was developed in our group in 2011. Based on this study, the cyanation reaction of aromatic boronic acids, boronate esters, and borate salts were developed under copper-mediated oxidative conditions using ammonium iodide and DMF for the first time. The procedure was successfully extended to the cyanation of electron-rich benzenes, and regioselective introduction of a cyano group at the arene C-H bonds was also achieved. The observation that the reaction proceeds via a two-step process, initial iodination and then cyanation, led us to propose that ammonium iodide plays a dual role to provide iodide and nitrogen atom of the cyano moiety.