Direct Transformation of <i>N</i>,<i>N</i>-Dimethylformamide to −CN: Pd-Catalyzed Cyanation of Heteroarenes via C–H Functionalization
作者:Shengtao Ding、Ning Jiao
DOI:10.1021/ja204063z
日期:2011.8.17
This paper describes the direct cyanation of indoles and benzofurans employing N,N-dimethylformamide (DMF) as both reagent and solvent. Isotopic labeling experiments indicated that both the N and the C of the cyano group derived from DMF. This transformation offers an alternative method for preparing aryl nitriles, though it is currently limited in scope to indoles and benzofurans.
An unprecedented palladium-catalyzed cyanation of aromatic C-H bonds by using tertiary amine derived isocyanide as a novel cyano source was developed. Cu(TFA)(2) was used as a requisite stoichiometric oxidant. Mechanistic studies suggest that a tertiary carbon cation-based intermediate Is involved following the C-N bond breakage.