Radical Reactions of N-Heterocyclic Carbene Boranes with Organic Nitriles: Cyanation of NHC-Boranes and Reductive Decyanation of Malononitriles

J Am Chem Soc. 2015 Jul 8;137(26):8617-22. doi: 10.1021/jacs.5b04677. Epub 2015 Jun 23.

Abstract

The observation that NHC-boryl radicals abstract cyano groups from various organic nitriles has been parlayed into two complementary transformations. In the main group chemistry aspect, reactions of various NHC-boranes with simple organic dinitriles selectively provide stable NHC-boryl mono- or dinitriles, depending on the nitrile source. In the organic synthesis aspect, reaction of malononitriles and related derivatives with readily available 1,3-dimethylimidazol-2-ylidene borane provides reductively decyanated products in good yields.