Metal-Free Direct C-H Cyanation of Alkenes.

A metal-free and direct alkene C-H cyanation is described. Directing groups are not required and the mechanism involves electrophilic activation of the alkene by a cyano iodine(III) species generated in situ from a [bis(trifluoroacetoxy)iodo]arene and trimethylsilyl cyanide as the cyanide source. This C-H functionalization can be conducted on gram scale, and for noncyclic 1,1- and 1,2-disubstuted alkenes high stereoselectivity is achieved, thus rendering the method highly valuable.