Iron(II)-catalyzed C-2 cyanomethylation of indoles and pyrroles via direct oxidative cross-dehydrogenative coupling with acetonitrile derivatives

A novel and efficient approach for the C(sp²)-H/C(sp³)-H oxidative coupling of indoles and pyrroles with acetonitrile derivatives was reported by using the Fe(ii) complex as the catalyst. Various substrates were well tolerated in this methodology and the corresponding desired products were given in moderate to good yields. Moreover, the late-stage C-H cyanoalkylation of bioactive molecules was achieved in good yields. Generally, this reaction features excellent functional group compatibility, broad substrate scope and good regioselectivity.