Sulfur-Enabled Dehydrogenative Transformation of Phenylacetonitriles to α-Iminonitriles with Aliphatic Amines

Herein, we disclose an efficient synthesis of α-iminonitriles facilitated by elemental sulfur through the dehydrogenative transformation of phenylacetonitriles with aliphatic amines. This useful strategy for α-iminonitriles operates at low temperature with a broader substrate scope, furnishing synthetically useful compounds in very good to excellent yields. Mechanistic investigations and observations from the literature suggest that the reaction proceeds via a dehydrogenative dithiolation sequence. Gram-scale synthesis and further synthetic transformation demonstrate the synthetic efficacy and utility of the developed protocol.