Cobalt-Catalyzed Hydrocyanation of Methylenecyclopropanes to Homoallylic Nitriles.

We describe herein a novel synthesis of various homoallylic nitriles via cobalt-catalyzed hydrocyanation of methylenecyclopropanes. Excellent selectivity, mild reaction conditions, good functional group compatibility, gram-scale reaction, and product transformations demonstrate the power of this protocol. This extraordinary selectivity can probably be attributed to the stronger aptitude of the alkyl-cobalt cyanide intermediate to undergo reductive elimination rather than β-hydride elimination.