Titanium(III)‐Catalyzed Reductive Decyanation of Geminal Dinitriles by a Non‐Free‐Radical Mechanism

A titanium‐catalyzed mono‐decyanation of geminal dinitriles is reported. The reaction proceeds under mild conditions, tolerates numerous functional groups, and can be applied to quaternary malononitriles. A corresponding desulfonylation is demonstrated as well. Mechanistic experiments support a catalyst‐controlled cleavage without the formation of free radicals, which is in sharp contrast to traditional stoichiometric radical decyanations. The involvement of two Ti(III) species in the C−C cleavage is proposed, and the beneficial role of added ZnCl(2) and 2,4,6‐collidine hydrochloride is investigated.