Abstract
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.