Atom-Economical Palladium Carbon-Catalyzed de Novo Synthesis of Trisubstituted Nicotinonitriles.

A de novo palladium carbon-catalyzed synthesis of trisubstituted nicotinonitriles from easily synthesized homopropagylic or homoallylic aromatic alcohols in the presence of nitriles has been explored. The mechanism proceeds with an interesting generation of a Pd(II)-C palladacycle followed by an oxidative aromatization to generate the pyridine core. The pyridine core is generated with a noteworthy C-C bond cleavage in the case of the substituted nitriles. The moderate yields and easy separation of the products lend a unique importance to this one-pot methodology.