Synthesis of Symmetrical Poly(pyridin-2-yl)Ethane Ligands

Abstract

Reaction of lithium derivatives of pyridin-2-ylmethanes, (C5H4N)CRR′- Li+, with mercury(II) iodide results in precipitation of mercury, and formation of symmetrical poly(pyridin-2-yl)ethanes [(C5H4N)CRR′]2 (R = H, R = Ph; R = Me, R′ = Ph; R = R′ = Me; R = C5H4N, R′ = H; R = C5H4N, R′ = Me). For [(C5H4N)CRPh]2 (R = H, Me) mixtures of the meso and racemic diastereoisomers were found. Two of the products, [(C5H4N)CHPh]2 and [(C5H4N)2CH]2, were obtained in high yield, and readily form palladium(II) acetate complexes, Pd(O2CMe)2{rac-[(C5H4N)CHPh]2} and [Pd(O2CMe)2]2[(C5H4N)2CH]2. The synthesis of 2-(1-phenylethyl)pyridine and a convenient route to bis(pyridin-2-yl)methane are described.