Search

Reaction of [Pt(bipy)Cl2] (bipy = 2,2′-bipyridine) with an excess of silver triflate in refluxing acetonitrile readily affords [Pt(bipy)(MeCN)2](CF3SO3)2 as a yellow, crystalline solid. A single crystal X-ray diffraction study shows that the cations are arranged in a zig-zag manner in rows parallel to the b axis of the monoclinic unit cell. Consideration of the crystal structures of related bipyridyl ligand complexes of platinum(II), leads to the conclusion that a stacked structure with intermolecular Pt…Pt interactions for the title compound is prevented by the electrostatic repulsion between adjacent cations that are doubly charged.

Methyl 2-bromomethylprop-2-enoate reacts with benzaldehyde and with salicylaldehyde via its Sn and Zn complexes under aqueous conditions to form α-methylene-γ-lactones in high yields. In the case of salicylaldehyde X-ray analysis proves conclusively formation of a five- rather than a seven-membered ring. Under the above conditions 2-bromomethyl-3-phenylprop-2-enoate does not afford any cyclic products.

The acrylate ester of salicylaldehyde, in the presence of DABCO, affords a crystalline coumarin salt. Formation of this derivative confirms a vital intermediate in the mechanism of the reaction. Salicylaldehyde, suitably protected, reacts with methyl acrylate to afford a novel coumarin not unlike the vasodilator chromonar.