LAUSR

Abstract Novel palladium(II) and platinum(II) heterocycles were synthesized based 1,2-bis(3,5-dimethylisoxazol-4-ylmethylsulfanyl)ethane. According to X-ray Crystallographic data in molecule there are two bonds between divalent sulfur atoms and metal atom S-Pd-S to form a five-membered palladacycle in the twist-conformation with trans orientation of isoxazole rings. The syn-anti-isomerization for the palladaheterocycle in the solution is observed. The activation energy ΔH≠, ΔS≠ and rate of reversible syn-anti-isomerization were established by the dynamic 1H NMR method and quantum-chemical calculations. Proposed mechanism of syn-anti-isomerization of palladacycle via an open-chain forms was offered. It was shown that metallaheterocycle - cis-S,S-dichloro 1,2-[di-(3,5-dimethylisoxazol-4-yl)methylsulfanyl]ethane palladium(II) is efficient catalyst in the amination reaction of allyl phenyl ether and Sonogashira reaction.