C,N-chelated organotin(IV) trifluoromethanesulfonates: Synthesis, characterization and preliminary studies of its catalytic activity in the direct synthesis of dimethyl carbonate from methanol and CO2

C,N-chelated tri- and diorganotin(IV) halides react with 1 or 2 mol equiv of silver trifluoromethanesulfonate (triflate, AgOTf, OTf = OSO2CF3−) to give corresponding C,N-chelated organotin(IV) triflates. The triorganotin(IV) triflates of general formula LCNR2SnOTf (R = n-Bu (1), Ph (2)) are presumably more stable towards hydrolysis than the diorganotin(IV) triflates LCNRSn(OTf)2 (R = n-Bu (3), Ph (4)). All prepared organotin(IV) triflates bearing the LCN ligand (where LCN is 2-(N,N-dimethylaminomethyl)phenyl-) were characterized by multinuclear NMR spectroscopy and elemental analysis. In addition, the structure of 3 was determined by the X-ray diffraction analysis. The catalytic activity of 1, 2 and 3 in the direct synthesis of dimethyl carbonate (DMC) from CO2 and methanol was investigated showing promising yield of DMC in the case of reaction promoted by 1.