Theoretical studies on the pyrolysis of thiocarbonates

Theoretical studies were carried out to investigate the pyrolysis of O-methyl S-alkyl and S-methyl O-alkyl thiocarbonates, where alkyl groups referred to ethyl, isopropyl and t-butyl groups. Eight possible pathways were found, of which three pathways would generate the alkene products. Not only thermal elimination pathways were calculated, other possible mechanisms, such as rearrangements and nucleophilic substitutions, were also considered. MP2/6-31G(d) level was employed to carry out the calculation and the progress of the reactions was followed by the Wiberg bond indices.