Computational investigation of the nucleophilic reaction between methylthiolate and 4-bromo-3-methylamino-isothiazole 1,1-dioxide

The mechanism for the nucleophilic reaction between methylthiolate and 4-bromo-3-methylamino-isothiazole 1,1-dioxide has been investigated on the basis of ab initio, MP2 and DFT calculations. Comparison of the computational results with the experimental findings led to the proposal of an unusual nucleophilic addition-elimination reaction mechanism proceeding through a 1,5-sigmatropic hydrogen shift.