Simulation of HD Reactivity. 1. Competition Rates of Oxidation of HD withSimulants

摘要

The competition rates of oxidation of 14 sulfide simulants relative to HD weredetermined quantitatively in CDC13 to 20 deg C. N-Sulfonyloxaziridine, which selectively oxidized sulfides to the corresponding sulfoxides in less than 2 min, was used as the standard oxidant. The competition rates increased with the nucleophilicity of the sulfur atom. The nucleophilicity of the bivalent sulfur, in turn, was controlled by the electronic effect of the substituent groups in the molecule. Most sulfides examined were more nucleophilic than HD, consisting of two strongly electron-withdrawing 2-chloroethyl groups. The hydrolysis rate of the sulfides determined previously followed the same trend because the rate-determining step was neighboring sulfur-assisted formation of an ethylenesulfonium ion, the stability of which also depends on the same electronic effect of the substituent group. Furthermore, the competition rates were useful in predicting the rate of production of dimeric sulfonium salts from the hydrolysis of 2-chlorethyl sulfides. Keywords: Competition rate; Sulfides, N-sulfonyloxaziridine, Oxidation, Hydrolysis rate, 2-Chloroethyl sulfides, HD, OXA, HD, Sulfoxides. (JG)