Cyclohexene sulfide, desulfurization

The kinetics and mechanism of rhenium-catalyzed desulfurization of thiiranes was studied experimentally and by means of computation <2006IC5351>. The oxorhenium dimer MeReO(edt)2 (X), where edt= 1,2-ethanedithiolate, was found to catalyze the transfer of S from thiiranes to triarylphosphines and triarylarsines. In the case of phosphines, catalysis was less effective because they converted the dimer catalyst rapidly to MeReO(edt)PAr3, a less effective catalyst. The rate law for AsArs, which did not transform the catalyst, was v = [thiirane][X] with k = 5.581 mol s at 25°C in CDCI3, for X = cyclohexene sulfide. The value of was 10.0 0.9kcalmoP, while AY was —21 3calK moP. The proposed mechanism is shown in Scheme 6. 

Tetramesityldisilene quantitatively desulfurizes cyclohexene sulfide at room temperature <1993CC1348>. Products with Si-S bonds were obtained from a reaction between cyclohexene sulfide and decamethylsilicocene (Scheme 43) <1989AGE1518>. 

When thermolysis of benzothiepines (71c,d) is carried out in the presence of cyclohexene sulfide in carbon tetrachloride or nitromethane as solvent, the desulfuration products (73c,d) together with an equimolar amount of cyclohexene are produced. This behavior leads to the assumption of S2-species as the primary elimination product of sulfur from the thianorcaradiene intermediate K (see Section 9.03.4.2) (Scheme 12) <90ZN(B)1059>. 

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