S-alkylthiophenium, S-methylbenzo[b]thiophenium) are prepared by alkylation of the corresponding thiophene complexes. The S-alkylthiophenium species are proposed to undergo rapid and reversible cleavage of the C5−S bond, forming highly electrophilic metallacyclopropene intermediates. Although not directly observable, these vinyl cation intermediates may be trapped with both anionic and neutral nucleophiles
[Os(NH3)5(4,5-η2-L)](OTf)3 类型的几种 S-烷基
噻吩配合物(其中 L = S-烷基
噻吩,S-甲基苯并[b]
噻吩)是通过烷基化制备的相应的
噻吩配合物。S-烷基
噻吩鎓物种被提议进行 C5-S 键的快速和可逆裂解,形成高度亲电子的
金属环
丙烯中间体。虽然不能直接观察到,但这些
乙烯基阳离子中间体可以被阴离子和中性亲核试剂捕获,提供 η2-4-(烷
硫基)-
1,3-丁二烯配合物。用氧化剂(例如,
DDQ)处理选定的4-(烷
硫基)-
1,3-丁二烯配合物以良好的收率提供有机
配体。