Reactions of 2-ethyl-5-methylcyclopenta[b]thienyllithium (thiopentalenyllithium) (2) with various electrophilic reagents afford σ-element-substituted thiopentalenes. However, the reaction with Ph3SnCl yields only one of two possible isomers,viz, triphenyl(4H-cyclopenta[b] thiophen-4-yl)stannane (4c), whereas the reactions with Me3SiCl, Me3SiCl, or Ph2PCl give both possible isomers,viz., trimethyl(
2-乙基-5-
甲基环戊二烯基锂(
硫戊烯基
锂)(2) 与各种亲电试剂反应生成 σ 元素取代的
硫戊烯。然而,与 Ph3SnCl 的反应仅产生两种可能的异构体之一,即三苯基(4H-环戊基 [b]
噻吩-4-基)
锡烷 (4c),而与 Me3SiCl、Me3SiCl 或 Ph2PCl 的反应产生两种可能的异构体,即,三甲基(6H-环戊基[b]
噻吩-6-基)
硅烷(3a)和三甲基(4H-环戊基[b]
噻吩-4-基)
硅烷(4a),三甲基(6H-环戊基[b]
噻吩) -6-基)
锡烷(3b)和三甲基(4H-环戊基[b]
噻吩-4-基)
锡烷(4b),或二苯基(6H-环戊基[b]
噻吩-6-基)膦(3d)和二苯基(4H-
环戊二烯[b]
噻吩-4-基)膦(4d)的比例分别为1∶2、1∶2或1∶1。通过X射线衍射分析确定了化合物4c的结构。