Zhang Xin, Feng Lei, Tung Chen-Ho, Wang Wenguang
School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, China.
College of Chemistry, Beijing Normal University, Beijing 100875, China.
Inorg Chem. 2023 Nov 13;62(45):18599-18606. doi: 10.1021/acs.inorgchem.3c02911. Epub 2023 Nov 1.
Tautomerization of CH at half-sandwich compound CpFe(1,2-CyPCHS) exclusively produces an iron ethenylidene, CpFe(=C=CH)(1,2-CyPCHS) (). Protonation of the ethenylidene causes nucleophilic attack of the C by sulfur, affording a sulfur-tethered carbene complex, [CpFe=C(CH)SCHPCy] (). This Fischer-type carbene complex undergoes an unusual isomerization by migrating a hydrogen atom from the β-CH group to the α-C, leading to the formation of an olefin complex [CpFe(η-CH=CHSCHPCy] (). Compound also displays diverse redox reactivities. It transforms to a neutral acetylide ferric complex () when reacting with free radical scavengers and to a cationic vinyl complex [Cp*Fe(η-C(=CH)SCHPCy] () upon 1e oxidation. The interconversion between the vinyl and acetylide complexes can be realized through protonation/deprotonation reactions.
在半夹心化合物CpFe(1,2-CyPCHS)中，CH的互变异构仅产生一种乙烯基铁化合物CpFe(=C=CH)(1,2-CyPCHS)（ ）。乙烯基铁化合物的质子化导致硫对C进行亲核进攻，生成一种硫连接的卡宾配合物[CpFe=C(CH)SCHPCy]（ ）。这种费舍尔型卡宾配合物通过将一个氢原子从β-CH基团迁移到α-C上，经历了一种不寻常的异构化过程，导致形成一种烯烃配合物[CpFe(η-CH=CHSCHPCy]（ ）。化合物 还表现出多种氧化还原反应活性。当与自由基清除剂反应时，它会转化为一种中性乙炔铁配合物（ ），在进行1e氧化时会转化为一种阳离子乙烯基配合物[Cp*Fe(η-C(=CH)SCHPCy]（ ）。乙烯基配合物和乙炔配合物之间的相互转化可以通过质子化/去质子化反应实现。
