使用镍(0)NHC 配合物实现 C-S、S-H 和 S-S 键的易断裂。

Facile C-S, S-H, and S-S bond cleavage using a nickel(0) NHC complex.

机构信息

Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany.

出版信息

Dalton Trans. 2009 Sep 21(35):7071-9. doi: 10.1039/b907124p. Epub 2009 Jul 17.

PMID:20449150

Abstract

[Ni2(iPr2Im)4(COD)] 1 (iPr2Im = 1,3-di(isopropyl)-imidazol-2-ylidene) reacts at room temperature with the thioethers methyl para-tolyl sulfide, ethyl phenyl sulfide, benzothiophene and dibenzothiophene to afford the C-S bond cleavage products [Ni(iPr2Im)2(4-CH3-C6H4)(SMe)] 2, [Ni(iPr2Im)2(C6H5)(SEt)] 3, [Ni(iPr2Im)2(1,8-benzothiophenylato)] 4 and [Ni(iPr2Im)2(C,S-dibenzothiophenylato)] 5. In contrast to the reaction of thioethers or sulfoxides (reported earlier), no C-S bond cleavage was observed for the reaction of 1 with the sulfones bezothiophene-1,1-dioxide and methyl phenyl sulfone. In those cases the stable compounds [Ni(iPr2Im)2(eta2-2,3-benzothiophene-1,1-dioxide)] 6 and [Ni(iPr2Im)2(eta2-MeSO2C6H5)] 7 with a eta2-coordinated sulfone ligand have been isolated. Compound 6 has been structurally characterized. S-H bond cleavage was observed using 2-methyl-2-propanthiol to afford [Ni(iPr2Im)2(H)(StBu)] 8. The reaction of 1 with disulfides led to the dithiolato complexes [Ni(iPr2Im)2(SR)2] (R = tBu 9, Me 10, Ph 11) by S-S bond scission.

摘要

[Ni2(iPr2Im)4(COD)] 1（iPr2Im = 1,3-二异丙基-咪唑-2-亚基）在室温下与硫醚甲基对甲苯硫醚、乙基苯基硫醚、苯并噻吩和二苯并噻吩反应，生成 C-S 键断裂产物 [Ni(iPr2Im)2(4-CH3-C6H4)(SMe)] 2、[Ni(iPr2Im)2(C6H5)(SEt)] 3、[Ni(iPr2Im)2(1,8-苯并噻吩基)] 4 和 [Ni(iPr2Im)2(C,S-二苯并噻吩基)] 5。与硫醚或亚砜的反应（之前有报道）不同，1 与砜苯并噻吩-1,1-二氧化物和甲基苯基砜反应时没有观察到 C-S 键断裂。在这些情况下，稳定的化合物 [Ni(iPr2Im)2(eta2-2,3-苯并噻吩-1,1-二氧化物)] 6 和 [Ni(iPr2Im)2(eta2-MeSO2C6H5)] 7 与 eta2-配位的砜配体已被分离。化合物 6 的结构已被确定。使用 2-甲基-2-丙硫醇观察到 S-H 键断裂，生成 [Ni(iPr2Im)2(H)(StBu)] 8。1 与二硫化合物反应，通过 S-S 键断裂生成二硫代配合物 [Ni(iPr2Im)2(SR)2]（R = tBu 9、Me 10、Ph 11）。