Heterobimetallic Indenyl Complexes. Mechanism of Cyclotrimerization of Dimethyl Acetylenedicarboxylate (DMAD) Catalyzed by trans-[Cr(CO)3(Heptamethylindenyl)Rh(CO)2 ]
详细信息 查看全文
- 作者：Laura Mantovani ; Alberto Ceccon ; Alessandro Gambaro ; Saverio Santi ; Paolo Ganis ; and Alfonso Venzo
- 刊名：Organometallics
- 出版年：1997
- 出版时间：June 10, 1997
- 年：1997
- 卷：16
- 期：12
- 页码：2682 - 2690
- 全文大小：195K
- 年卷期：v.16,no.12(June 10, 1997)
- ISSN：1520-6041
文摘
The complextrans-[Cr(CO)3(heptamethylindenyl)Rh(CO)2](II) is a very efficient catalystprecursor in the cyclotrimerization reaction of dimethylacetylenedicarboxylate (DMAD) tohexacarbomethoxybenzene. The formation of the "true" catalyst,likely to be the complextrans-[Cr(CO)3-Ind*-Rh(DMAD)2],is the slow step of the reaction and takes place duringthe induction period, the length of which is temperature dependent.After total consumptionof the monomer two organometallic complexes were isolated from theinorganic residue,viz., the catalyst precursor II and the complextrans-[Cr(CO)3-Ind*-Rh(CO)(FADE)](III;FADE = fumaric acid dimethyl ester), which turns out to be active inthe trimerizationreaction as II. The hydrogenation of DMAD to FADE isprobably occurring via C-H bondactivation of the solvent cyclohexane.