1443019-53-1Relevant articles and documents
Rhodium-catalyzed [6 + 2] cycloaddition of internal alkynes with cycloheptatriene: Catalytic study and DFT calculations of the reaction mechanism
Zhang, Xinrui,Wang, Jingjing,Zhao, Haitao,Zhao, Hui,Wang, Jianhui
supporting information, p. 3529 - 3536 (2013/07/26)
A rhodium-catalyzed [6 + 2] cycloaddition of internal alkynes with cycloheptatriene is described. A series of substituted alkynes were cycloadded to cycloheptatriene through a [6 + 2] addition to give a variety of substituted bicyclic compounds in excellent yields. The optimal catalytic system for these transformations was a [Rh(COD)Cl]2 (5.0 mol %) catalyst in combination with CuI (10 mol %) and PPh3 (10 mol %). The proposed mechanism for this system includes an initial oxidative coupling reaction between the coordinated cycloheptatriene and the internal alkyne, followed by a [1,3]-shift of the Rh metal center and a reductive elimination from the Rh(III)-allyl complex to give the final product. Calculations using a model Rh(I) catalyst were also carried out to further understand this mechanism.
