Unusual Kinetics Induced by Ligands in Rhodium(III)-Catalyzed Dehydrogenative Olefination Reactions
Dandan Lu1, Kongchuan Wu1, Ting-Bin Wen1
1Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005 Fujian, P. R. China.
Abstract:
In this study, we investigate the effects of ligands on C-H activation during rhodium(III)-catalyzed C-H bond olefination reactions using well-defined [CpXRhIII] catalytic systems with three representative CpX (Cp (η5-C5H5), CpCF3 (η5-C5Me4CF3), and Cp* (η5-C5Me5)) ligands. Our results demonstrate that C-H activation as the rate-limiting step is significantly influenced by the steric properties of the CpX ligands. Moreover, we observe a dramatic acceleration of the simple [CpRhIII]-catalyzed C-H olefination reaction with acid coproducts such as HOAc, implying an autocatalytic C-H activation process.
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