Chem. J. Chinese Universities ›› 2021, Vol. 42 ›› Issue (8): 2450.doi: 10.7503/cjcu20210107

• Organic Chemistry • Previous Articles     Next Articles

Rhodium⁃catalyzed C—H Alkenylation of Indoles and Vinyltriethoxysilane

LI Pengjie, ZHOU Chunni, WANG Zetian, ZHENG Ziang, ZHANG Yumin, WANG Liang(), XIAO Biao()   

  1. Key Laboratory of Optoelectronic Chemical Materials and Devices,Ministry of Education,School of Chemical and Environmental Engineering,Jianghan University,Wuhan 430056,China
  • Received:2021-02-22 Online:2021-08-10 Published:2021-08-05
  • Contact: WANG Liang E-mail:wangliang@jhun.edu.cn;biaoxiao@jhun.edu.cn
  • Supported by:
    the National Natural Science Foundation of China(21302064);the Natural Science Foundation of Hubei Province, China(2017CFB690)

Abstract:

A Rhodium-catalyzed direct C—H alkenylation of indoles using commercially available vinyltriethoxysilane as the vinylating reagent was developed. When the reaction was catalyzed by [RhCp*Cl22 with Cu(OAc)2 as oxidant in the presence of AgF in 1,2-dichloroethane at 90 ℃, a series of terminal vinylindole derivatives could be obtained in 42% to 88% yields. The kinetic isotopic effect experiment was conducted and a KH/KD value of 5.7 was obtained, which suggested that the C—H bond cleavage was involved in the rate- determining step. The competition experiment between differently substituted indoles indicated that electron-rich indoles were preferentially converted, suggesting that an electrophilic C—H activation process might be involved in this transformation. A possible reaction mechanism, including coordination, C—H bond activation, transmetallization, reductive elimination and oxidantion, was then proposed. Moreover, this synthetic method was successfully applied to the synthesis of δ-carboline derivative.

Key words: Rhodium catalysts, C—H alkenylation, Indole, Vinyltriethoxysilane

CLC Number: 

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