Chinese Journal of Organic Chemistry ›› 2025, Vol. 45 ›› Issue (8): 2938-2944.DOI: 10.6023/cjoc202501003 Previous Articles     Next Articles

ARTICLES

钯催化硅环开环/交叉偶联反应机理研究

李金霞a,*(), 邓远程a, 李嘉瑜a, 郭益豪a, 王广凤a, 段阿冰c,*(), 瞿双林b,*()   

  1. a 长治医学院药学院 药物分子设计与新制剂长治市重点实验室 山西长治 046100
    b 湖南大学化学化工学院 长沙 410082
    c 湖南大学环境科学与工程学院 长沙 410082
  • 收稿日期:2025-01-04 修回日期:2025-03-12 发布日期:2025-03-31
  • 基金资助:
    湖南省青年人才(2021RC3053); 湖南省青年人才(2024RC3077); 上海市手性药物分子工程重点实验室(SMECD2024003); 长沙市自然科学基金(kq2402056); 山西省高等学校科技创新计划(2024L284); 及长治医学院博士科研启动基金(2024BS02)

Mechanistic Study of Palladium-Catalyzed Ring-Opening/Cross-Coupling Reactions of Silacycles

Jinxia Lia,*(), Yuancheng Denga, Jiayu Lia, Yihao Guoa, Guangfeng Wanga, Abing Duanc,*(), Shuanglin Qub,*()   

  1. a Changzhi Key Laboratory of Drug Molecular Design and Innovative Pharmaceutics, School of Pharmacy, Changzhi Medical College, Changzhi, Shanxi 046000
    b College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082
    c College of Environmental Science and Engineering, Hunan University, Changsha 410082
  • Received:2025-01-04 Revised:2025-03-12 Published:2025-03-31
  • Contact: *E-mail:squ@hnu.edu.cn;duanabing@hnu.edu.cn;lijinxia@hnu.edu.cn
  • Supported by:
    Hunan Youth Talent(2021RC3053); Hunan Youth Talent(2024RC3077); Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs(SMECD2024003); Natural Science Foundation of Changsha City(kq2402056); Science and Technology Innovation Project of Shanxi Province(2024L284); Doctoral Startup Foundation of Changzhi Medical College(2024BS02)

Density functional theory (DFT) calculations are employed to investigate the mechanism of the Pd-catalyzed ring-opening/cross-coupling reactions of silacyclobutane and silacyclopentane, as well as the solvent effects. Computational results reveal that the two proposed reaction pathways have relatively high energy barriers. Consequently, an energetically reasonable pathway is suggested. Initially, the Pd(0) species undergoes C—Br bond oxidative addition, forming a Pd(II)-Br species. Following this, due to their distinct ring strains, the ring opening modes of the silacyclobutane and silacyclopentane systems are different. In the silacyclobutane system, the Pd(II)-Br species undergoes C—Si bond oxidative addition and the Si—Br bond reductive elimination, forming a seven-membered ring Pd(II) species. In contrast, in the silacyclopentane system, the Si atom coordinates with Br⁻ to form a five-coordinated silicon center, which then undergoes SN2-type transmetalation, generating an eight-membered ring Pd(II) species. Finally, the resulting Pd(II) species undergoes C—C bond reductive elimination, Si—Br bond oxidative addition, and etherification, producing sila-tetralins and sila-benzosuberanes. A comparison of solvents with varying polarities shows that adding N,N-dimethylacetamide (DMF) increases the polarity of the silacyclopentane system and lowers the energy of the SN2-type transmetalation, thereby facilitating the ring-opening of silacyclopentane.

Key words: silacyclobutane, silacyclopentane, cross-coupling reaction, density functional theory calculation, SN2-type transmetalation