有机化学 ›› 2015, Vol. 35 ›› Issue (3): 698-704.DOI: 10.6023/cjoc201410023 上一篇    下一篇

研究论文

甲硅烷基(硅烯)钌配合物中甲硅烷基甲氧基化反应机理的理论研究

周莉a, 李阳a, 林芙蓉a, 田迪英a, 雷群芳b, 方文军b, 谢湖均a   

  1. a 浙江工商大学应用化学系 杭州 310018;
    b 浙江大学化学系 杭州 310028
  • 收稿日期:2014-10-16 修回日期:2014-12-10 出版日期:2015-03-25 发布日期:2015-01-05
  • 通讯作者: 谢湖均 E-mail:hujunxie@gmail.com
  • 基金资助:

    国家自然科学基金(No. 21203166)和食品科学与工程浙江省重中之重一级学科开放基金(No. JYTsp2014111)资助项目.

Reaction Mechanism for the Alkoxylation of a Silyl Ligand in the Silyl- (silylene)ruthenium Complex: A Density Functional Theory Study

Zhou Lia, Li Yanga, Lin Furonga, Tian Diyinga, Lei Qunfangb, Fang Wenjunb, Xie Hujuna   

  1. a Department of Applied Chemistry, Zhejiang Gongshang University, Hangzhou 310018;
    b Department of Chemistry, Zhejiang University, Hangzhou 310028
  • Received:2014-10-16 Revised:2014-12-10 Online:2015-03-25 Published:2015-01-05
  • Supported by:

    Project supported by the National Natural Science Foundation of China (No. 21203166) and the Food Science and Engineering of Most Important Discipline of Zhejiang Province (No. JYTsp2014111).

采用密度泛函理论(DFT), 我们研究了甲硅烷基(硅烯)钌配合物Cp*Ru(CO)(=SiMes2)SiMe3与甲醇发生反应的机理. 整个反应机理包含以下四个步骤: (1) Ru=Si双键和甲醇发生1,2加成反应, 随后通过消除Mes2Si(OMe)H生成Cp*Ru(CO)SiMe3; (2)甲硅烷基配体上的甲基以1,2-甲基的迁移方式从硅原子转移到Ru原子上, 并与甲醇发生1,2加成反应, 生成的甲烷脱离后产生Cp*Ru(CO)Si(OMe)Me2; (3)重复步骤(2)两次, 得到甲氧基化的产物Cp*Ru(CO)Si(OMe)3; (4)异腈配位Ru原子后得到最终的产物Cp*Ru(CO)(CNt-Bu)Si(OMe)3. 甲醇和Ru=Si双键的1,2加成是整个反应的决速步骤, 自由能势垒为35.3 kcal/mol. 此外, 还研究了甲硅烷基(锗烯)钌配合物与甲醇的反应机理, 相比硅烯配合物, 锗烯配合物决速步的能垒相对较低, 为31.8 kcal/mol.

关键词: DFT计算, 反应机理, 锗烯配合物, 硅烯配合物

The mechanism for the reaction of a silyl(silylene) ruthenium complex Cp*Ru(CO)(=SiMes2)SiMe3 with methanol was investigated via the density functional theory (DFT) calculations. The mechanism includes four steps. (1) The reaction initiates via the 1,2-addition of methanol to the Ru=Si bond, followed by Mes2Si(OMe)H elimination to give Cp*Ru(CO)SiMe3; (2) A methyl group of the silyl ligand migrates to Ru center via 1,2-Me migration, together with 1,2-addition of methanol, which is followed by the CH4 release to form Cp*Ru(CO)Si(OMe)Me2; (3) Step (2) repeats twice to give the fully alkoxylated product Cp*Ru(CO)Si(OMe)3. (4) Coordination of isonitrile affords final product Cp*Ru(CO)(CNtBu)Si(OMe)3. The first step involving the 1,2-addition of methanol to the Ru=Si double bond is the rate-determining step for the whole reaction with a free energy barrier of 35.3 kcal/mol. The mechanism for the reaction of a silyl(germylene)ruthenium complex with methanol was also considered. The rate-determining step has relatively lower barrier of 31.8 kcal/mol in contrast to the silyl(silylene) ruthenium complex.

Key words: DFT calculation, reaction mechanism, silylene complex, germylene complex