期刊
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
卷 60, 期 17, 页码 9618-9626出版社
WILEY-V C H VERLAG GMBH
DOI: 10.1002/anie.202015960
关键词
acidity; silanes; silicon; strained molecules; zwitterions
资金
- NoNoMeCat Marie Skodowska-Curie training network - European Union [675020-MSCA-ITN-2015-ETN]
- Netherlands Organization for Scientific Research (NWO)
- SURF Foundation
By introducing strain, a strained cationic silane [TSMPSiH](+) with unusual acidity was successfully prepared, showing correlations with ring strain, inductive and electrostatic effects. The conjugate base TSMPSi can activate a THF molecule in the presence of CH-acids to generate a highly fluxional alkoxysilane.
Compounds of main-group elements such as silicon are attractive candidates for green and inexpensive catalysts. For them to compete with state-of-the-art transition-metal complexes, new reactivity modes must be unlocked and controlled, which can be achieved through strain. Using a tris(2-skatyl)methylphosphonium ([TSMPH3](+)) scaffold, we prepared the strained cationic silane [TSMPSiH](+). In stark contrast with the generally hydridic Si-H bond character, it is acidic with an experimental pK(a)(DMSO) within 4.7-8.1, lower than in phenol, benzoic acid, and the few hydrosilanes with reported pK(a) values. We show that ring strain significantly contributes to this unusual acidity along with inductive and electrostatic effects. The conjugate base, TSMPSi, activates a THF molecule in the presence of CH-acids to generate a highly fluxional alkoxysilane via trace amounts of [TSMPSiH](+) functioning as a strain-release Lewis acid. This reaction involves a formal oxidation-state change from Si-II to Si-IV, presenting intriguing similarities with transition-metal-mediated processes.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据