A Combined Computational and Experimental Study of Rh-Catalyzed C-H Silylation with Silacyclobutanes: Insights Leading to a More Efficient Catalyst System.
J Am Chem Soc
; 143(9): 3571-3582, 2021 03 10.
Article
em En
| MEDLINE
| ID: mdl-33621095
ABSTRACT
The study of new C-H silylation reagents and reactions remains an important topic. We reported that under Rh catalysis, silacyclobutanes (SCBs) for the first time were able to react with C(sp2)-H and C(sp3)-H bonds, however the underlying reasons for such a new reactivity were not understood. Through this combined computational and experimental study on C-H silylation with SCBs, we not only depict a reaction pathway that fully accounts for the reactivity and all the experimental findings but also streamline a more efficient catalyst that significantly improves the reaction rates and yields. Our key findings include (1) the active catalytic species is a [Rh]-H as opposed to the previously proposed [Rh]-Cl; (2) the [Rh]-H is generated via a reductive elimination/ß-hydride (ß-H) elimination sequence, as opposed to previously proposed endocyclic ß-H elimination; (3) the regio- and enantio-determining steps are identified; (4) and of the same importance, the discretely synthesized [Rh]-H is shown to be a more efficient catalyst. This work suggests that the [Rh]-H/diphosphine system should find further applications in C-H silylations involving SCBs.
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1
Coleções:
01-internacional
Base de dados:
MEDLINE
Tipo de estudo:
Prognostic_studies
Idioma:
En
Ano de publicação:
2021
Tipo de documento:
Article