Synlett 2024; 35(09): 941-951
DOI: 10.1055/a-2188-1842
account
Chemical Synthesis and Catalysis in Germany

Skeletal Rearrangements Involving Cyclopropyl- and Alkene-Stabilized Silylium Ions

Peng-Wei Long
,
Tao He
,
,
The work was funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany’s Excellence Strategy (EXC 2008/1-390540038). P.-W.L. thanks the China Scholarship Council for a predoctoral fellowship (2019–2023). M.O. is indebted to the Einstein Foundation Berlin for an endowed professorship.


Abstract

This Account summarizes the fascinating chemistry of cyclopropyl-stabilized silylium ions, which are readily available from vinylcyclopropanes (VCPs). Depending on the nucleophilic partner, these reactive intermediates undergo direct ring opening or ring expansion to nonclassical alkene-stabilized silylium ions. The latter can also be accessed by gold as well as proton electrophiles from silicon compounds containing unsaturated C–C bonds. All these reaction cascades can be terminated by C–H or C–C as well as Si–O bond formation. From this, a clearer picture of the versatility of these rather complex chemistries emerges.

1 Introduction

2 Skeletal Rearrangements of Vinylcyclopropanes Involving Cyclopropyl-Stabilized Silylium Ions

2.1 Termination by C–H Bond Formation

2.2 Termination by C–C Bond Formation

3 Related Bond Reorganizations Involving Alkene-Stabilized Silylium Ions

3.1 Initiation by Cationic Gold(I) Complexes

3.2 Initiation by Brønsted Acids

4 Conclusion



Publication History

Received: 07 September 2023

Accepted after revision: 09 October 2023

Accepted Manuscript online:
09 October 2023

Article published online:
23 November 2023

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