Reversible Isomerization Between Silacyclopropyl Cation and Cyclic (Alkyl)(Amino)Silylene

Angew Chem Int Ed Engl. 2023 Jan 23;62(4):e202215394. doi: 10.1002/anie.202215394. Epub 2022 Dec 14.

Abstract

A phosphine-stabilized silacyclopropyl cation 2 has been synthesized and fully characterized. Of particular interest, 2 reversibly isomerizes into the corresponding seven-membered cyclic (alkyl)(amino)silylene 3 at room temperature via a formal migratory ethylene insertion into the Si-P bond. Although silylene 3 has not been spectroscopically detected, its transient formation has been evidenced by the isolation of the corresponding disilene dimer 5 as well as by trapping reactions.

Keywords: Isomerization; Silylenes; Silylium Ions; Small Rings; Transition Metal Complexes.