Generation of Bis(ferrocenyl)silylenes from Siliranes

Yang Pan,Takahiro Sasamori,Shogo Morisako,Shinobu Aoyagi

doi:10.3390/molecules25245917

Yang Pan, Takahiro Sasamori + Show 2 more

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https://doi.org/10.3390/molecules25245917

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Abstract

Divalent silicon species, the so-called silylenes, represent attractive organosilicon building blocks. Isolable stable silylenes remain scarce, and in most hitherto reported examples, the silicon center is stabilized by electron-donating substituents (e.g., heteroatoms such as nitrogen), which results in electronic perturbation. In order to avoid such electronic perturbation, we have been interested in the chemistry of reactive silylenes with carbon-based substituents such as ferrocenyl groups. Due to the presence of a divalent silicon center and the redox-active transition metal iron, ferrocenylsilylenes can be expected to exhibit interesting redox behavior. Herein, we report the design and synthesis of a bis(ferrocenyl)silirane as a precursor for a bis(ferrocenyl)silylene, which could potentially be used as a building block for redox-active organosilicon compounds. It was found that the isolated bis(ferrocenyl)siliranes could be a bottleable precursor for the bis(ferrocenyl)silylene under mild conditions.

Highlights

Silylenes, i.e., divalent silicon analogues of carbenes, represent highly attractive reactive intermediates due to their considerable potential as building blocks for organosilicon compounds [1,2,3,4,5,6,7].There are several examples of stable silylenes, which are usually stabilized thermodynamically by introduction of heteroatom-based substituents such as amino groups
Silylenes can be generated by reduction of a dihalosilane or photolysis of a trisilane [4,7,33]
[44], Reaction which was used in the following reactions without further purification to its lability toward ferrocenyl (Fc) lithium with SiCl

Summary

Introduction

I.e., divalent silicon analogues of carbenes, represent highly attractive reactive intermediates due to their considerable potential as building blocks for organosilicon compounds [1,2,3,4,5,6,7].There are several examples of stable silylenes, which are usually stabilized thermodynamically by introduction of heteroatom-based substituents such as amino groups. Carbon-substituted silylenes, which do not contain a stabilizing electron-donating ligand, are highly reactive due to their considerable electrophilicity on account of their low-lying LUMOs [18,19,20,21,22,23,24]. Such highly reactive silylenes can be stabilized kinetically by sterically demanding substituents and subsequently being isolated under an inert atmosphere [25,26,27,28]. When the substituents on the central silicon atom offer insufficient steric protection, the products from the aforementioned reactions usually afford complex

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