Carbenes heavy-atom carbene analogues

The fert-butyl group is known as one of the most effective kinetic protectors and many reactive molecules have been stabilized and even isolated by using this group. For example, the divalent center of silylenes and germylenes, the heavy atom analogues of carbenes, have been shown to be blocked by tcrt-butyl groups. 

Among the heavy atom carbene analogues, the chemistry of silylenes has been covered by two reviews. A first one describes the reactivity of 2,2,5,5-tetrakis(trimethylsilyl) silacyclopentane-l,l-diyl with a focus on mechanistic discussions. The nature of the reactions (radical with haloalkanes, concerted insertion with OH, SiH and SiCl)... 

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