Cleavage of Carbene-Stabilized Disilicon

Reaction of carbene-stabilized disilicon L:SiSi:L (L: = :C{N(2,6-Pri2C6H3)CH}2, 1) with BH3·THF results in facile cleavage of the silicon–silicon double bond and the formation of two quite different “push–pull” stabilized products with borane- and carbene-coordinated silylene moieties: 2, containing a parent silylene (:SiH2); and 3, containing a unique three-membered cyclosilylene.