Bimolecular reactions of tetrakis(trialkylsilyl)disilenes with various reagents

Versatile reaction modes of tetrasilyldisilenes with various reagents have been disclosed. Typically, tetrakis(t-butyl-dimethylsilyl)disilene 1b react s with 1-alkenes and a 1-alkyne having allylic hydrogens to afford the corr esponding ene-addition products, while a reaction of 1b with styrene gives the [2+2] cycloaddition product. In contrast to tetra-t-butyldisilene and t etramesityldisilene, a reaction of 1b with a 1,3-butadiene gives quantitati vely the [4+2] cycloaddition product. In accord with the biradical nature o f disilene as predicted theoretically, tetrasilyldisilene 1b reacts with ha loalkanes to provide the corresponding 2,3-dichlorotetrasilane or 2-alkyl-3 -chlorotetrasilane probably via radical mechanisms. Facile nucleophilic add itions of water, methanol, and methyllithium to Ib are indicative of the hi gh electrophilicity of 1b.