2-[(8-Dimethylaminonaphthalen-1-yl)dimethylsilyl]-N,N,4,4-tetramethyl-1,2,3,3a,4,5-hexahydro-4-sila-5,9b-ethenobenz[e]inde-9-amine. An unexpected by-product from the reaction of 1-lithio-8-dimethylaminonaphthalene with chlorodimethylvinylsilane

Reaction of 1-lithio-8-dimethylaminonaphthalene with chlorodimethylvinylsilane gives the expected vinylsilane 4 in very poor yield in addition to a large quantity of polymeric material. In addition, the polycyclic silane 6 was obtained in 9% yield; complex 6 arises via an intramolecular cycloaddition of the silene intermediate 7.