Tricyclic systems which contain silicon and nitrogen heteroatoms in central seven- and eight-membered rings

Abstract

The generation of three tricyclic ring systems which contain both silicon and nitrogen heteroatoms in the central ring are described. Dibenz[ b, e][1,4]azasilepines are formed in the reaction of dichlorosilanes with the lithiation product from o-BrC 6H 4N(CH 3)CH 2C 6H 4Br- o and n-BuLi but the direct reaction products could not be purified. Dibenz[ b, f][1,4]azasilepines are prepared from the fluoride ion induced expansion of a phenazasiline. Dibenz[ c, f][1,5]azasilocines are produced from reaction of ( o-BrCH 2C 6H 4) 2Si(CH 3) 2 with primary amines. Incorporation of dimethylaminopropyl side chains at both silicon and nitrogen heteroatoms is also described.