Stereospecific and Regioselective Isocyanide Insertions into Siliranes and Reactions of the Resulting Iminosilacyclobutanes
作者:Phuc T. Nguyen、Wylie S. Palmer、K. A. Woerpel
DOI:10.1021/jo9816257
日期:1999.3.1
The insertions of p-tolyl and tert-butyl isocyanide into siliranes yielded iminosilacyclobutanes with stereospecific retention of configuration. Monosubstituted siliranes underwent insertion into the more substituted Si-C bond of the ring, although this regioselectivity was eroded as substitution increased on the silirane ring. The iminosilacyclobutane products tautomerized thermally or in the presence of a palladium catalyst to yield the thermodynamically more stable aminosilacyclobutenes. Ring-expansion reactions of iminosilacyclobutanes were promoted by acids: treatment with aqueous copper sulfate produced an oxasilacyclopentane in high yield, whereas with trifluoroacetic acid, oxasilacyclohexanes were formed.