Stereospecific and Regioselective Isocyanide Insertions into Siliranes and Reactions of the Resulting Iminosilacyclobutanes.
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.
Nguyen
Phuc T.
PT
Department of Chemistry, University of California, Irvine, California 92697-2025.
Palmer
Wylie S.
WS
Woerpel
K. A.
KA