Palladium-catalyzed reactions of cis-1,1-di-tert-butyl-2,3-dimethylsilirane with disubstituted alkynes produced thermally stable silirenes in high yields (81-86%). Alkyl-, aryl-, trimethylsilyl-, and heteroatom-substituted alkynes were employed. The silirenes reacted with phenylacetylene and <3 mol % of PdCl2(PPh3)2 to produce trisubstituted siloles. A common catalytic cycle involving palladasilacyclobutene accounts for both the formation of silirene and the trisubstituted silole. The palladium-catalyzed extrusion of silylene effectively transfers silylene from one strained ring (a silirane) to form another strained ring (a silirene) and represents an unusual metal-mediated process.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Organic Chemistry
- Inorganic Chemistry