Formation of silazirconacyclopentenes from zirconium-silene complex and alkynes and their reactivities.
During the course of our study on the formation of a complex having a zirconium-silicon bond, we found that zirconium-silene complex 7 was formed from Cp2ZrCl2 and Me2PhSiLi. In the presence of alkyne, diarylalkyne reacted with silene coordinated with zirconium to give silazirconacyclopentene 8. On the other hand, dialkylalkyne inserted into a zirconium-silene complex gave silazirconacyclopentene 9. Hydrolysis of 8 or 9 afforded vinylsilane 13 or allylsilane 16. Transmetalation of zirconacycle 8 into copper in the presence of allyl halide gave a bis-allylated compound in high yield, indicating that alkylation occurred on the alkyne carbon and the methyl group of silicon. From bis-allylated compounds, eight-membered ring compounds having silicon were obtained in high yield using olefin metathesis.
Kuroda
S
S
Graduate School of Pharmaceutical Sciences, Hokkaido University, Sapporo 060-0812, Japan.
Dekura
F
F
Sato
Y
Y
Mori
M
M