Photoisomerization of Persilyl-Substituted Silacyclopropene: Formation of Stable Persilyl-Substituted 1-Silaallene, and Its Reactivity

摘要

Persilyl-Substituted silcyclopropenes, (R_3Si)_2SiC_2(SiMe_3)_2 (1a:R_3Si = ~iPr_3Si, 1b:R_3Si = ~tBu_2MeSi), were photochemically isomerized to l-silaallene derivatives, (R_3Si)_2Si=C=C(SiMe_3)_2 2, at wavelengths longer than 340 nm. These compounds subsequently photoisomerized to acetylene derivatives, (R_3Si)_2(Me_3Si)Si-C(ident to)C-SiMe_3 3, as a final product. The existence of l-silaallene 2 was demonstrated spectrosically as well as by a trapping reaction with water.