Akinobu Naka, Y. Matsui, Hisayoshi Kobayashi
Mar 1, 2004
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0
Influential Citations
3
Citations
Journal
Organometallics
Abstract
The photolysis of cis- and trans-1,2-dimethyl-1,2-diphenyl-1,2-disilacyclopentane (la,b) was carried out in the presence of isobutene, acetone, and tert-butyl alcohol. Irradiation of la with a low-pressure mercury lamp inthe presence of isobutene in hexane proceeded stereospecifically to give a cis ene-type adduct (2a) and a cis [2 + 2] cycloadduct (3a) in 34% and 8% yields, respectively. Similar irradiation of la with acetone afforded a cis-ene-type adduct (4a) with high stereospecificity and 1-[hydroxymethylphenylsilyl]-3-(methylphenylsilyl)propane (5) in 28% and 15% yields. The photolysis of 1b with isobutene gave a trans [2 + 2] cycloadduct (3b) and the cis ene-type adduct 2a in 20% and 6% yields, respectively. With acetone, 1b afforded compound 5 as the major product. The photolysis of la in the presence of tert-butyl alcohol produced a mixture of cis- and trans-2,3-benzo-1-tert-butoxy-1,4-dimethyl-4-phenyl-1,4-disilacyclohept-2-ene (6a,b) in a 4:1 ratio in 30% combined yield, in addition to a 14% yield of 1-[tert-butoxymethylphenylsilyl]-3-(methylphenylsilyl)propane (7). Similar photolysis of 1b with tert-butyl alcohol gave again a mixture of 6a and 6b in 22% yield, in a 1:4 ratio, along with 7 in 15% yield. The thermolysis of 3a and 3b proceeded stereospecifically to give the respective ene-type products 2a and 2b in quantitative yields. Computational analyses for the formation of the rearranged silenes have also been reported.