Symmetry-enforced conformational control of photochemical reactivity in 2-vinyl-1,3-terphenyl
Symmetry-enforced conformational control of photochemical reactivity in 2-vinyl-1,3-terphenyl
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DOI：
10.1021/ja028251q
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发表时间：
2002-11-20
影响因子：
15
通讯作者：
Rubin, M
中科院分区：
文献类型：
--
作者：
Lewis, FD;Zuo, XB;Rubin, M
邻乙烯基联苯光环合成9，10-二氢菲的量子产率很低，这是因为反应的共旋体的基态布居很低。2-乙烯基-1，3-三联苯以单一旋光异构体的形式存在，可进行高效的光环化反应。在77K的刚性玻璃中照射可以观察到8a，9-二氢菲，当玻璃升温时，它会重排为9，10-二氢菲。光环化和热致Sigmatrotic氢移的势垒都非常小。
The photocyclization ofo-vinylbiphenyl to 9,10-dihydrophenanthrene occurs with very low quantum yield because of the low ground-state population of the reactive syn rotamer. 2-Vinyl-1,3-terphenyl exists as a single rotamer which undergoes highly efficient photocyclization. Irradiation at 77 K in a rigid glass permits observation of the 8a,9-dihydrophenanthrene which rearranges to the 9,10-dihydrophenanthrene upon warming of the glass. The barriers for photocyclization and the thermal sigmatropic hydrogen shift are both remarkably small.