期刊
JOURNAL OF ORGANIC CHEMISTRY
卷 69, 期 24, 页码 8445-8450出版社
AMER CHEMICAL SOC
DOI: 10.1021/jo048702k
关键词
-
An efficient method for the cocyclotrimerization of bicyclic alkenes and benzynes catalyzed by palladium phosphine complexes to give the corresponding norbornane anellated 9,10-dihydrophenanthrene derivatives is described. Bicyclic alkenes 1a-i undergo [2 + 2 + 2] cocyclotrimerization with benzynes generated from precursors 2a-d [2-(trimethylsilyl)phenyl triflate (2a), 4,5-dimethyl-2-(trimethylsilyl)phenyl triflate (2b), 6-(trimethylsilyl)-2,3-dihydro-1H-5-indenyl triflate (2c), 4-methyl-2-(trimethylsilyl)phenyl triflate (2d)] in the presence of PdCl2(PPh3)(2) in acetonitrile at ambient temperature to yield anellated 9,10-dihydrophenanthrene products 3a-r in moderate to excellent yields. The [2 + 2 + 2] cocyclotrimerization products from oxa- and azabicyclic alkenes can be applied for the synthesis of polyaromatics, substituted benzo[b]triphenylenes (8a-f), via a simple Lewis acid mediated deoxyaromatization in good yields. In addition the [2 + 2 + 2] products undergo retro Diels-Alder reaction readily, providing a new method for the synthesis of substituted phenanthrenes and for generating isobenzofurans. A plausible mechanism is proposed to account for the catalytic [2 + 2 + 2] cycloaddition reaction.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据