Lewis acid-mediated intramolecular addition of silyl enol ethers to internal unactivated alkynes
作者:Ken-ichiro Imamura、Eiji Yoshikawa、Vladimir Gevorgyan、Tomoko Sudo、Naoki Asao、Yoshinori Yamamoto
DOI:10.1139/v01-134
日期:2001.11.1
The EtAlCl2-mediated intramolecular addition of silyl enol ethers to both terminal and internal unactivated alkynes, bearing alkyl and phenyl susbstituents at the alkyne moiety, gave mono- and bicyclic β,γ-unsaturated ketones in good to excellent yields. On the other hand, the silyloxy-substituted cyclic vinylsilanes were obtained in moderate to high yields when the reactions were catalyzed by B(C6F5)3
EtAlCl2 介导的将甲硅烷基烯醇醚分子内加成到末端和内部未活化的炔烃上,在炔烃部分带有烷基和苯基取代基,得到单环和双环 β,γ-不饱和酮,收率良好至极好。另一方面,当反应在三乙基硅烷的存在下由 B(C6F5)3 催化时,以中等至高产率获得甲硅烷氧基取代的环状乙烯基硅烷。所有反应都完全通过内方式进行。提出了这些区域特异性路易斯酸辅助碳环化的机理。关键词:路易斯酸,甲硅烷基烯醇醚,碳环化,炔烃。