PERISELECTIVITY IN CYCLOADDITIONS TO VINYLMETHYLKETENE AND STRUCTURALLY RELATED VINYLKETENE IMINES
PERISELECTIVITY IN CYCLOADDITIONS TO VINYLMETHYLKETENE AND STRUCTURALLY RELATED VINYLKETENE IMINES
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DOI：
10.1021/jo00391a020
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发表时间：
1987-07-24
影响因子：
3.6
通讯作者：
GIORGIANNI, P
中科院分区：
文献类型：
--
作者：
BARBARO, G;BATTAGLIA, A;GIORGIANNI, P
比较了C-乙烯基甲基乙烯酮和等电子C-乙烯基乙烯酮亚胺的环加成反应中不同电子需求伙伴的异构体分布。在这两种情况下，非常亲电的反应物（TCNE、PTAD）都会通过涉及累积体系的 CC 双键（C= C= X）和相邻的 C-乙烯基取代基的 1, 4-环加成反应产生独特的异构体。使用亲电子性较低的底物（偶氮二羧酸酯、偶氮甲碱、硫酮）或富电子物质（乙烯基醚、炔胺），可通过 1, 4-和 1, 2-过程获得多种环加合物。
The isomer distribution in cycloaddition reactions of C-vinylmethylketene and isoelectronic C-vinylketene imines, with partners of different electronic demand, has been compared. Very electrophilic reactants (TCNE, PTAD) gave, in both cases, a unique isomer, from a 1, 4-cycloaddition involving the CC double bond of the cumulative system (C= C= X) and the adjacent C-vinyl substituent. With less electrophilic substrates (azo-dicarboxylates, azomethines, thioketones) or electron-rich species (vinyl ethers, ynamines), several cycloadducts are obtained, arising from 1, 4-and 1, 2-processes.