Transition metal-catalyzed pentannulation of propargyl acetates via styrylcarbene intermediates
Transition metal-catalyzed pentannulation of propargyl acetates via styrylcarbene intermediates
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DOI：
10.1016/j.tet.2007.09.064
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发表时间：
2007-12-03
期刊：
影响因子：
2.1
通讯作者：
Ohe, Kouichi
中科院分区：
文献类型：
--
作者：
Nakanishi, Yusuke;Miki, Koji;Ohe, Kouichi
苯基取代的二、叔丙基酯（末端炔）在铂或钌催化下通过e -乙烯基类羰基中间体生成茚。考虑到戊烷化和环丙化的竞争反应，估计从二丙炔酯和叔丙炔酯中得到E和Z乙烯基类羰基中间体的平衡比分别约为10:90和40:60。在对照实验中，考虑产物的比例，提出了两种反应途径：一类为纳扎罗夫型环化反应，另一类为金属环化反应。(c) 2007 Elsevier Ltd.版权所有。
The indene formation from phenyl-substituted sec- and tert-propargyl esters (terminal alkynes) was achieved by platinum or ruthenium catalysis via E-vinylcarbenoid intermediate. Considering the competitive reactions of pentannulation versus cyclopropanation, the equilibrium ratios of E and Z vinylcarbenoid intermediates from sec- and tert-propargyl esters are estimated at ca. 10:90 and 40:60, respectively. Two reaction pathways, Nazarov-type cyclization and/or metallacycle, from styrylcarbenoid species, are proposed by considering ratios of products in the control experiment. (c) 2007 Elsevier Ltd. All rights reserved.