Bifunctional Phosphine-Enabled Regioselective Cycloisomerization of Enynyl Esters En Route to Bicyclo[2.2.1]heptenes
Bifunctional Phosphine-Enabled Regioselective Cycloisomerization of Enynyl Esters En Route to Bicyclo[2.2.1]heptenes
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双功能膦使烯炔酯区域选择性环异构化为双环[2.2.1]庚烯
DOI：
10.1021/acs.orglett.3c00161
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发表时间：
2023
期刊：
影响因子：
5.2
通讯作者：
Zhang, Liming
中科院分区：
文献类型：
--
作者：
Kohnke, Philip;Zhang, Liming
桥联的烯醇苯甲酸酯是通过串联的金催化的烯炔基酯的环异构化和Diels-Alder反应实现的。金催化允许使用烯炔基底物而不需要额外的丙叉基取代，并实现了较不稳定的环戊二烯酯的高度区域选择性形成。区域选择性由双官能膦配体实现，其远端的苯胺基促进金卡宾中间体的α去质子化。该反应以不同的烯烃取代方式和不同的双烯亲和剂进行。
Expedient access to bridged enol benzoates is realized via a tandem gold-catalyzed cycloisomerization of enynyl esters and the Diels–Alder reaction. The gold catalysis permits the use of enynyl substrates without additional propargylic substitution and achieves the highly regioselective formation of less stable cyclopentadienyl esters. The regioselectivity is enabled by a bifunctional phosphine ligand, the remote aniline group of which facilitates α-deprotonation of a gold carbene intermediate. The reaction works with different alkene substitution patterns and various dienophiles.