Evolution of Propargyl Ethers into Allylgold Cations in the Cyclization of Enynes
作者:Eloísa Jiménez-Núñez、Mihai Raducan、Thorsten Lauterbach、Kian Molawi、César R. Solorio、Antonio M. Echavarren
DOI:10.1002/anie.200902248
日期:2009.8.3
Shifty moves: 1,n‐Enynes with propargyl alcohol, ether, or silyl ether units undergo gold(I)‐catalyzed intramolecular 1,(n−1)‐migration via allylgoldcations (see scheme). These intermediates have been trapped by olefins, indole, and by a formal intramolecular CH insertion. In the case of aryl‐substituted 1,7‐enynes, a cascade process involving a Nazarov‐type cyclization leads to 6,7‐dihydro‐5H‐benzo[c]fluorenes
变动的动作:1,带有炔丙醇,醚或甲硅烷基醚单元的n-烯炔通过烯丙基阳离子经历金(I)催化的分子内1,(n -1)迁移(参见方案)。这些中间体已被烯烃,吲哚和正规的分子内CH插入所俘获。就芳基取代的1,7-炔而言,涉及纳扎罗夫型环化的级联反应会生成6,7-二氢-5 H-苯并[ c ]芴。
α,β-Unsaturated Gold(I) Carbenes by Tandem Cyclization and 1,5-Alkoxy Migration of 1,6-Enynes: Mechanisms and Applications
作者:Pilar Calleja、Óscar Pablo、Beatrice Ranieri、Morgane Gaydou、Anthony Pitaval、María Moreno、Mihai Raducan、Antonio M. Echavarren
DOI:10.1002/chem.201602347
日期:2016.9.12
1,6-Enynes bearing OR groups at the propargyl position generate α,β-unsaturated gold(I)-carbenes/ gold(I) stabilized allyl cations that can be trapped by alkenes to form cyclopropanes or 1,3-diketones to give products of α-alkylation. The best migrating group is p-nitrophenyl ether, which leads to the corresponding products without racemization. Thus, an improved formal synthesis of (+)-schisanwilsonene
在炔丙基位置带有 OR 基团的 1,6-烯炔会生成 α,β-不饱和金 (I)-卡宾/金 (I) 稳定的烯丙基阳离子,这些阳离子可被烯烃捕获以形成环丙烷或 1,3-二酮,从而得到产品α-烷基化。最好的迁移基团是对硝基苯醚,它可以产生相应的产物而不会发生外消旋化。因此,已经完成了(+)-五味子烯A的改进形式合成。不同的竞争反应途径已通过计算描绘出来。
Orthoamide, LXI [1]. Ein neues leistungsfähiges Verfahren zur Synthese von Orthoamid- Derivaten von Alkincarbonsäuren / Orthoamide, LXI [1]. A New, Efficient Procedure for the Synthesis of Orthoamide Derivatives of Alkyne Carboxylic Acids