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。