Pd(PPh3)4/Et2Zn (0.05/4–5 mol-equiv.) in Et2O at reflux, followed by either protonation, iodination or cyanation, provide cis-disubstituted cyclopentanes and pyrrolidines 5, 7 or 9. These tandem reactions, as well as the conversions 5 → 17 or 18 and 20 → 22 show good to excellent regio- and stereocontrol, which is compared to those of Pd-ene ring closures of 1 and 20.
在回流下,在Et 2 O中将Pd(PPh 3)4 / Et 2 Zn(0.05 / 4-5摩尔当量)与乙酰氧基二烯1环化,然后进行质子化,
碘化或
氰化,得到顺式-二取代的
环戊烷和
吡咯烷5,7或9。与1和20的Pd烯闭环反应相比,这些串联反应以及5 → 17或18和20 → 22的转化显示出良好的对区域和立体的控制。