Chang Hong-Tai, Jeganmohan Masilamani, Cheng Chien-Hong
Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan.
Org Lett. 2007 Feb 1;9(3):505-8. doi: 10.1021/ol062988t.
[reaction: see text] In this paper, we wish to report the intramolecular [2 + 2 + 2] cocyclotrimerization of nitrilediynes catalyzed by the CoI2(dppe)/Zn system at 80 degrees C in CH3CN. Under these reaction conditions, various highly substituted nitrilediynes having steric conjunction at the alpha and beta positions to a nitrile group and a bulkier substitution at the terminal carbon of alkyne undergo [2 + 2 + 2] cocylotrimerization to afford tetra- and pentacyclic pyridine derivatives in good to excellent yields.
[反应：见正文] 在本文中，我们希望报道在80℃的乙腈中，CoI2(dppe)/Zn体系催化的腈二炔的分子内[2 + 2 + 2]环三聚反应。在这些反应条件下，各种在腈基的α和β位具有空间共轭且在炔烃末端碳上有更庞大取代基的高度取代腈二炔发生[2 + 2 + 2]环三聚反应，以良好至优异的产率得到四环和五环吡啶衍生物。
