Highly Regioselective Cyclotrimerization of 1-Perfluoroalkylenynes Catalyzed by Nickel
摘要:
We report the highly regioselective cyclotrimerization of the 1-perfluoroalkylenynes in the presence of Ni(PPh3)(4). The substituent effects on the reactivity of the enynes were investigated. We also succeeded in the nickel-catalyzed cocyclization of the 1-perfluoroalkylenynes with (trimethylsilyl)acetylene. The possible structures of the intermediates of the cyclotrimerization and the reasons for the observed high regioselectivity were discussed.
reactivity of alkoxycarbonyl- and cyanoenynes in the homo-benzannulation of conjugatedenynes. The introduction of these electron-withdrawing groups enabled us to carry out the benzannulation of 1-substituted enynes as well as 1,2- and 2,4-disubstituted enynes, which have much lower reactivity compared to 2- or 4-monosubstituted enynes. Polysubstituted benzenes were prepared in a highly regioselective manner
Palladium(0)-Catalyzed Cross-Benzannulation between Conjugated Enynes. Reactivity-Controlled Synthesis of Multifunctionalized Benzenes
作者:Shinichi Saito、Osamu Ohmori、Yoshinori Yamamoto
DOI:10.1021/ol006586b
日期:2000.11.1
[GRAPHICS]The synthesis of multifunctionalizbenzenes such as polysubstituted alkoxycarbonyl- or cyanostyrenes was carried out by the regioselective cross-benzannulation between conjugated enynes in the presence of Pd(PPh3)(4).