Direct Synthesis of Alkynylstannanes: ZnBr<sub>2</sub>Catalyst for the Reaction of Tributyltin Methoxide and Terminal Alkynes
作者:Kensuke Kiyokawa、Nodoka Tachikake、Makoto Yasuda、Akio Baba
DOI:10.1002/anie.201104208
日期:2011.10.24
Metal hopping: Various alkynylstannanes were synthesized by the directreaction of Bu3SnOMe with terminalalkynes at room temperature in the presence of a ZnBr2 catalyst. Rather than acting as a Lewis acid, ZnBr2 was transmetalated with Bu3SnOMe to give Zn(OMe)2, which is key to the catalytic reaction.
Sonogashira Coupling Using Bulky Palladium-Phenanthryl Imidazolium Carbene Catalysis
作者:Yudao Ma、Chun Song、Wei Jiang、Quansheng Wu、Yong Wang、Xueying Liu、Merritt B. Andrus
DOI:10.1021/ol035147k
日期:2003.9.1
[GRAPHICS]Bulky phenanthracenyl imidazolium-derived carbene ligands were investigated for copper-free Sonogashira coupling with terminal acetylenes. Aryl bromides and iodides gave coupled products in excellent yields from the Pd(PPh3)(2)Cl-2 complex with potassium t-butoxide and 18-crown-6 in THF. A remarkable dependence on the size of the ligand was found. The highest yields were obtained with the bulky 2,9-dicyclohexyl-10-phenanthryl ligand 5.