Intermolecular Coupling of Alkynes with Acrylates by Recyclable Oxide-Supported Ruthenium Catalysts: Formation of Distorted Ruthenium(IV)-oxo Species on Ceria as a Key Precursor of Active Species
A solid ceria-supported ruthenium catalyst (Ru/CeO2) as well as a zirconia-supported ruthenium catalyst (Ru/ZrO2) showed high activities toward the intermolecular coupling of alkynes with acrylates to give the corresponding 1,3-dienes in high yields. The reaction proceeded in the presence of sodium formate and both internal or terminal alkynes and norbornene could be applied for the catalytic systems
固体二氧化铈负载的钌催化剂(Ru / CeO 2)和氧化锆负载的钌催化剂(Ru / ZrO 2)对炔烃与丙烯酸酯的分子间偶联显示出高活性,从而以高收率得到相应的1,3-二烯。反应在甲酸钠的存在下进行,内部或末端炔烃和降冰片烯均可用于催化体系。固体钌催化剂可以循环使用几次,而不会显着降低活性。二氧化铈负载的钌催化剂的FT-IR和X射线吸收精细结构(XAFS)研究表明,二氧化铈上扭曲的钌(IV)-氧代物种在反应的初始阶段就转变为低价钌物种对偶联反应有效。