Fast Olefin Metathesis: Synthesis of 2-Aryloxy-Substituted Hoveyda-Type Complexes and Application in Ring-Closing Metathesis
作者:Pavlo Kos、Roman Savka、Herbert Plenio
DOI:10.1002/adsc.201200956
日期:2013.1.16
donation of the diaryl ether oxygen atoms in complexes 5 and 6 led to rapidly initiating precatalysts. The Ru(II/III) redox potentials of complexes 6 were determined (6a–d: ΔE=0.89–1.08 V). In the crystal structure of 5b two independent molecules were observed in the unit cell, displaying RuO distances of 226.6(4) and 230.5(3) pm. The catalytic performance of complexes 5 and 6 in various ring-closing metathesis
四个1-(4-R-苯氧基)-2-乙烯基苯(R = NMe 2,H,Cl,NO 2)4a,4b,4c和4d与钌络合物[RuCl 2(NHC)(3-苯基茚基)反应)(py)]在质子树脂的存在下导致形成各自的Hoveyda型络合物5a-d NHC = SIMes [1,3-双(2,4,6-三甲基苯基咪唑啉)-2-亚基]}和6a-d NHC = SIPr [1,3-双(2,6-二异丙基苯基咪唑啉)-2-亚基]},产率66-84%。配合物5和6中较低的空间体积和二芳基醚氧原子的供体减少导致快速引发预催化剂。确定了配合物6的Ru(II / III)氧化还原电位(6a–d: ΔE= 0.89–1.08 V)。在5b的晶体结构中,在晶胞中观察到两个独立的分子,显示RuO距离为226.6(4)和230.5(3)pm。研究了配合物5和6在各种闭环复分解(RCM)反应中的催化性能。15-200 ppm之间的催化剂负载量足以形成各自环状产物的>