Modular Pincer-type Pyridylidene Amide Ruthenium(II) Complexes for Efficient Transfer Hydrogenation Catalysis
作者:Philipp Melle、Yanisha Manoharan、Martin Albrecht
DOI:10.1021/acs.inorgchem.8b01895
日期:2018.9.17
A set of bench-stable ruthenium complexes with new N,N,N-tridentate coordinating pincer-type pyridyl-bis(pyridylideneamide) ligands was synthesized in excellent yields, with the pyridylidene amide in meta or in para position (m-PYA and p-PYA, respectively). While complex [Ru(p-PYA)(MeCN)3]2+ is catalytically silent in transfer hydrogenation, its meta isomer [Ru(m-PYA)(MeCN)3]2+ shows considerable activity
合成了一组具有新的N,N,N-三齿配位钳型吡啶基双(吡啶基亚酰胺)配体的长凳稳定钌络合物,吡啶基亚酰胺处于间位或对位(m- PYA和p -PYA)。而复杂的[Ru(p -PYA)(MeCN中)3 ] 2+是在转移氢化催化沉默,其元异构体的[Ru(米-PYA)(MeCN中)3 ] 2+示出了具有转换频率在50%的转化率相当大的活动TOF 50 = 100小时–1。光谱,电化学和晶体学分析表明,与两价的酸性p - PYA类似物相比,两价离子的m- PYA配体的供体性质明显强于化合价化。通过用亚胺(4-甲基吡啶),胺(乙二胺)和膦(PPh 3,dppm,dppe)交换辅助MeCN配体,可以实现进一步的催化剂优化。活性最高的催化剂由m -PYA钳形配体和PPh 3络合物[Ru(m- PYA)(PPh 3)(MeCN)2 ] 2+组成,TOF 50为430 h –1在有氧条件下,在没有氧气的情况下长达4000