合成了带有吡啶基吡唑基-咪唑基配体的稀有钌(II)配合物,并在82°C或室温下在2-丙醇中的酮转移氢化中表现出极高的催化活性,达到了100%的底物转化率和最终在82°C下使用0.05 mol%的催化剂的TOF可达7.2×10 5 h -1,在室温下使用0.1 mol%的催化剂的TOF可达55 800 h -1。
合成了带有吡啶基吡唑基-咪唑基配体的稀有钌(II)配合物,并在82°C或室温下在2-丙醇中的酮转移氢化中表现出极高的催化活性,达到了100%的底物转化率和最终在82°C下使用0.05 mol%的催化剂的TOF可达7.2×10 5 h -1,在室温下使用0.1 mol%的催化剂的TOF可达55 800 h -1。
Construction of Highly Active Ruthenium(II) NNN Complex Catalysts Bearing a Pyridyl-Supported Pyrazolyl-Imidazolyl Ligand for Transfer Hydrogenation of Ketones
作者:Fanlong Zeng、Zhengkun Yu
DOI:10.1021/om801080p
日期:2009.3.23
A family of hemilabile ruthenium(II) NNN complexes bearing a unsymmetrical 2-(benzoimidazol-2-yl)-6-(pyrazol-l-yl)pyridine ligand has been synthesized and exhibited good to excellent catalytic activity in transfer hydrogenation of ketones in refluxing 2-propanol, reaching final TOFs up to 7.2 x 10(5) h(-1) with 0.05 mol % loading. The gamma-NH effect of the benzoimidazol-2-yl moiety in the ligand and coordination modes of the metal center in a Ru(II) NNN complex has great influence on the catalytic activity of the complex catalyst in transfer hydrogenation of ketones. It has been demonstrated that one of the structural prerequisites for an active Ru(II) complex catalyst is the coordinatively unsaturated environment around the metal center in the complex or the precatalyst, and the catalytic activity of a complex catalyst can be enhanced by making its metal center cationic. This paper presents a methodology to construct new types of efficient Ru(II) complex catalysts for transfer hydrogenation of ketones.