Carboxylic acid addition to terminal alkynes utilizing ammonium tagged Hoveyda-Grubbs catalyst supported on magnetically separable core/shell silica: A highly reusable and air compatible catalytic system
作者:Bengi Özgün Öztürk、Didar Gürcü、Solmaz Karabulut Şehitoğlu
DOI:10.1016/j.jorganchem.2019.01.005
日期:2019.3
core/shell silica gel was tested on carboxylicacid addition reactions to terminal alkynes using a variety of carboxylicacidderivatives under air atmosphere. The catalytic system was found to be compatible with air atmosphere and can tolerate even non-degassed solvents. The reaction parameters such as temperature, substrate/catalyst ratio and the effect of carboxylicacid on the selectivity and yield of
Steric Control at the Wingtip of a Bis-N-Heterocyclic Carbene Ligand: Coordination Behavior and Catalytic Responses of Its Ruthenium Compounds
作者:Sayantani Saha、Tapas Ghatak、Biswajit Saha、Henri Doucet、Jitendra K. Bera
DOI:10.1021/om300469n
日期:2012.8.13
crystallization in air, where both ligands show normal C2/C2 coordination. Thus, the resulting complexes exhibit different structural and electronic characteristics, which are further reflected in their catalytic responses. The catalytic utilities of both compounds toward carboxylic acid addition onto terminal alkyne are evaluated in this work. The abnormally bound 1 shows higher activity and better selectivity
将亚甲基连接的双-NHC配体的N-取代基从正丁基改变为庞大的均二甲苯基使配体配位从正常/正常模式转变为正常/异常模式。均三级翼尖基团提供[Ru II(Mes NHC(CH 2)NHC Mes)(Mes NHC(CH 2)a NHC Mes)(CH 3 CN)2 ] [PF 6 ] 2(1),其中一个是配体表现出混合的C 2 / C 4与相同金属的结合,而第二个配体利用C 2 / C 2用于金属配位的碳。相反,正丁基类似物导致金属氧化,在空气中结晶时会提供Ru III络合物[Ru(n Bu NHC(CH 2)NHC n Bu)2 Cl 2 ] [PF 6 ](2)。两种配体均显示正常的C 2 / C 2配位。因此,所得的配合物表现出不同的结构和电子特性,这进一步反映在它们的催化反应中。在这项工作中,评估了这两种化合物对羧酸加成至末端炔烃的催化作用。异常绑定图1显示了与所有正常对应物2相比更高的活性和更好的选择性。