Dehydroalkylative Activation of CNN- and PNN-Pincer Ruthenium Catalysts for Ester Hydrogenation
作者:Tianyi He、John C. Buttner、Eamon F. Reynolds、John Pham、Jack C. Malek、Jason M. Keith、Anthony R. Chianese
DOI:10.1021/jacs.9b09326
日期:2019.10.30
release is concomitant with the onset of catalysis. A new PNN-pincer ruthenium(0)-imine complex is a highly active catalyst for ester hydrogenation at room temperature, giving up to 15,500 turnovers with no added base. This complex was shown to react reversibly at room temperature with two equivalents of hydrogen to give a ruthenium(II)-dihydride complex, where the imine functionality has been hydrogenated
Selective α‐Deuteration of Cinnamonitriles using D
<sub>2</sub>
O as Deuterium Source
作者:Beibei Guo、Johannes G. Vries、Edwin Otten
DOI:10.1002/adsc.202101093
日期:2022.1.4
The selective α-deuteration of α,β-unsaturated nitriles using the strong base tBuOK or a metal-ligand cooperative Ru pincer catalyst is described. With D2O as deuteriumsource and glyme as solvent at 70 °C, tBuOK is an efficient catalyst for deuteration at the α-C(sp2) position of cinnamonitriles, providing access to a broad range of deuterated derivatives in good to excellent yields and with very
描述了使用强碱t BuOK 或金属-配体协同 Ru 钳形催化剂对 α,β-不饱和腈进行选择性 α-氘化。在 70 °C 下以 D 2 O 作为氘源和甘醇二甲醚作为溶剂,t BuOK 是一种有效的肉桂腈α-C( sp 2 ) 位氘化催化剂,可提供从良好到优异的各种氘化衍生物产率和非常高的氘掺入水平。虽然tBuOK 催化的协议不容忍碱敏感的官能团,使用 Milstein 的钌 PNN 钳形催化剂以优异的产率氘化含有苄基溴或酯部分的肉桂腈衍生物。此外,发现金属-配体协同 Ru 催化剂的 H/D 交换活性显着高于t BuOK,即使在室温下也能很好地进行反应。提出了一种机制建议,当使用t BuOK 作为催化剂时,肉桂腈 α-CH 位置的去质子化,而与 Ru PNN 钳子的 H/D 交换催化可能通过(可逆的)Oxa-Michael 加成 D 2 O 进行。
Selective Room-Temperature Hydrogenation of Amides to Amines and Alcohols Catalyzed by a Ruthenium Pincer Complex and Mechanistic Insight
We report a room-temperature protocol for the hydrogenation of various amides to produce amines and alcohols. Compared with most previous reports for this transformation, which use high temperatures (typically, 100–200 °C) and H2 pressures (10–100 bar), this system proceeds under extremely mild conditions (RT, 5–10 bar of H2). The hydrogenation is catalyzed by well-defined ruthenium-PNNH pincer complexes
我们报告了一种室温协议,用于氢化各种酰胺以产生胺和醇。与以前的大多数此转换报告相比,该报告使用高温(通常为100–200°C)和H 2压力(10–100 bar),该系统在极其温和的条件下(RT,5–10 bar H 2)运行。)。明确定义的钌-PNNH钳形配合物(0.5摩尔%)具有潜在的金属-配体双作用模式催化氢化。形成了不寻常的氨基甲酸钌配合物,并进行了晶体学表征。机理研究表明,室温氢化主要通过Ru-N酰胺/胺金属-配体的配合进行。
Dehydrogenative coupling of alcohols to esters on a silica polyamine composite by immobilized PNN and PONOP pincer complexes of ruthenium
作者:Md Abdul Goni、Edward Rosenberg、Roberto Gobetto、Michele Chierotti
DOI:10.1016/j.jorganchem.2017.05.036
日期:2017.9
served as the base to generate the active pincer catalyst on the BP-1 surface. Both immobilized catalysts were recycled for multiple alcohol reaction cycles. Four-step control experiments were carried out using an alcohol and both immobilized systems. The results revealed the heterogeneity of the alcohol catalysis by both BP-1-Ru-PNN and BP-1-Ru-PONOP systems. This study has opened a new catalytic methodology
Metal–ligand cooperative activation of nitriles by a ruthenium complex with a de-aromatized PNN pincer ligand
作者:Linda E. Eijsink、Sébastien C. P. Perdriau、Johannes G. de Vries、Edwin Otten
DOI:10.1039/c6dt02478e
日期:——
The pincercomplex (PNN)RuH(CO), with a de-aromatized pyridine in the ligand backbone, is shown to react with nitriles in a metal–ligand cooperative manner. This leads to the formation of a series of complexes with new Ru–N(nitrile) and C(ligand)–C(nitrile) bonds. The initial nitrile cycloaddition products, the ketimido complexes 3, have a Brønsted basic (nitrile-derived) Ru–N fragment. This is able