496-15-1Relevant articles and documents
Pd/C-Catalyzed transfer hydrogenation ofN-H indoles with trifluoroethanol and tetrahydroxydiboron as the hydrogen source
Zhou, Xiao-Yu,Chen, Xia
supporting information, p. 548 - 551 (2021/02/06)
Under the guidance of the known mechanism of the hydrogenation of indoles and transfer hydrogenation with tetrahydroxydiboron (B2(OH)4), Pd/C catalyzed transfer hydrogenation ofN-H indoles with trifluoroethanol and tetrahydroxydiborane as the hydrogen source has been developed. This provides an efficient strategy and catalytic system for the reduction of un-activatedN-H indoles, andN-H indolines are obtained with good to excellent yields. In addition, a series of the isotopic labelling experiments were carried out to probe the mechanism.
Organometallic Synthesis of Bimetallic Cobalt-Rhodium Nanoparticles in Supported Ionic Liquid Phases (CoxRh100?x@SILP) as Catalysts for the Selective Hydrogenation of Multifunctional Aromatic Substrates
Rengshausen, Simon,Van Stappen, Casey,Levin, Natalia,Tricard, Simon,Luska, Kylie L.,DeBeer, Serena,Chaudret, Bruno,Bordet, Alexis,Leitner, Walter
, (2020/12/22)
The synthesis, characterization, and catalytic properties of bimetallic cobalt-rhodium nanoparticles of defined Co:Rh ratios immobilized in an imidazolium-based supported ionic liquid phase (CoxRh100?x@SILP) are described. Following an organometallic approach, precise control of the Co:Rh ratios is accomplished. Electron microscopy and X-ray absorption spectroscopy confirm the formation of small, well-dispersed, and homogeneously alloyed zero-valent bimetallic nanoparticles in all investigated materials. Benzylideneacetone and various bicyclic heteroaromatics are used as chemical probes to investigate the hydrogenation performances of the CoxRh100?x@SILP materials. The Co:Rh ratio of the nanoparticles is found to have a critical influence on observed activity and selectivity, with clear synergistic effects arising from the combination of the noble metal and its 3d congener. In particular, the ability of CoxRh100?x@SILP catalysts to hydrogenate 6-membered aromatic rings is found to experience a remarkable sharp switch in a narrow composition range between Co25Rh75 (full ring hydrogenation) and Co30Rh70 (no ring hydrogenation).
Palladium-Catalyzed Direct and Specific C-7 Acylation of Indolines with 1,2-Diketones
Xie, Guilin,Zhao, Yuhan,Cai, Changqun,Deng, Guo-Jun,Gong, Hang
supporting information, p. 410 - 415 (2021/01/26)
The indole scaffold is a ubiquitous and useful substructure, and extensive investigations have been conducted to construct the indole framework and/or realize indole modification. Nevertheless, the direct selective functionalization on the benzenoid core must overcome the high activity of the C-3 position and still remains highly challenging. Herein, a palladium-catalyzed direct and specific C-7 acylation of indolines in the presence of an easily removed directing group was developed. This strategy usually is considered as a practical strategy for the preparation of acylated indoles because indoline can be easily converted to indole under oxidation conditions. In particular, our strategy greatly improved the alkacylation yield of indolines for which only an unsatisfactory yield could be achieved in the previous studies. Furthermore, the reaction can be scaled up to gram level in the standard reaction conditions with a much lower palladium loading (1 mol %).
