A Proton-Responsive Annulated Mesoionic Carbene (MIC) Scaffold on Ir Complex for Proton/Hydride Shuttle: An Experimental and Computational Investigation on Reductive Amination of Aldehyde
作者:Pragati Pandey、Prosenjit Daw、Noor U Din Reshi、Kira R. Ehmann、Markus Hölscher、Walter Leitner、Jitendra K. Bera
DOI:10.1021/acs.organomet.0c00568
日期:2020.11.9
A Cp*Ir(III) complex (1) bearing a proton-responsive hydroxy unit on an annulated imidazo[1,2-a][1,8]naphthyridine based mesoionic carbene scaffold was synthesized by two different syntheticroutes. The molecular structure of 1 revealed an anionic lactam form of the ligand. The acid–base equilibrium between the lactam-lactim tautomers on the ligand scaffold was examined by 1H NMR and UV–vis spectra
通过两种不同的合成途径合成了在环状咪唑并[1,2- a ] [1,8]萘吡啶基介电卡宾骨架上带有质子响应性羟基单元的Cp * Ir(III)配合物(1)。的分子结构1揭示了配体的阴离子内酰胺形式。通过1 H NMR和UV-vis光谱检查了配体支架上内酰胺-内酯互变异构体之间的酸碱平衡。估算内酰胺形式为1的附件-OH基团的p K a,以评估催化剂的质子转移性能。1的催化功效通过使用三种不同的氢源(分子H 2,i PrOH / KO t Bu组合和HCOOH / Et 3 N(5:2)共沸混合物)评估醛的还原胺化反应。发现在三种不同的氢化方法中,HCOOH / Et 3 N(5:2)共沸混合物是最好的。在反应条件下,催化剂1在羰基上化学选择性地氢化亚胺。使用HCOOH / Et 3 N(5:2)共沸混合物将一系列醛还原为相应的仲胺。此外,催化剂1在还原多种N-杂环亚胺衍生物方面显示出高效率。提
Phosphine-Free Manganese Catalyst Enables Selective Transfer Hydrogenation of Nitriles to Primary and Secondary Amines Using Ammonia–Borane
作者:Koushik Sarkar、Kuhali Das、Abhishek Kundu、Debashis Adhikari、Biplab Maji
DOI:10.1021/acscatal.0c05406
日期:2021.3.5
primary and secondary amines by nitrilehydrogenation, employing a borrowing hydrogenation strategy. A class of phosphine-free manganese(I) complexes bearing sulfur side arms catalyzed the reaction under mild reaction conditions, where ammonia–borane is used as the source of hydrogen. The synthetic protocol is chemodivergent, as the final product is either primary or secondary amine, which can be controlled
Manganese(III) Porphyrin‐Catalyzed Dehydrogenation of Alcohols to form Imines, Tertiary Amines and Quinolines
作者:Kobra Azizi、Sedigheh Akrami、Robert Madsen
DOI:10.1002/chem.201900737
日期:2019.5.2
Manganese(III) porphyrin chloride complexes have been developed for the first time as catalysts for the acceptorless dehydrogenative coupling of alcohols and amines. The reaction has been applied to the direct synthesis of imines, tertiary amines and quinolines where only hydrogen gas and/or water are formed as the by‐product(s). The mechanism is believed to involve the formation of a manganese(III) alkoxide
One-pot, chemoselective synthesis of secondary amines from aryl nitriles using a PdPt–Fe<sub>3</sub>O<sub>4</sub> nanoparticle catalyst
作者:Jin Hee Cho、Sangmoon Byun、Ahra Cho、B. Moon Kim
DOI:10.1039/d0cy00630k
日期:——
unsymmetrical secondary amines under mild conditions. However, aryl nitriles containing an electron-donating substituent were rather resistant to the reductive amination, and when hexafluoroisopropanol (HFIP) was used as a co-solvent, the reaction selectivity and yield for unsymmetrical secondary amines increased dramatically. Using the catalyst system, one-pot, gram-scale synthesis of indole was possible
我们已经开发了一种新的催化方法,用于通过PdPt-Fe 3 O 4纳米颗粒(NP)催化剂通过芳基腈与硝基烷烃的还原胺化反应,实现不对称仲胺的一锅级联反应。与单金属Pd–Fe 3 O 4或Pt–Fe 3 O 4相比,双金属催化剂的使用提高了反应性和选择性。NP催化剂。使用这种双金属催化体系,我们成功地在温和条件下合成了各种不对称仲胺。然而,含有给电子取代基的芳基腈相当耐还原胺化,当使用六氟异丙醇(HFIP)作为助溶剂时,不对称仲胺的反应选择性和收率大大提高。使用催化剂体系,可以由2-硝基苯基乙腈一锅克级地合成吲哚。由于Fe 3 O 4载体的磁性,双金属催化剂可以容易地使用外部磁体至少循环四次。
A simple and efficient oxidation of primary and secondary benzylamines to acids using table salt in aqueous medium
作者:Ajay Kishor Kushawaha、Arvind Kumar Jaiswal、Shubham Pandey、Koneni V. Sashidhara
DOI:10.1016/j.tet.2021.132502
日期:2021.11
Herein, we have developed a novel, simple, efficient method for the oxidation of aromatic benzylamines to corresponding acids using common table salt in aqueous medium. Oxidation of benzylamine was achieved by using NaCl (20 mol%) as a catalyst, NaOH (4 equiv) and TBHP (5 equiv) as oxidant, in moderate to good yields (34–84%). Control experiments revealed that in situ generated ClO2− ion is the active