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
Mild and Selective Cobalt‐Catalyzed Chemodivergent Transfer Hydrogenation of Nitriles
作者:Zhihui Shao、Shaomin Fu、Mufeng Wei、Shaolin Zhou、Qiang Liu
DOI:10.1002/anie.201608345
日期:2016.11.14
Herein, we describe a selective cobalt‐catalyzed chemodivergent transferhydrogenation of nitriles to synthesize primary, secondary, and tertiary amines. The solvent effect plays a key role for the selectivity control. The general applicability of this procedure was highlighted by the synthesis of more than 70 amine products bearing various functional groups in high chemoselectivity. Moreover, this
Synthesis of Symmetric and Unsymmetric Secondary Amines from the Ligand-Promoted Ruthenium-Catalyzed Deaminative Coupling Reaction of Primary Amines
作者:Pandula T. Kirinde Arachchige、Hanbin Lee、Chae S. Yi
DOI:10.1021/acs.joc.8b00649
日期:2018.5.4
found to be effective for the direct deaminative coupling of two primaryamines to form secondary amines. The catalyst 1/L1 was highly chemoselective for promoting the coupling of two different primaryamines to afford unsymmetric secondary amines. The analogous coupling of aniline with primaryamines formed aryl-substituted secondary amines. The treatment of aniline-d7 with 4-methoxybenzylamine led to
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
Self-condensation of primaryamines to symmetrically substituted secondary amines could efficiently be promoted by an inexpensive supported copper catalyst, Cu/Al2O3, easily prepared by the reduction of the hydroxide precursor, Cu(OH)x/Al2O3. Various kinds of structurally diverse primaryamines including benzylamine, picolylamine, and aliphatic amine derivatives could selectively be converted into
廉价的负载型铜催化剂Cu / Al 2 O 3可通过还原氢氧化物前体Cu(OH)x / Al 2 O 3轻松制备,从而有效地促进伯胺向对称取代的仲胺的自缩合。各种结构不同的伯胺,包括苄胺, 苦瓜胺,并且脂肪族胺衍生物可以选择性地转化为相应的仲胺,且产率中等至优异,而在Ar或H 2的1 atm中没有任何助催化剂,例如碱和稳定的配体。与Ar中的反应相比,H 2中的反应对所需仲胺的选择性更高。H 2的作用是促进N-烷基亚胺的氢化和稳定活性Cu(0)物种。另外,在Cu / Al 2 O 3的存在下,可以通过伯胺与醇的N-烷基化和醛的还原胺化来有效地合成不对称取代的仲胺。观察到的催化确实是非均质的,并且回收的Cu / Al2 O 3催化剂可再用于自冷凝,而不会显着降低其催化性能。已经提出了涉及伯胺的脱氢和缩合为N-烷基亚胺然后氢化的反应机理,即所谓的“借用氢途径”。