52648-48-3Relevant academic research and scientific papers
Direct reductive amination of aldehydes with nitroarenes using bio-renewable formic acid as a hydrogen source
Zhang, Qi,Li, Shu-Shuang,Zhu, Ming-Ming,Liu, Yong-Mei,He, He-Yong,Cao, Yong
, p. 2507 - 2513 (2016)
Reductive amination (RA) is one of the most important transformations in organic chemistry. A versatile and sustainable gas-free RA of aldehydes carried out directly with cheaply available nitroarenes using stoichiometric amounts of non-toxic and entirely renewable formic acid (FA) as the terminal reductant is described herein. A single phase rutile titania supported gold (Au/TiO2-R) catalyst is shown to catalyse efficiently this FA-based direct RA in neat water under mild reaction conditions. The broad scope, mild and neutral conditions, together with CO2 and water as environmental harmless byproducts, make this transformation very useful. Moreover, straightforward examples of the direct construction of bioactive heterocyclic compounds containing a benzimidazole motif were achieved through this protocol.
Effect of the ancillary ligand in N-heterocyclic carbene iridium(III) catalyzed N-alkylation of amines with alcohols
Feng, Xinshu,Huang, Ming
, (2021/06/21)
A series of air-stable N-heterocyclic carbene (NHC) Ir(III) complexes (Ir1-6), bearing various combinations of chlorine, pyridine and NHC ligands, were assayed for the N-alkylation of amines with alcohols. It was found that Ir3, with two monodentate 1,3-bis-methyl-imidazolylidene (IMe) ligands, emerged as the most active complex. A large variety of amines and primary alcohols were efficiently converted into mono-N-alkylated amines in 53–96% yields. As a special highlight, for the challenging MeOH, selective N-monomethylation could be achieved using KOH as a base under an air atmosphere. Moreover, this catalytic system was successfully applied to the gram-scale synthesis of some valuable compounds.
Tungsten-Catalyzed Direct N-Alkylation of Anilines with Alcohols
Lan, Xiao-Bing,Ye, Zongren,Yang, Chenhui,Li, Weikang,Liu, Jiahao,Huang, Ming,Liu, Yan,Ke, Zhuofeng
, p. 860 - 865 (2021/01/18)
The implementation of non-noble metals mediated chemistry is a major goal in homogeneous catalysis. Borrowing hydrogen/hydrogen autotransfer (BH/HA) reaction, as a straightforward and sustainable synthetic method, has attracted considerable attention in the development of non-noble metal catalysts. Herein, we report a tungsten-catalyzed N-alkylation reaction of anilines with primary alcohols via BH/HA. This phosphine-free W(phen)(CO)4 (phen=1,10-phenthroline) system was demonstrated as a practical and easily accessible in-situ catalysis for a broad range of amines and alcohols (up to 49 examples, including 16 previously undisclosed products). Notably, this tungsten system can tolerate numerous functional groups, especially the challenging substrates with sterically hindered substituents, or heteroatoms. Mechanistic insights based on experimental and computational studies are also provided.
Ruthenium(ii) complexes with N-heterocyclic carbene-phosphine ligands for theN-alkylation of amines with alcohols
Huang, Ming,Li, Yinwu,Lan, Xiao-Bing,Liu, Jiahao,Zhao, Cunyuan,Liu, Yan,Ke, Zhuofeng
supporting information, p. 3451 - 3461 (2021/05/03)
Metal hydride complexes are key intermediates forN-alkylation of amines with alcohols by the borrowing hydrogen/hydrogen autotransfer (BH/HA) strategy. Reactivity tuning of metal hydride complexes could adjust the dehydrogenation of alcohols and the hydrogenation of imines. Herein we report ruthenium(ii) complexes with hetero-bidentate N-heterocyclic carbene (NHC)-phosphine ligands, which realize smart pathway selection in theN-alkylated reactionviareactivity tuning of [Ru-H] species by hetero-bidentate ligands. In particular, complex6cbwith a phenyl wingtip group and BArF?counter anion, is shown to be one of the most efficient pre-catalysts for this transformation (temperature is as low as 70 °C, neat conditions and catalyst loading is as low as 0.25 mol%). A large variety of (hetero)aromatic amines and primary alcohols were efficiently converted into mono-N-alkylated amines in good to excellent isolated yields. Notably, aliphatic amines, challenging methanol and diamines could also be transformed into the desired products. Detailed control experiments and density functional theory (DFT) calculations provide insights to understand the mechanism and the smart pathway selectionvia[Ru-H] species in this process.
Convenient and Reusable Manganese-Based Nanocatalyst for Amination of Alcohols
Subaramanian, Murugan,Ramar, Palmurukan M.,Sivakumar, Ganesan,Kadam, Ravishankar G.,Petr, Martin,Zboril, Radek,Gawande, Manoj B.,Balaraman, Ekambaram
, p. 4334 - 4341 (2021/08/25)
The development of new sustainable nanocatalytic systems for green chemical synthesis is a growing area in chemical science. Herein, a reusable heterogeneous N-doped graphene-based manganese nanocatalyst (Mn@NrGO) for selective N-alkylation of amines with alcohols is described. Mechanistic studies illustrate that the catalytic reaction follows a domino dehydrogenation-condensation-hydrogenation sequence of alcohols and amines with the formation of water as the sole by-product. The scope of the reaction is extended to the synthesis of pharmaceutically important N-alkylated amine intermediates. The heterogeneous nature of the catalyst made it easy to separate for long-term performance, and the recycling study revealed that the catalyst was robust and retained its activity after several recycling experiments.
Mimicking transition metals in borrowing hydrogen from alcohols
Banik, Ananya,Ahmed, Jasimuddin,Sil, Swagata,Mandal, Swadhin K.
, p. 8353 - 8361 (2021/07/02)
Borrowing hydrogen from alcohols, storing it on a catalyst and subsequent transfer of the hydrogen from the catalyst to anin situgenerated imine is the hallmark of a transition metal mediated catalyticN-alkylation of amines. However, such a borrowing hydrogen mechanism with a transition metal free catalytic system which stores hydrogen molecules in the catalyst backbone is yet to be established. Herein, we demonstrate that a phenalenyl ligand can imitate the role of transition metals in storing and transferring hydrogen molecules leading to borrowing hydrogen mediated alkylation of anilines by alcohols including a wide range of substrate scope. A close inspection of the mechanistic pathway by characterizing several intermediates through various spectroscopic techniques, deuterium labelling experiments, and DFT study concluded that the phenalenyl radical based backbone sequentially adds H+, H˙ and an electron through a dearomatization process which are subsequently used as reducing equivalents to the C-N double bond in a catalytic fashion.
Cooperative catalysis of molybdenum with organocatalysts for distribution of products between amines and imines
Wu, Di,Bu, Qingqing,Guo, Cheng,Dai, Bin,Liu, Ning
, (2021/02/02)
Multi-amino groups and nitrogen donors compound was discovered as an organocatalyst for N-alkylation of alcohols with amines in the presence of Mo(CO)6. The Mo(CO)6/organocatalyst binary system has shown to be a highly active catalyst for the N-alkylation reaction between alcohols and amines with excellent tolerance of variable starting materials bearing different functional groups. Of particular note, this method possessing a superiority selectivity in the synthesis of N-alkylated amines or imines, which can be controlled by the reaction temperature. The cooperative catalysis mechanism in combination of Mo(CO)6 with organocatalyst was elucidated by control experiments.
Synthesis ofN-aryl amines enabled by photocatalytic dehydrogenation
Kim, Jungwon,Kim, Siin,Choi, Geunho,Lee, Geun Seok,Kim, Donghyeok,Choi, Jungkweon,Ihee, Hyotcherl,Hong, Soon Hyeok
, p. 1915 - 1923 (2021/02/22)
Catalytic dehydrogenation (CD)viavisible-light photoredox catalysis provides an efficient route for the synthesis of aromatic compounds. However, access toN-aryl amines, which are widely utilized synthetic moieties,viavisible-light-induced CD remains a significant challenge, because of the difficulty in controlling the reactivity of amines under photocatalytic conditions. Here, the visible-light-induced photocatalytic synthesis ofN-aryl amines was achieved by the CD of allylic amines. The unusual strategy using C6F5I as an hydrogen-atom acceptor enables the mild and controlled CD of amines bearing various functional groups and activated C-H bonds, suppressing side-reaction of the reactiveN-aryl amine products. Thorough mechanistic studies suggest the involvement of single-electron and hydrogen-atom transfers in a well-defined order to provide a synergistic effect in the control of the reactivity. Notably, the back-electron transfer process prevents the desired product from further reacting under oxidative conditions.
Base-mediated cascade amidination/: N -alkylation of amines by alcohols
Hu, Mao-Lin,Jia, Xiaofei,Liang, Zuyu,Lu, Fenghong,Zhang, Chunyan,Zhang, Guoying
supporting information, p. 10489 - 10492 (2020/10/02)
A base-mediated cascade amidination/N-alkylation reaction of amines by alcohols has been developed. For the first time, nitriles have been identified as an efficient and benign water acceptor reagent in N-alkylation. Notably, the procedure tolerates a series of functional groups, such as methoxyl, halo, vinyl and hetero groups, providing a convenient method to construct different substituted diamino compounds, 15N labeled amine and could be scaled up to 1 mol scale offering 138.7 g of the desired product in good yield in one-pot. Mechanistic studies provided strong evidence for the amidination of amines with nitriles facilitated by t-BuOK.
Distinctive reactivity of N-benzylidene-[1,1'-biphenyl]-2-amines under photoredox conditions
Cho, Eun Jin,Iqbal, Naeem,Min, Kwan Hong,Tambe, Shrikant D.
, p. 1335 - 1342 (2020/07/10)
A simple photocatalytic method was developed for the synthesis of unsymmetrical 1,2-diamines by the unprecedented reductive coupling of N-benzylidene-[1,1'-biphenyl]-2-amines with an aliphatic amine. The presence of a phenyl substituent in the aniline moiety of the substrate was critical for the reactivity. The reaction proceeded via radical–radical cross-coupling of α-amino radicals generated by proton-coupled single-electron transfer in the presence of an Ir photocatalyst. On the other hand, symmetrical 1,2-di-amines were selectively produced from the same starting materials by the judicious choice of the reaction conditions, showcasing the distinct reactivity of N-benzylidene-[1,1'-biphenyl]-2-amines. The developed method can be employed for the synthesis of various bulky vicinal diamines, which are potential ligands in stereoselective synthesis.
