90811-55-5Relevant academic research and scientific papers
Continuous flow heterogeneous catalytic reductive aminations under aqueous micellar conditions enabled by an oscillatory plug flow reactor
?tv?s, Sándor B.,Buchholcz, Balázs,Darvas, Ferenc,Kappe, C. Oliver,Novák, Zoltán,Sipos, Gellért,Wernik, Michaela
supporting information, p. 5625 - 5632 (2021/08/16)
Despite the fact that continuous flow processing exhibits well-established technical advances, aqueous micellar chemistry, a field that has proven extremely useful in shifting organic synthesis to sustainable water-based media, has mostly been explored under conventional batch-based conditions. This is particularly because of the fact that the reliable handling of slurries and suspensions in flow has been considered as a significant technical challenge. Herein, we demonstrate that the strategic application of an oscillatory plug flow reactor enables heterogeneous catalytic reductive aminations in aqueous micellar media enhancing mass transport and facilitating process simplicity, stability and scalability. The micellar flow process enabled a broad range of substrates, including amino acid derivatives, to be successfully transformed under reasonably mild conditions utilizing only very low amounts of Pd/C as a readily available heterogeneous catalyst. The preparative capabilities of the process along with the recyclability of the heterogenous catalyst and the aqueous reaction media were also demonstrated. This journal is
[(PPh3)2NiCl2]-Catalyzed C-N bond formation reaction via borrowing hydrogen strategy: Access to diverse secondary amines and quinolines
Donthireddy,Pandey, Vipin K.,Rit, Arnab
, p. 6994 - 7001 (2021/06/09)
Commercially available [(PPh3)2NiCl2] was found to be an efficient catalyst for the mono-N-alkylation of (hetero)- A romatic amines, employing alcohols to deliver diverse secondary amines, including the drug intermediates chloropyramine (5b) and mepyramine (5c), in excellent yields (up to 97%) via the borrowing hydrogen strategy. This method shows a superior activity (TON up to 10000) with a broad substrate scope at a low catalyst loading of 1 mol % and a short reaction time. Further, this strategy is also successful in accessing various quinoline derivatives following the acceptorless dehydrogenation pathway.
A Fe single atom on N,S-doped carbon catalyst for performing N-alkylation of aromatic amines under solvent-free conditions
Lin, Yamei,Lu, Guo-Ping,Shan, Hongbin,Wang, Pengcheng,Zhang, Kai,Zhong, Qin,Zhou, Baojing
supporting information, p. 25128 - 25135 (2021/11/26)
A green and gram-scale strategy has been developed for the synthesis of Fe single atom/N,S-doped carbon catalyst (Fe20-SA@NSC) via the pyrolysis of polyaniline (PAN)-modified Fe,S-doped ZIFs, in which the synthesis of ZIFs can be accomplished in water at room temperature. The as-prepared catalyst exhibits superior activity in the N-alkylation of amines with alcohols via a borrowing strategy under solvent-free conditions (TOF up to 13.9 h-1). Based on the HAADF-STEM and XAFS results, Fe in this material is dispersed as the single-atom Fe1-N4S1 site. According to the experimental and theoretical calculation results, the Fe1-N4S1 site displays a better borrowing hydrogen ability than other Fe sites owing to its higher electron density. In addition, this catalyst has excellent stability and recyclability, and no obvious loss in activity is observed after 7 runs.
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.
Visible-light-enabled regioselective aerobic oxidative C(sp2)-H thiocyanation of aromatic compounds by Eosin-Y photocatalyst
Yi, Bing,Wen, Xiaoyong,Yi, Ziqi,Xie, Yanjun,Wang, Qiang,Tan, Jian-Ping
supporting information, (2020/11/19)
Herein, visible-light-enabled regioselective aerobic oxidative C(sp2)-H thiocyanation of aromatic compounds has been developed by employing eosin-Y as effective photocatalyst and oxygen as the green terminal oxidant. This process featured green, efficient and operationally simple. Furthermore, the practicality and utility of this protocol was demonstrated by the gram scale synthesis. Mechanistic studies suggested that this reaction was realized via a photoredox radical pathway.
Direct electrochemical reductive amination between aldehydes and amines with a H/D-donor solvent
Chen, Lu,Hong, Huanliang,Hu, Jinhui,Huang, Yubing,Li, Yibiao,Liang, Gen,Pu, Suyun,Zhu, Zhongzhi,Zou, Zirong
supporting information, p. 5832 - 5837 (2020/11/03)
A novel electrochemical synthesis protocol has been achieved for reductive amination between aldehydes and amines in undivided cells at room temperature. Under metal-free and external-reductant-free electrolysis conditions, various important secondary amine products are obtained in moderate-to-high yields. Deuterium-labeling experiments have demonstrated that low-toxicity DMSO acts both as a solvent and a H-donor in the reaction. On this basis, various deuterium-labeled products with good-to-excellent D-incorporation have been synthesized by using DMSO-d6 as a solvent. Furthermore, a molecule with GR-antagonistic activity has been synthesized through further sulfonylation.
Catalyst- And solvent-free efficient access to: N -alkylated amines via reductive amination using HBpin
Bauri, Somnath,Pandey, Vipin K.,Rit, Arnab
, p. 3853 - 3857 (2020/07/27)
A sustainable approach which works under catalyst- and solvent-free conditions for the synthesis of structurally diverse secondary amines has been uncovered. This one-pot protocol works efficiently at room temperature and is compatible with a wide range of sterically and electronically diverse aldehydes and primary amines. Notably, this simple process offers scalability, excellent functional group tolerance, chemoselectivity, and is also effective at the synthesis of biologically relevant molecules. This journal is
Dialkylterphenyl Phosphine-Based Palladium Precatalysts for Efficient Aryl Amination of N-Nucleophiles
Rama, Raquel J.,Maya, Celia,Nicasio, M. Carmen
supporting information, p. 1064 - 1073 (2020/01/25)
A series of 2-aminobiphenyl palladacycles supported by dialkylterphenyl phosphines, PR2Ar′ (R=Me, Et, iPr, Cyp (cyclopentyl), Ar′=ArDipp2, ArXyl2f, Dipp (2,6-C6H3-(2,6-C6H3-(CHMe2)2)2), Xyl=xylyl) have been prepared and structurally characterized. Neutral palladacycles were obtained with less bulky terphenyl phosphines (i.e., Me and Et substituents) whereas the largest phosphines provided cationic palladacycles in which the phosphines adopted a bidentate hemilabile k1-P,η1-Carene coordination mode. The influence of the ligand structure on the catalytic performance of these Pd precatalysts was evaluated in aryl amination reactions. Cationic complexes bearing the phosphines PiPr2ArXyl2 and PCyp2ArXyl2 were the most active of the series. These precatalysts have demonstrated a high versatility and efficiency in the coupling of a variety of nitrogen nucleophiles, including secondary amines, alkyl amines, anilines, and indoles, with electronically deactivated and ortho-substituted aryl chlorides at low catalyst loadings (0.25–0.75 mol % Pd) and without excess ligand.
Base-Mediated Amination of Alcohols Using Amidines
Chen, Jianbin,Fang, Yanchen,Jia, Xiaofei,Jiang, Shaohua,Li, Zehua,Liang, Zuyu,Lu, Fenghong,Qi, Shuo,Ren, Chaoyu,Yu, Shuangming,Zhang, Chunyan,Zhang, Guoying,Zhang, Sheng
, p. 7728 - 7738 (2020/07/15)
Novel and efficient base-mediated N-alkylation and amidation of amidines with alcohols have been developed, which can be carried out in one-pot reaction conditions, which allows for the synthesis of a wide range of N-alkyl amines and free amides in good to excellent yields with high atom economy. In contrast to borrowing hydrogen/hydrogen autotransfer or oxidative-type N-alkylation reactions, in which alcohols are activated by transition-metal-catalyzed or oxidative aerobic dehydrogenation, the use of amidines provides an effective surrogate of amines. This circumvents the inherent necessity in N-alkylation of an oxidant or a catalyst to be stabilized by ligands.
Pyridine mediated transition-metal-free direct alkylation of anilines using alcohols: via borrowing hydrogen conditions
Pothikumar, Rajagopal,Bhat, Venugopal T,Namitharan, Kayambu
supporting information, p. 13607 - 13610 (2020/11/17)
Herein, we report pyridine and other similar azaaromatics as efficient biomimetic hydrogen shuttles for a transition-metal-free direct N-alkylation of aryl and heteroaryl amines using a variety of benzylic and straight chain alcohols. Mechanistic studies including deuterium labeling and the isolation of dihydro-intermediates of the benzannulated pyridine confirmed the role of pyridine and a borrowing hydrogen process operating in these reactions. In addition, we have extended this methodology for the development of dehydrogenative synthesis of quinolines and indoles, as well as the transfer hydrogenation of ketones. This journal is
