Iron-catalysed sequential reaction towards α-aminonitriles from secondary amines, primary alcohols and trimethylsilyl cyanide

2016 ◽  
Vol 52 (13) ◽  
pp. 2776-2779 ◽  
Author(s):  
Hang Shen ◽  
Liangzhen Hu ◽  
Qing Liu ◽  
Muhammad Ijaz Hussain ◽  
Jing Pan ◽  
...  

We developed a one-pot iron-catalysed sequential reaction of secondary amines under mild reaction conditions to give the corresponding α-aminonitriles.

ChemInform ◽  
2016 ◽  
Vol 47 (24) ◽  
Author(s):  
Hang Shen ◽  
Liangzhen Hu ◽  
Qing Liu ◽  
Muhammad Ijaz Hussain ◽  
Jing Pan ◽  
...  

2017 ◽  
Vol 41 (1) ◽  
pp. 42-44 ◽  
Author(s):  
Jilla Sanchooli ◽  
Alireza Hassanabadi

The synthesis of α-benzylamino pyrones is described involving the reaction of 4-hydroxy-6-methyl-2 H-pyran-2-one with aromatic aldehydes and secondary amines in the presence of oxalic acid and in aqueous media. The salient features of this protocol are aerobic conditions, short reaction times, milder reaction conditions without additives and high yields.


RSC Advances ◽  
2015 ◽  
Vol 5 (72) ◽  
pp. 58587-58594 ◽  
Author(s):  
Juthanat Kaeobamrung ◽  
Asan Lanui ◽  
Sirinad Mahawong ◽  
Witthawin Duangmak ◽  
Vatcharin Rukachaisirikul

Trisubstituted ureas can be synthesized in a one-pot fashion from bench-stable α-chloroaldoxime O-methanesulfonates and secondary amines under mild reaction conditions.


Molecules ◽  
2020 ◽  
Vol 25 (2) ◽  
pp. 410
Author(s):  
Emanuela Calcio Gaudino ◽  
Elisa Acciardo ◽  
Silvia Tabasso ◽  
Maela Manzoli ◽  
Giancarlo Cravotto ◽  
...  

The optimization of sustainable protocols for reductive amination has been a lingering challenge in green synthesis. In this context, a comparative study of different metal-loaded cross-linked cyclodextrins (CDs) were examined for the microwave (MW)-assisted reductive amination of aldehydes and ketones using either H2 or formic acid as a hydrogen source. The Pd/Cu heterogeneous nanocatalyst based on Pd (II) and Cu (I) salts embedded in a β-CD network was the most efficient in terms of yield and selectivity attained. In addition, the polymeric cross-linking avoided metal leaching, thus enhancing the process sustainability; good yields were realized using benzylamine under H2. These interesting findings were then applied to the MW-assisted one-pot synthesis of secondary amines via a tandem reductive amination of benzaldehyde with nitroaromatics under H2 pressure. The formation of a CuxPdy alloy under reaction conditions was discerned, and a synergic effect due to the cooperation between Cu and Pd has been hypothesized. During the reaction, the system worked as a bifunctional nanocatalyst wherein the Pd sites facilitate the reduction of nitro compounds, while the Cu species promote the subsequent imine hydrogenation affording structurally diverse secondary amines with high yields.


2020 ◽  
Vol 17 (3) ◽  
pp. 211-215
Author(s):  
Da Chen ◽  
Xuan Wang ◽  
Runnan Wang ◽  
Yao Zhan ◽  
Xiaohan Peng ◽  
...  

The Friedlander reaction is the most commonly used method to synthesis substituted quinolines, the essential intermediates in the medicine industry. A facile one-pot approach for synthesizing substituted quinolines by the reaction of isoxazoles, ammonium formate-Pd/C, concentrated sulfuric acid, methanol and ketones using Friedlander reaction conditions is reported. Procedures for the synthesis of quinoline derivatives were optimized, and the yield was up to 90.4%. The yield of aromatic ketones bearing electron-withdrawing groups was better than the ones with electron-donating substituents. The structures of eight substituted quinolines were characterized by MS, IR, H-NMR and 13CNMR, which were in agreement with the expected structures. The mechanism for the conversion was proposed, which involved the Pd/C catalytic hydrogen transfer reduction of unsaturated five-membered ring of isoxazole to produce ortho-amino aromatic ketones. Then the nucleophilic addition of with carbonyl of the ketones generated Schiff base in situ, which underwent an intermolecular aldol reaction followed by the elimination of H2O to give production of substituted quinolines. This new strategy can be readily applied for the construction of quinolines utilizing a diverse range of ketones and avoids the post-reaction separation of the o-amino aromatic ketone compounds. The conventionally used o-amino aromatic ketone compounds in Friedlander reaction to prepare substituted quinoline are laborious to synthesize and are apt to self-polymerize. While oxazole adopted in this work can be prepared at ease by the condensation of benzoacetonitrile and nitrobenzene derivatives under the catalysis of a strong base. Moreover, the key features of this protocol are readily available starting materials, excellent functional group tolerance, mild reaction conditions, operational simplicity, and feasibility for scaling up.


2020 ◽  
Vol 17 ◽  
Author(s):  
Visarapu Malathi ◽  
Pedavenkatagari Narayana Reddy ◽  
Pannala Padmaja

Abstract:: An efficient method has been developed for the synthesis of new pyrano[3,2-c] and pyrano[3,2-a]carbazole de-rivatives via a three component reaction of 4-hydroxycarbazole or 2-hydroxycarbazole, isocyanides, and dialkylacetylenedi-carboxylates. Noteworthy features of this protocol include mild reaction conditions, catalyst-free, high atom-economy and high yields.


2018 ◽  
Vol 15 (3) ◽  
pp. 380-387
Author(s):  
Xia Zhao ◽  
Xiaoyu Lu ◽  
Lipeng Zhang ◽  
Tianjiao Li ◽  
Kui Lu

Aim and Objective: Pyrazolone sulfones have been reported to exhibit herbicidal and antibacterial activities. In spite of their good bioactivities, only a few methods have been developed to prepare pyrazolone sulfones. However, the substrate scope of these methods is limited. Moreover, the direct sulfonylation of pyrazolone by aryl sulfonyl chloride failed to give pyrazolone sulfones. Thus, developing a more efficient method to synthesize pyrazolone sulfones is very important. Materials and Method: Pyrazolone, aryl sulphonyl hydrazide, iodine, p-toluenesulphonic acid and water were mixed in a sealed tube, which was heated to 100°C for 12 hours. The mixture was cooled to 0°C and m-CPBA was added in batches. The mixture was allowed to stir for 30 min at room temperature. The crude product was purified by silica gel column chromatography to afford sulfuryl pyrazolone. Results: In all cases, the sulfenylation products were formed smoothly under the optimized reaction conditions, and were then oxidized to the corresponding sulfones in good yields by 3-chloroperoxybenzoic acid (m-CPBA) in water. Single crystal X-ray analysis of pyrazolone sulfone 4aa showed that the major tautomer of pyrazolone sulfones was the amide form instead of the enol form observed for pyrazolone thioethers. Moreover, the C=N double bond isomerized to form an α,β-unsaturated C=C double bond. Conclusion: An efficient method to synthesize pyrazolone thioethers by iodine-catalyzed sulfenylation of pyrazolones with aryl sulfonyl hydrazides in water was developed. Moreover, this method was employed to synthesize pyrazolone sulfones in one-pot by subsequent sulfenylation and oxidation reactions.


Synthesis ◽  
2020 ◽  
Author(s):  
Peter Ehlers ◽  
Peter Langer ◽  
Marian Blanco Ponce ◽  
Silvio Parpart ◽  
Alexander Villinger ◽  
...  

AbstractA concise and modular synthesis of pyrrolo[1,2-a][1,6]- and [1,8]naphthyridines by a one-pot two-step reaction consisting of electrophilic acylation followed by an alkyne-carbonyl-metathesis reaction as the final cyclization step is reported. This developed synthetic methodology allows the facile synthesis of these heterocyclic core structures in mainly high overall yields under metal-free conditions. Reaction conditions are carefully optimized and display a novel supplement to access these tricyclic heterocyclic compounds.


2021 ◽  
Vol 505 ◽  
pp. 111504
Author(s):  
Lin Liu ◽  
Wenxiu Li ◽  
Ran Qi ◽  
Qingqing Zhu ◽  
Jing Li ◽  
...  

2020 ◽  
Vol 56 (55) ◽  
pp. 7665-7668 ◽  
Author(s):  
Lu Liu ◽  
Lei Li ◽  
Shukuan Mao ◽  
Xin Wang ◽  
Ming-Dong Zhou ◽  
...  

Various o-alkenyl aromatic isocyanides were prepared from readily available reactants for their double annulation with diazo compounds for a one-pot synthesis of pyrazolo[1,5-c]quinazolines under mild reaction conditions.


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