5397-76-2Relevant academic research and scientific papers
Direct Amidation of Esters by Ball Milling**
Barreteau, Fabien,Battilocchio, Claudio,Browne, Duncan L.,Godineau, Edouard,Leitch, Jamie A.,Nicholson, William I.,Payne, Riley,Priestley, Ian
supporting information, p. 21868 - 21874 (2021/09/02)
The direct mechanochemical amidation of esters by ball milling is described. The operationally simple procedure requires an ester, an amine, and substoichiometric KOtBu and was used to prepare a large and diverse library of 78 amide structures with modest to excellent efficiency. Heteroaromatic and heterocyclic components are specifically shown to be amenable to this mechanochemical protocol. This direct synthesis platform has been applied to the synthesis of active pharmaceutical ingredients (APIs) and agrochemicals as well as the gram-scale synthesis of an active pharmaceutical, all in the absence of a reaction solvent.
Photocatalytic aldehydes/alcohols/toluenes oxidative amidation over bifunctional Pd/MOFs: Effect of Fe-O clusters and Lewis acid sites
Bian, Fengxia,Cheng, Hongmei,Jiang, Heyan,Sun, Bin,Tan, Jiangwei,Zang, Cuicui
, p. 279 - 287 (2021/08/21)
Heterogeneous photocatalytic organic synthesis is fascinating because of the utilization of ubiquitous solar light for chemical transformations. Here, three Fe-MOFs with different Fe-O clusters, Lewis acid sites and morphologies were synthesized through coordination structure engineering. Pd/Fe-MOFs nanocomposites were used to challenge the amide bond green synthesis with visible light. Pd/MIL-101(Fe) exhibited the best photocatalytic performance due to the easily excited Fe3-μ3-oxo clusters for light absorption, the efficient photogenerated carriers separation and migration, the large amount of Lewis acid sites based aldehydes and amines condensation promotion and the efficient O2 reduction to superoxide radicals over photogenerated electron-rich Pd NPs. Various aldehydes, alcohols and toluenes could be transformed to amide compounds with amines over Pd/MIL-101(Fe) with just oxygen or air as the green oxidant and water as the by-product. One-pot C–C cross-coupling and photo-redox C–N coupling cascade reactions could also be achieved over Pd/MIL-101(Fe). This work shed light on the efficient and sustainable amide bonds synthesis.
Amide Bond Formation via Aerobic Photooxidative Coupling of Aldehydes with Amines Catalyzed by a Riboflavin Derivative
Hassan Tolba, Amal,Krupi?ka, Martin,Chudoba, Josef,Cibulka, Radek
supporting information, p. 6825 - 6830 (2021/09/11)
We report an effective, operationally simple, and environmentally friendly system for the synthesis of tertiary amides by the oxidative coupling of aromatic or aliphatic aldehydes with amines mediated by riboflavin tetraacetate (RFTA), an inexpensive organic photocatalyst, and visible light using oxygen as the sole oxidant. The method is based on the oxidative power of an excited flavin catalyst and the relatively low oxidation potential of the hemiaminal formed by amine to aldehyde addition.
NaI-mediated oxidative amidation of benzyl alcohols/aromatic aldehydes to benzamides via electrochemical reaction
Rerkrachaneekorn, Tanawat,Tankam, Theeranon,Sukwattanasinitt, Mongkol,Wacharasindhu, Sumrit
supporting information, (2021/04/15)
In this research, we have developed a mild electrochemical process for oxidative amidation of benzyl alcohols/aromatic aldehydes with cyclic amines into the corresponding benzamides. This electroorganic synthetic method proceeds using NaI as a redox mediator under ambient temperature in undivided cell, providing more than 25 examples of amide products in moderate to good yields. The benefits of this reaction include one-pot synthesis, open air condition, proceed in aqueous media and no requirement of external conducting salt, base and oxidant.
Visible-Light-Driven C-N Bond Formation by a Hexanickel Cluster Substituted Polyoxometalate-Based Photocatalyst
Chang, Jiangnan,Han, Qiuxia,Jiao, Jiachen,Li, Jie,Li, Mingxue
, p. 10022 - 10029 (2021/07/19)
A powerful and attractive route to develop novel photocatalysts for C-N bond formation involves the use of pyrrolidine as the substrate and cocatalyst simultaneously. Herein, a new polyoxometalate (POM)-based metal-organic framework, namely, [Ni6(OH)3(H2O
Solar and visible-light active nano Ni/g-C3N4photocatalyst for carbon monoxide (CO) and ligand-free carbonylation reactions
Hosseini-Sarvari, Mona,Akrami, Zahra
, p. 956 - 969 (2021/02/26)
In this study, we investigate the amino and alkoxycarbonylation reaction between various substituted aryl halides, benzyl iodides, and iodocyclohexane with different types of amines and alcohols in the absence of carbon monoxide gas and ligands. Similar reactions are carried out at high temperatures, in the presence of appropriate ligands, stoichiometric amounts of bases, and gaseous carbon monoxide, which endanger the health of organic chemists. We present a novel method that does not utilize ligands, bases, gaseous CO, and special conditions. This procedure is a redox reaction carried out by new economic nano Ni/g-C3N4at room temperature and under visible light. Mo(CO)6was used toin situgenerate CO, to resolve the problems caused by the use of CO gas. This protocol has the ability to be used on a gram scale by using a continuous flow reactor.
Structure-Based Optimization of Quinazolines as Cruzain and TbrCATL Inhibitors
Barbosa Da Silva, Elany,Rocha, Débora A.,Fortes, Isadora S.,Yang, Wenqian,Monti, Ludovica,Siqueira-Neto, Jair L.,Caffrey, Conor R.,McKerrow, James,Andrade, Saulo F.,Ferreira, Rafaela S.
, p. 13054 - 13071 (2021/09/13)
The cysteine proteases, cruzain and TbrCATL (rhodesain), are therapeutic targets for Chagas disease and Human African Trypanosomiasis, respectively. Among the known inhibitors for these proteases, we have described N4-benzyl-N2-phenylquinazoline-2,4-diamine (compound 7 in the original publication, 1a in this study), as a competitive cruzain inhibitor (Ki = 1.4 μM). Here, we describe the synthesis and biological evaluation of 22 analogs of 1a, containing modifications in the quinazoline core, and in the substituents in positions 2 and 4 of this ring. The analogs demonstrate low micromolar inhibition of the target proteases and cidal activity against Trypanosoma cruzi with up to two log selectivity indices in counterscreens with myoblasts. Fourteen compounds were active against Trypanosoma brucei at low to mid micromolar concentrations. During the optimization of 1a, structure-based design and prediction of physicochemical properties were employed to maintain potency against the enzymes while removing colloidal aggregator characteristics observed for some molecules in this series.
Palladium nanoparticles on a pyridinium supported ionic liquid phase: a recyclable and low-leaching palladium catalyst for aminocarbonylation reactions
Adamcsik, Bernadett,Nagy, Enik?,Pekker, Péter,Skoda-F?ldes, Rita,Szabó, Péter,Urbán, Béla
, p. 23988 - 23998 (2020/07/14)
A new SILP (Supported Ionic Liquid Phase) palladium catalyst was prepared and characterized by 13C and 29Si CP MAS NMR, DTG, FTIR and TEM. The presence of the grafted pyridinium cations on the surface of the support was found to result in the formation of highly dispersed Pd nanoparticles with their diameter in the range of 1-2 nm. The catalyst was proved to be active not only in the aminocarbonylation of some model compounds but also in the synthesis of active pharmaceutical ingredients. Catalyst recycling and palladium leaching studies were carried out for the first time in aminocarbonylations leading to CX-546(1-(1,4-benzodioxan-6-ylcarbonyl)piperidine), Moclobemide, Nikethamide and a precursor of Finasteride. The latter reaction proves that not only aryl iodides but also an iodoalkene can be converted into the products with the help of the heterogeneous catalyst. The results show that the conditions should be always fine-tuned in the reactions of different substrates to achieve optimal results. Palladium loss was also observed to depend considerably on the nature of the reaction partners. This journal is
Double carbonylation of iodoarenes in the presence of a pyridinium SILP-Pd catalyst
Nagy, Enik?,Nagy, Petra,Papp, Máté,Skoda-F?ldes, Rita,Urbán, Béla
, (2020/04/28)
The efficiency of a palladium catalyst, immobilised on a supported ionic liquid phase (SILP) with adsorbed 1-butyl-4-methylpyridinium chloride, was investigated in aminocarbonylation reactions. Double carbonylation was found to be the main reaction using different iodoarenes and aliphatic amines as substrates. Application of aniline derivatives as nucleophiles led to the exclusive formation of substituted benzamides. The stabilisation effect of the adsorbed pyridinium ionic liquid was compared to that of imidazolium and phosphonium derivatives. It was proved that the pyridinium SILP-palladium catalyst could be reused in at least 10 cycles. Recyclability was tested in five successive runs for all of the substrates.
Two-step continuous flow synthesis of amide via oxidative amidation of methylarene
Fang, Zheng,Guo, Kai,He, Wei,Liu, Chengkou,Shi, Tingting,Yang, Yuhang,Yang, Zhao,Zhang, Zhimin
supporting information, (2020/02/28)
A green and efficient method for the synthesis of amides has been developed through oxidative amidation between methylarenes with amines in a two-step continuous flow system. This method integrates methylarene oxidation and amide formation into a single operation which is usually accomplished separately. Oxidation with tert-butyl hydroperoxide (TBHP) as “green” oxidant, the synthesis of amides under mild reaction conditions in continuous flow system and the utilization of methylarenes as starting material make this methodology novel and environment friendly. The practical value of this method is highlighted through the synthesis of high-profile pharmaceutical agents, acetylprocainamide.
