17123-83-0Relevant academic research and scientific papers
Mechanistic Elucidation of Zirconium-Catalyzed Direct Amidation
Lundberg, Helena,Tinnis, Fredrik,Zhang, Jiji,Algarra, Andrés G.,Himo, Fahmi,Adolfsson, Hans
, p. 2286 - 2295 (2017)
The mechanism of the zirconium-catalyzed condensation of carboxylic acids and amines for direct formation of amides was studied using kinetics, NMR spectroscopy, and DFT calculations. The reaction is found to be first order with respect to the catalyst and has a positive rate dependence on amine concentration. A negative rate dependence on carboxylic acid concentration is observed along with S-shaped kinetic profiles under certain conditions, which is consistent with the formation of reversible off-cycle species. Kinetic experiments using reaction progress kinetic analysis protocols demonstrate that inhibition of the catalyst by the amide product can be avoided using a high amine concentration. These insights led to the design of a reaction protocol with improved yields and a decrease in catalyst loading. NMR spectroscopy provides important details of the nature of the zirconium catalyst and serves as the starting point for a theoretical study of the catalytic cycle using DFT calculations. These studies indicate that a dinuclear zirconium species can catalyze the reaction with feasible energy barriers. The amine is proposed to perform a nucleophilic attack at a terminal η2-carboxylate ligand of the zirconium catalyst, followed by a C-O bond cleavage step, with an intermediate proton transfer from nitrogen to oxygen facilitated by an additional equivalent of amine. In addition, the DFT calculations reproduce experimentally observed effects on reaction rate, induced by electronically different substituents on the carboxylic acid.
Desulfurizing agent for thioamides
Polushina,Zavarzin,Krayushkin,Rodionova,Yarovenko
, p. 383 - 385 (2021/03/03)
Thioamides treated with thionyl chloride in an ionic liquid were successfully converted into amides.
Efficient and accessible silane-mediated direct amide coupling of carboxylic acids and amines
D'Amaral, Melissa C.,Jamkhou, Nick,Adler, Marc J.
supporting information, p. 288 - 295 (2021/01/28)
A straightforward method for the direct synthesis of amides from amines and carboxylic acids without exclusion of air or moisture using diphenylsilane with N-methylpyrrolidine has been developed. Various amides are made efficiently, and broad functional group compatibility is shown through a Glorius robustness study. A gram-scale synthesis demonstrates the scalability of this method. This journal is
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.
Structure–activity relationships (SARs) of α- ketothioamides as inhibitors of phosphoglycerate dehydrogenase (PHGDH)
Spillier, Quentin,Ravez, Séverine,Unterlass, Judith,Corbet, Cyril,Degavre, Charline,Feron, Olivier,Frédérick, Rapha?l
, (2020/02/11)
For many years now, targeting deregulation within cancer cells’ metabolism has appeared as a promising strategy for the development of more specific and efficient cancer treatments. Recently, numerous reports highlighted the crucial role of the serine synthetic pathway, and particularly of the phosphoglycerate dehydrogenase (PHGDH), the first enzyme of the pathway, to sustain cancer progression. Yet, because of very weak potencies usually in cell-based settings, the inhibitors reported so far failed to lay ground on the potential of this approach. In this paper, we report a structure–activity relationship study of a series of α-ketothioamides that we have recently identified. Interestingly, this study led to a deeper understanding of the structure–activity relationship (SAR) in this series and to the identification of new PHGDH inhibitors. The activity of the more potent compounds was confirmed by cellular thermal shift assays and in cell-based experiments. We hope that this research will eventually provide a new entry point, based on this promising chemical scaffold, for the development of therapeutic agents targeting PHGDH.
Ni-Catalyzed Regiodivergent and Stereoselective Hydroalkylation of Acyclic Branched Dienes with Unstabilized C(sp3) Nucleophiles
Shao, Wen,Besnard, Céline,Guénée, Laure,Mazet, Clément
supporting information, p. 16486 - 16492 (2020/10/26)
Two complementary regiodivergent [(P,N)Ni]-catalyzed hydroalkylations of branched dienes are reported. When amides are employed as unstabilized C(sp3) nucleophiles, a highly regioselective 1,4-addition process is favored. The addition products are obtained in high yield and with excellent stereocontrol of the internal olefin. With use of a chiral ligand and imides as carbon nucleophiles, a 3,4-addition protocol was developed, enabling construction of two contiguous tertiary stereocenters in a single step with moderate to high levels of diastereocontrol and excellent enantiocontrol. Both methods operate under mild reaction conditions, display a broad scope, and show excellent functional group tolerance. The synthetic potential of the 3,4-hydroalkylation reaction was established via a series of postcatalytic modifications.
Phenysilane and Silicon Tetraacetate: Versatile Promotors for Amide Synthesis
Morisset, Eléonore,Chardon, Aurélien,Rouden, Jacques,Blanchet, Jér?me
supporting information, p. 388 - 392 (2020/01/24)
Phenylsilane was reevaluated as a useful coupling reagent for amide synthesis. At room temperature, a wide range of amides and peptides were obtained in good to excellent yields (up to 99 %). For the first time, Weinreb amides synthesis mediated by a hydrosilane were also documented. Comparative experiments with various acetoxysilanes suggested the involvement of a phenyl-triacyloxysilane. From this mechanistic study, silicon tetraacetate was shown as an efficient amine acylating agent.
Direct amide formation in a continuous-flow system mediated by carbon disulfide
Orsy, Gy?rgy,Fül?p, Ferenc,Mándity, István M.
, p. 7814 - 7818 (2020/12/28)
Amide bonds are ubiquitous in nature. They can be found in proteins, peptides, alkaloids, etc. and they are used in various synthetic drugs too. Amide bonds are mainly made by the use of (i) hazardous carboxylic acid derivatives or (ii) expensive coupling agents. Both ways make the synthetic technology less atom economic. We report a direct flow-based synthesis of amides. The developed approach is prominently simple and various aliphatic and aromatic amides were synthetized with excellent yields. The reaction in itself is carried out in acetonitrile, which is considered as a less problematic dipolar aprotic solvent. The used coupling agent, carbon disulfide, is widely available and has a low price. The utilized heterogeneous Lewis acid, alumina, is a sustainable material and it can be utilized multiple times. The technology is considerably robust and shows excellent reusability and easy scale-up is carried out without the need of any intensive purification protocols.
A solid-supported arylboronic acid catalyst for direct amidation
Du, Yihao,Barber, Thomas,Lim, Sol Ee,Rzepa, Henry S.,Baxendale, Ian R.,Whiting, Andrew
supporting information, p. 2916 - 2919 (2019/03/27)
An efficient heterogeneous amidation catalyst has been prepared by co-polymerisation of styrene, DVB with 4-styreneboronic acid, which shows wide substrate applicability and higher reactivity than the equivalent homogeneous phenylboronic acid, suggesting potential cooperative catalytic effects. The catalyst can be easily recovered and reused; suitable for use in packed bed flow reactors.
Cu-Catalysed oxidative amidation of cinnamic acids/arylacetic acids with 2° amines: An efficient synthesis of α-ketoamides
Sharma, Anup Kumar,Jaiswal, Anjali,Singh, Krishna Nand
supporting information, p. 9348 - 9351 (2019/11/11)
A new and convenient copper-catalysed synthesis of α-ketoamides has been accomplished using readily available cinnamic acids/arylacetic acids and 2° amines in an open atmosphere. The reaction between cinnamic acid and amine involves the formation of enamine followed by its aerobic oxidation, whereas the reaction of arylacetic acid with amine involves amide formation followed by benzylic methylene oxidation.
