Xn:Harmful;
55-21-0Relevant articles and documents
AMINE-BORANES AS BIFUNCTIONAL REAGENTS FOR DIRECT AMIDATION OF CARBOXYLIC ACIDS
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Paragraph 0008-0009; 0063-0064, (2022/03/04)
The present invention generally relates to a process for selective and direct activation and subsequent amidation of aliphatic and aromatic carboxylic acids to afford an amide R3CONR1R2. That the process is capable of delivering gaseous or low-boiling point amines provides a major advantage over existing methodologies, which involves an intermediate of triacyloxyborane-amine complex [(R3CO2)3—B—NHR1R2]. This procedure readily produces primary, secondary, and tertiary amides, and is compatible with the chirality of the acid and amine involved. The preparation of known pharmaceutical molecules and intermediates has also been demonstrated.
Nitrogen Atom Transfer Catalysis by Metallonitrene C?H Insertion: Photocatalytic Amidation of Aldehydes
Schmidt-R?ntsch, Till,Verplancke, Hendrik,Lienert, Jonas N.,Demeshko, Serhiy,Otte, Matthias,Van Trieste, Gerard P.,Reid, Kaleb A.,Reibenspies, Joseph H.,Powers, David C.,Holthausen, Max C.,Schneider, Sven
supporting information, (2022/01/20)
C?H amination and amidation by catalytic nitrene transfer are well-established and typically proceed via electrophilic attack of nitrenoid intermediates. In contrast, the insertion of (formal) terminal nitride ligands into C?H bonds is much less developed and catalytic nitrogen atom transfer remains unknown. We here report the synthesis of a formal terminal nitride complex of palladium. Photocrystallographic, magnetic, and computational characterization support the assignment as an authentic metallonitrene (Pd?N) with a diradical nitrogen ligand that is singly bonded to PdII. Despite the subvalent nitrene character, selective C?H insertion with aldehydes follows nucleophilic selectivity. Transamidation of the benzamide product is enabled by reaction with N3SiMe3. Based on these results, a photocatalytic protocol for aldehyde C?H trimethylsilylamidation was developed that exhibits inverted, nucleophilic selectivity as compared to typical nitrene transfer catalysis. This first example of catalytic C?H nitrogen atom transfer offers facile access to primary amides after deprotection.
Aerobic oxidation of primary amines to amides catalyzed by an annulated mesoionic carbene (MIC) stabilized Ru complex
Yadav, Suman,Reshi, Noor U Din,Pal, Saikat,Bera, Jitendra K.
, p. 7018 - 7028 (2021/11/17)
Catalytic aerobic oxidation of primary amines to the amides, using the precatalyst [Ru(COD)(L1)Br2] (1) bearing an annulated π-conjugated imidazo[1,2-a][1,8]naphthyridine-based mesoionic carbene ligand L1, is disclosed. This catalytic protocol is distinguished by its high activity and selectivity, wide substrate scope and modest reaction conditions. A variety of primary amines, RCH2NH2 (R = aliphatic, aromatic and heteroaromatic), are converted to the corresponding amides using ambient air as an oxidant in the presence of a sub-stoichiometric amount of KOtBu in tBuOH. A set of control experiments, Hammett relationships, kinetic studies and DFT calculations are undertaken to divulge mechanistic details of the amine oxidation using 1. The catalytic reaction involves abstraction of two amine protons and two benzylic hydrogen atoms of the metal-bound primary amine by the oxo and hydroxo ligands, respectively. A β-hydride transfer step for the benzylic C-H bond cleavage is not supported by Hammett studies. The nitrile generated by the catalytic oxidation undergoes hydration to afford the amide as the final product. This journal is
Ru(ii)- And Ru(iv)-dmso complexes catalyze efficient and selective aqueous-phase nitrile hydration reactions under mild conditions
Dubey, Santosh Kumar,Kaur, Gurmeet,Rath, Nigam P.,Trivedi, Manoj
, p. 17339 - 17346 (2021/10/08)
New water-soluble ruthenium(ii)- and ruthenium(iv)-dmso complexes [RuCl2(dmso)2(NH3)(CH3CN)] (1), [RuCl2(dmso)3(CH3CN)] (2), and [RuCl2(dmso)3(NH3)]·PF6·Cl (3) have been synthesized and characterized using elemental analyses, IR, 1H and 31P NMR, and electronic absorption spectroscopy. The molecular structures of complexes 1-3 were determined crystallographically. The reactivity of complexes 1-3 has been tested for aqueous-phase nitrile hydration at 60 °C in air, and good efficiency and selectivity are shown for the corresponding amide derivatives. Best performance is achieved with complex 3. Amide conversions of 56-99% were obtained with a variety of aromatic, alkyl, and vinyl nitriles. The reaction tolerated hydroxyl, nitro, bromo, formyl, pyridyl, benzyl, alkyl, and olefinic functional groups. Amides were isolated by simple decantation from the aqueous-phase catalyst. A catalyst loading down to 0.0001 mol% was examined and turnover numbers as high as 990?000 were observed. The catalyst was stable for weeks in solution and could be reused more than seven times without significant loss in catalytic activity. The gram-scale reaction was also performed to produce the desired product in high yields. This journal is
Mechanochemical Synthesis of Primary Amides
Gómez-Carpintero, Jorge,Sánchez, J. Domingo,González, J. Francisco,Menéndez, J. Carlos
, p. 14232 - 14237 (2021/10/20)
Ball milling of aromatic, heteroaromatic, vinylic, and aliphatic esters with ethanol and calcium nitride afforded the corresponding primary amides in a transformation that was compatible with a variety of functional groups and maintained the integrity of a stereocenter α to carbonyl. This methodology was applied to α-amino esters and N-BOC dipeptide esters and also to the synthesis of rufinamide, an antiepileptic drug.
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.
A mild and selective Cu(II) salts-catalyzed reduction of nitro, azo, azoxy, N-aryl hydroxylamine, nitroso, acid halide, ester, and azide compounds using hydrogen surrogacy of sodium borohydride
Kalola, Anirudhdha G.,Prasad, Pratibha,Mokariya, Jaydeep A.,Patel, Manish P.
supporting information, p. 3565 - 3589 (2021/10/12)
The first mild, in situ, single-pot, high-yielding well-screened copper (II) salt-based catalyst system utilizing the hydrogen surrogacy of sodium borohydride for selective hydrogenation of a broad range of nitro substrates into the corresponding amine under habitancy of water or methanol like green solvents have been described. Moreover, this catalytic system can also activate various functional groups for hydride reduction within prompted time, with low catalyst-loading, without any requirement of high pressure or molecular hydrogen supply. Notably, this system explores a great potential to substitute expensive traditional hydrogenation methodologies and thus offers a greener and simple hydrogenative strategy in the field of organic synthesis.
Method for preparing primary and secondary amide compounds
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Paragraph 0035-0045, (2021/02/06)
The invention belongs to the field of organic chemical synthesis, and particularly relates to a method for preparing primary and secondary amide compounds. The method for preparing primary and secondary amide compounds comprises the following steps of carrying out catalytic reduction on an N-substituted amide compound at 30-130 DEG C by using a protic solvent as a reduction reagent and a dichloro(p-methyl isopropylbenzene) ruthenium (II) dimer complex as a catalyst to obtain a reaction solution after the reduction reaction is finished, and carrying out post-treatment on the reaction solution to obtain the corresponding primary amide compound or secondary amide compound. According to the method for preparing the primary and secondary amide compounds, the transfer hydrogenation reaction of nitrogen-oxygen and nitrogen-carbon bonds is realized, the reaction conditions are mild and simple, the substrate application range is wide, the operation is convenient, and the corresponding primary amide compound or secondary amide compound is obtained with high efficiency and high selectivity.
Method for efficiently synthesizing primary amide and N-methyl secondary amide compounds
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Paragraph 0007; 0011, (2021/08/07)
The invention discloses a method for efficiently synthesizing primary amide and N-methyl secondary amide compounds, which specifically comprises the following steps: adding metal amine borane MRNHBH3 into a reaction container filled with anhydrous THF (tetrahydrofuran) under anhydrous and anaerobic conditions, wherein M=Na or K, and R=H or Me; adding an ester compound R 'CO2R ''(R' is alkyl or aryl) and R'' is alkyl or aryl) into a reaction kettle, carrying out stirring reaction at room temperature, and carrying out post-treatment to obtain the pure target product primary amide compound or N-methyl secondary amide compound. The preparation method is simple to operate, low in toxicity, harmless, safe, reliable and suitable for large-scale production.
Visible-light-induced direct construction of amide bond from carboxylic acids with amines in aqueous solution
Wang, Jin,Hou, Huiqing,Hu, Yongzhi,Lin, Jin,Wu, Min,Zheng, Zhiqiang,Xu, Xiuzhi
supporting information, (2021/02/09)
A novel visible-light-promoted N-acylation for the synthesis of amides from easily available carboxylic acids with amines in the presence of I2 within 2.5 h in aqueous solution has been developed. Using sunlight as the visible light source greatly reduces the cost of experiments and produces almost no toxic effects. Hence, this study provides an alternative catalytic system for the construction of a wide range of amides with readily available materials. Moreover, the strategy was successfully applied in the preparation of N-(3-(2,6-dimethoxyphenoxy)-7-nitroquinoxalin-2-yl)benzohydrazide, which displayed a signification anti-proliferation effect on A549, MCF-7 and HCT116 cell lines.
