Xn:Harmful;
55-21-0Relevant academic research and scientific papers
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.
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.
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.
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
The polyhedral nature of selenium-catalysed reactions: Se(iv) species instead of Se(vi) species make the difference in the on water selenium-mediated oxidation of arylamines
Capperucci, Antonella,Dalia, Camilla,Tanini, Damiano
supporting information, p. 5680 - 5686 (2021/08/16)
Selenium-catalysed oxidations are highly sought after in organic synthesis and biology. Herein, we report our studies on the on water selenium mediated oxidation of anilines. In the presence of diphenyl diselenide or benzeneseleninic acid, anilines react with hydrogen peroxide, providing direct and selective access to nitroarenes. On the other hand, the use of selenium dioxide or sodium selenite leads to azoxyarenes. Careful mechanistic analysis and 77Se NMR studies revealed that only Se(iv) species, such as benzeneperoxyseleninic acid, are the active oxidants involved in the catalytic cycle operating in water and leading to nitroarenes. While other selenium-catalysed oxidations occurring in organic solvents have been recently demonstrated to proceed through Se(vi) key intermediates, the on water oxidation of anilines to nitroarenes does not. These findings shed new light on the multifaceted nature of organoselenium-catalysed transformations and open new directions to exploit selenium-based catalysis.
Cubic CuxZrO100-x as an efficient and selective catalyst for the oxidation of aromatics active methyl, alcohol, and amine groups
Bankar, Balasaheb D.,Advani, Jacky H.,Biradar, Ankush V.
, (2021/03/14)
The local structure of a supported active metal plays a vital role in determining the desired product's selectivity in heterogeneous catalysis. Herein, we have developed a simple protocol for the synthesis of Cu doped on cubic ZrO2 mixed metal oxide catalysts and used it for the selective oxidation of various functional groups. The catalyst was synthesized by varying the wt.% of Cu (1–20%) on ZrO2 by co-precipitation, followed by hydrothermal treatment. The X-ray diffraction pattern of the catalysts confirmed the formation of the cubic phase of ZrO2, and the growth of CuO occurred along the (1 1 1) plane. The microscopy analysis revealed the uniform distribution of Cu on the ZrO2 surface, while XPS analysis confirmed the presence of copper in the +2 oxidation state. The synthesized catalyst with 2 wt% loading of Cu on ZrO2 showed excellent liquid-phase oxidation properties and gave good to best conversion of active methyl groups, alcohols, and amines with high selectivities to corresponding ketones, aldehydes, and amides, respectively, under milder reaction conditions. Furthermore, the synthesized catalyst showed a broader substrate scope for the various substituted active methyl groups, alcohols, and amines with good conversion and selectivity.
Ruthenium(II) complexes bearing bidentate acylthiourea ligands for direct oxidation of amine α-carbon to amide
Aslan, Muhammed,Gumus, Ilkay
, (2021/10/07)
In this study, the synthesis and structural characterization of ruthenium complexes supported by S,O-acylthiourea ligands (L1-L6) with different substituent groups as well as auxiliary ligands PPH3, CO, and Cl and their evaluation as catalysts for direct oxidation of the α-methylene group in amines were reported. Ru(II) complexes, Ru1-Ru6, were prepared from the reaction of the RuH(CO)Cl(PPh3)3 precursor and ligands L1-L6 having different electronic and steric properties. The ligands and complexes prepared were characterized by FT-IR, 1H–13C- and/or 31P NMR spectroscopic techniques. The molecular structures of Ru1 and Ru3 complexes with appropriate crystal quality were also confirmed by X-ray single crystal analysis. Solid-state structures of Ru1 and Ru3 revealed that the ruthenium center is surrounded by one carbonyl, one chloride, two PPh3 ligands, and the S,O-donor atoms from the acylthiourea ligand in bidentate monoanionic form. The catalytic activity of all complexes for the α-oxygenation reactions of primary benzylic amines to amides was investigated. Overall, all catalysts exhibited excellent activity and selectivity towards the formation of amide production under the present reaction conditions. In addition, both catalyst activation and product selectivity/formation were particularly dependent on the amount/type of base and oxygen.
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.
Visible light-mediated synthesis of amides from carboxylic acids and amine-boranes
Chen, Xuenian,Kang, Jia-Xin,Ma, Yan-Na,Miao, Yu-Qi
supporting information, p. 3595 - 3599 (2021/06/06)
Here, a photocatalytic deoxygenative amidation protocol using readily available amine-boranes and carboxylic acids is described. This approach features mild conditions, moderate-to-good yields, easy scale-up, and up to 62 examples of functionalized amides with diverse substituents. The synthetic robustness of this method was also demonstrated by its application in the late-stage functionalization of several pharmaceutical molecules.
