702-11-4Relevant academic research and scientific papers
Palladium-Catalyzed Reductive Aminocarbonylation of Benzylammonium Triflates with o-Nitrobenzaldehydes for the Synthesis of 3-Arylquinolin-2(1 H)-ones
Liu, Yongzhu,Qi, Xinxin,Wu, Xiao-Feng
, p. 13824 - 13832 (2021/10/12)
A palladium-catalyzed straightforward procedure for the synthesis of 3-arylquinolin-2(1H)-ones has been developed. The synthesis proceeds through a palladium-catalyzed reductive aminocarbonylation reaction of benzylic ammonium triflates with o-nitrobenzaldehydes, and a wide range of 3-arylquinolin-2(1H)-ones was obtained in moderate to good yields with very good functional group compatibility.
Pd(II)-Mediated C?H Activation for Cysteine Bioconjugation
Frost, Christopher G.,Kociok-K?hn, Gabriele,Lubben, Anneke T.,Reeksting, Shaun B.,Tilden, James A. R.
supporting information, (2022/01/19)
Selective bioconjugation remains a significant challenge for the synthetic chemist due to the stringent reaction conditions required by biomolecules coupled with their high degree of functionality. The current trailblazer of transition-metal mediated bioconjugation chemistry involves the use of Pd(II) complexes prepared via an oxidative addition process. Herein, the preparation of Pd(II) complexes for cysteine bioconjugation via a facile C?H activation process is reported. These complexes show bioconjugation efficiency competitive with what is seen in the current literature, with a user-friendly synthesis, common Pd(II) sources, and a more cost-effective ligand. Furthermore, these complexes need not be isolated, and still achieve high conversion efficiency and selectivity of a model peptide. These complexes also demonstrate the ability to selectively arylate a single surface cysteine residue on a model protein substrate, further demonstrating their utility.
Zirconium-hydride-catalyzed site-selective hydroboration of amides for the synthesis of amines: Mechanism, scope, and application
Han, Bo,Jiao, Haijun,Wu, Lipeng,Zhang, Jiong
, p. 2059 - 2067 (2021/09/02)
Developing mild and efficient catalytic methods for the selective synthesis of amines is a longstanding research objective. In this respect, catalytic deoxygenative amide reduction has proven to be promising but challenging, as this approach necessitates selective C–O bond cleavage. Herein, we report the selective hydroboration of primary, secondary, and tertiary amides at room temperature catalyzed by an earth-abundant-metal catalyst, Zr-H, for accessing diverse amines. Various readily reducible functional groups, such as esters, alkynes, and alkenes, were well tolerated. Furthermore, the methodology was extended to the synthesis of bio- and drug-derived amines. Detailed mechanistic studies revealed a reaction pathway entailing aldehyde and amido complex formation via an unusual C–N bond cleavage-reformation process, followed by C–O bond cleavage.
Facile synthesis of controllable graphene-co-shelled reusable Ni/NiO nanoparticles and their application in the synthesis of amines under mild conditions
Cui, Zhibing,Liu, Jianguo,Liu, Qiying,Ma, Longlong,Singh, Thishana,Wang, Chenguang,Wang, Nan,Zhu, Yuting
supporting information, p. 7387 - 7397 (2020/11/19)
The primary objective of many researchers in chemical synthesis is the development of recyclable and easily accessible catalysts. These catalysts should preferably be made from Earth-abundant metals and have the ability to be utilised in the synthesis of pharmaceutically important compounds. Amines are classified as privileged compounds, and are used extensively in the fine and bulk chemical industries, as well as in pharmaceutical and materials research. In many laboratories and in industry, transition metal catalysed reductive amination of carbonyl compounds is performed using predominantly ammonia and H2. However, these reactions usually require precious metal-based catalysts or RANEY nickel, and require harsh reaction conditions and yield low selectivity for the desired products. Herein, we describe a simple and environmentally friendly method for the preparation of thin graphene spheres that encapsulate uniform Ni/NiO nanoalloy catalysts (Ni/NiO?C) using nickel citrate as the precursor. The resulting catalysts are stable and reusable and were successfully used for the synthesis of primary, secondary, tertiary, and N-methylamines (more than 62 examples). The reaction couples easily accessible carbonyl compounds (aldehydes and ketones) with ammonia, amines, and H2 under very mild industrially viable and scalable conditions (80 °C and 1 MPa H2 pressure, 4 h), offering cost-effective access to numerous functionalized, structurally diverse linear and branched benzylic, heterocyclic, and aliphatic amines including drugs and steroid derivatives. We have also demonstrated the scale-up of the heterogeneous amination protocol to gram-scale synthesis. Furthermore, the catalyst can be immobilized on a magnetic stirring bar and be conveniently recycled up to five times without any significant loss of catalytic activity and selectivity for the product.
Cu2O-catalyzed C–S coupling of quaternary ammonium salts and sodium alkane-/arene-sulfinates
Chen, Hongyi,Huang, Youming,Zeng, Qingle,Zheng, Wenting
supporting information, (2020/08/28)
A new protocol for the synthesis of (enantioenriched) benzylic sulfones via the Cu2O-catalyzed C–S bond cross coupling of alkane-/arene-sulfinates and (enantioenriched) benzylic quaternary ammonium salts has been developed. The product benzylic sulfones were obtained in good to high yields (75–96%). Chiral arylmethyl sulfones with high enantiomeric excess (90–94% ee) were also synthesized in the presence of Cu2O and 1,1′-bis-(diphenylphosphino)ferrocene (dppf).
Electrochemical Dehydrogenative Imidation of N-Methyl-Substituted Benzylamines with Phthalimides for the Direct Synthesis of Phthalimide-Protected gem-Diamines
Lian, Fei,Sun, Caocao,Xu, Kun,Zeng, Chengchu
supporting information, p. 156 - 159 (2019/01/11)
A general and green electrochemical dehydrogenative method for the imidation of N-methyl benzylamines with phthalimides with excellent regioselectivities is reported for the first time. This operationally simple method offers a valuable tool to obtain str
Controlled Reduction of Carboxamides to Alcohols or Amines by Zinc Hydrides
Ong, Derek Yiren,Yen, Zhihao,Yoshii, Asami,Revillo Imbernon, Julia,Takita, Ryo,Chiba, Shunsuke
supporting information, p. 4992 - 4997 (2019/03/13)
New protocols for controlled reduction of carboxamides to either alcohols or amines were established using a combination of sodium hydride (NaH) and zinc halides (ZnX2). Use of a different halide on ZnX2 dictates the selectivity, wherein the NaH-ZnI2 system delivers alcohols and NaH-ZnCl2 gives amines. Extensive mechanistic studies by experimental and theoretical approaches imply that polymeric zinc hydride (ZnH2)∞ is responsible for alcohol formation, whereas dimeric zinc chloride hydride (H?Zn?Cl)2 is the key species for the production of amines.
Methyl-Selective α-Oxygenation of Tertiary Amines to Formamides by Employing Copper/Moderately Hindered Nitroxyl Radical (DMN-AZADO or 1-Me-AZADO)
Nakai, Satoru,Yatabe, Takafumi,Suzuki, Kosuke,Sasano, Yusuke,Iwabuchi, Yoshiharu,Hasegawa, Jun-ya,Mizuno, Noritaka,Yamaguchi, Kazuya
supporting information, p. 16651 - 16659 (2019/11/11)
Methyl-selective α-oxygenation of tertiary amines is a highly attractive approach for synthesizing formamides while preserving the amine substrate skeletons. Therefore, the development of efficient catalysts that can advance regioselective α-oxygenation at the N-methyl positions using molecular oxygen (O2) as the terminal oxidant is an important subject. In this study, we successfully developed a highly regioselective and efficient aerobic methyl-selective α-oxygenation of tertiary amines by employing a Cu/nitroxyl radical catalyst system. The use of moderately hindered nitroxyl radicals, such as 1,5-dimethyl-9-azanoradamantane N-oxyl (DMN-AZADO) and 1-methyl-2-azaadamanane N-oxyl (1-Me-AZADO), was very important to promote the oxygenation effectively mainly because these N-oxyls have longer life-times than less hindered N-oxyls. Various types of tertiary N-methylamines were selectively converted to the corresponding formamides. A plausible reaction mechanism is also discussed on the basis of experimental evidence, together with DFT calculations. The high regioselectivity of this catalyst system stems from steric restriction of the amine-N-oxyl interactions.
Selective synthesis of mono- and di-methylated amines using methanol and sodium azide as C1 and N1 sources
Chakrabarti, Kaushik,Mishra, Anju,Panja, Dibyajyoti,Paul, Bhaskar,Kundu, Sabuj
supporting information, p. 3339 - 3345 (2018/07/29)
A Ru(ii) complex mediated synthesis of various N,N-dimethyl and N-monomethyl amines from organic azides using methanol as a methylating agent is reported. This methodology was successfully applied for a one-pot reaction of bromide derivatives and sodium azide in methanol. Notably, by controlling the reaction time several N-monomethylated and N,N-dimethylated amines were synthesized selectively. The practical applicability of this tandem process was revealed by preparative scale reactions with different organic azides and synthesis of an anti-vertigo drug betahistine. Several kinetic experiments and DFT studies were carried out to understand the mechanism of this transformation.
Direct Synthesis of N,N-Dimethylated and β-Methyl N,N-Dimethylated amines from nitriles using methanol: Experimental and computational studies
Paul, Bhaskar,Shee, Sujan,Panja, Dibyajyoti,Chakrabarti, Kaushik,Kundu, Sabuj
, p. 2890 - 2896 (2018/04/14)
Direct and selective synthesis of N,N-dimethylated amines from nitriles using methanol as C1 building blocks is reported using an air- and moisture-stable ruthenium complex. Following this process, various aromatic as well as aliphatic nitriles were converted to the corresponding N-methylated amines. Interestingly, tandem C-methylation as well as N-methylation was achieved by introducing multiple methyl groups. The practical aspect of this process was revealed by preparative-scale reactions with different nitriles and the synthesis of anti-allergic drug "avil". Several kinetic experiments and detailed DFT calculations were carried out to understand the mechanism of this process.
