50798-94-2Relevant academic research and scientific papers
Cation Radical-Accelerated Nucleophilic Aromatic Substitution for Amination of Alkoxyarenes
Venditto, Nicholas J.,Nicewicz, David A.
, p. 4817 - 4822 (2020)
Nucleophilic aromatic substitution (SNAr) is a common method for arene functionalization; however, reactions of this type are typically limited to electron-deficient aromatic halides. Herein, we describe a mild, metal-free, cation-radical accelerated nucleophilic aromatic substitution (CRA-SNAr) using a potent, highly oxidizing acridinium photoredox catalyst. Selective substitution of arene C-O bonds on a wide array of aryl ether substrates was shown with a variety of primary amine nucleophiles. Mechanistic evidence is also presented that supports the proposed CRA-SNAr pathway.
Trimethyl Borate-Catalyzed, Solvent-Free Reductive Amination
Ramachandran, P. Veeraraghavan,Choudhary, Shivani,Singh, Aman
, p. 4274 - 4280 (2021/03/09)
Solvent-free reductive amination of aldehydes and ketones with aliphatic and aromatic amines in high-to-excellent yields has been achieved with sub-stoichiometric trimethyl borate as promoter and ammonia borane as reductant.
Photocatalytic one-pot multidirectional N-alkylation over Pt/D-TiO2/Ti3C2: Ti3C2-based short-range directional charge transmission
Jiang, Heyan,Sheng, Meilin,Li, Yue,Kong, Shuzhen,Bian, Fengxia
, (2021/05/17)
Visible-light-induced one-pot, multistep, and chemoselectivity adjustable reactions highlight the economical, sustainable, and green process. Herein, we report Pt nanoparticles dispersed on S and N co-doped titanium dioxide/titanium carbide (MXene) (3%Pt/
A Fe single atom on N,S-doped carbon catalyst for performing N-alkylation of aromatic amines under solvent-free conditions
Lin, Yamei,Lu, Guo-Ping,Shan, Hongbin,Wang, Pengcheng,Zhang, Kai,Zhong, Qin,Zhou, Baojing
supporting information, p. 25128 - 25135 (2021/11/26)
A green and gram-scale strategy has been developed for the synthesis of Fe single atom/N,S-doped carbon catalyst (Fe20-SA@NSC) via the pyrolysis of polyaniline (PAN)-modified Fe,S-doped ZIFs, in which the synthesis of ZIFs can be accomplished in water at room temperature. The as-prepared catalyst exhibits superior activity in the N-alkylation of amines with alcohols via a borrowing strategy under solvent-free conditions (TOF up to 13.9 h-1). Based on the HAADF-STEM and XAFS results, Fe in this material is dispersed as the single-atom Fe1-N4S1 site. According to the experimental and theoretical calculation results, the Fe1-N4S1 site displays a better borrowing hydrogen ability than other Fe sites owing to its higher electron density. In addition, this catalyst has excellent stability and recyclability, and no obvious loss in activity is observed after 7 runs.
Synthesis of NHC-Iridium(III) Complexes Based on N-Iminoimidazolium Ylides and Their Use for the Amine Alkylation by Borrowing Hydrogen Catalysis
Guérin, Vincent,Legault, Claude Y.
supporting information, p. 408 - 417 (2021/02/01)
Anionic NHC ligands recently developed in our group, derived from N-iminoimidazolium ylides, were used to synthesize NHC-iridium(III) complexes. Their catalytic activities were evaluated in the amine alkylation of anilines using borrowing hydrogen catalysis. The high-yielding synthesis of a small library of complexes allowed a rapid screening of the ideal steric bulk of the NHC unit and basicity of the anionic tether for the investigated model reaction. A bulky aromatic N group on the imidazolidene moiety is required to achieve high catalytic activity, and the latter is proportional to the basicity of the anionic group. A selected substrate scope of the reaction was performed, providing fair to excellent yields of the desired alkylated anilines.
Designed pincer ligand supported Co(ii)-based catalysts for dehydrogenative activation of alcohols: Studies onN-alkylation of amines, α-alkylation of ketones and synthesis of quinolines
Singh, Anshu,Maji, Ankur,Joshi, Mayank,Choudhury, Angshuman R.,Ghosh, Kaushik
, p. 8567 - 8587 (2021/06/30)
Base-metal catalystsCo1,Co2andCo3were synthesized from designed pincer ligandsL1,L2andL3having NNN donor atoms respectively.Co1,Co2andCo3were characterized by IR, UV-Vis. and ESI-MS spectroscopic studies. Single crystal X-ray diffraction studies were investigated to authenticate the molecular structures ofCo1andCo3. CatalystsCo1,Co2andCo3were utilized to study the dehydrogenative activation of alcohols forN-alkylation of amines, α-alkylation of ketones and synthesis of quinolines. Under optimized reaction conditions, a broad range of substrates including alcohols, anilines and ketones were exploited. A series of control experiments forN-alkylation of amines, α-alkylation of ketones and synthesis of quinolines were examined to understand the reaction pathway. ESI-MS spectral studies were investigated to characterize cobalt-alkoxide and cobalt-hydride intermediates. Reduction of styrene by evolved hydrogen gas during the reaction was investigated to authenticate the dehydrogenative nature of the catalysts. Probable reaction pathways were proposed forN-alkylation of amines, α-alkylation of ketones and synthesis of quinolines on the basis of control experiments and detection of reaction intermediates.
Mimicking transition metals in borrowing hydrogen from alcohols
Banik, Ananya,Ahmed, Jasimuddin,Sil, Swagata,Mandal, Swadhin K.
, p. 8353 - 8361 (2021/07/02)
Borrowing hydrogen from alcohols, storing it on a catalyst and subsequent transfer of the hydrogen from the catalyst to anin situgenerated imine is the hallmark of a transition metal mediated catalyticN-alkylation of amines. However, such a borrowing hydrogen mechanism with a transition metal free catalytic system which stores hydrogen molecules in the catalyst backbone is yet to be established. Herein, we demonstrate that a phenalenyl ligand can imitate the role of transition metals in storing and transferring hydrogen molecules leading to borrowing hydrogen mediated alkylation of anilines by alcohols including a wide range of substrate scope. A close inspection of the mechanistic pathway by characterizing several intermediates through various spectroscopic techniques, deuterium labelling experiments, and DFT study concluded that the phenalenyl radical based backbone sequentially adds H+, H˙ and an electron through a dearomatization process which are subsequently used as reducing equivalents to the C-N double bond in a catalytic fashion.
Direct electrochemical reductive amination between aldehydes and amines with a H/D-donor solvent
Chen, Lu,Hong, Huanliang,Hu, Jinhui,Huang, Yubing,Li, Yibiao,Liang, Gen,Pu, Suyun,Zhu, Zhongzhi,Zou, Zirong
supporting information, p. 5832 - 5837 (2020/11/03)
A novel electrochemical synthesis protocol has been achieved for reductive amination between aldehydes and amines in undivided cells at room temperature. Under metal-free and external-reductant-free electrolysis conditions, various important secondary amine products are obtained in moderate-to-high yields. Deuterium-labeling experiments have demonstrated that low-toxicity DMSO acts both as a solvent and a H-donor in the reaction. On this basis, various deuterium-labeled products with good-to-excellent D-incorporation have been synthesized by using DMSO-d6 as a solvent. Furthermore, a molecule with GR-antagonistic activity has been synthesized through further sulfonylation.
Transfer Hydrogenation of Ketones and Imines with Methanol under Base-Free Conditions Catalyzed by an Anionic Metal-Ligand Bifunctional Iridium Catalyst
Han, Xingyou,Li, Feng,Liu, Peng,Wang, Rongzhou,Xu, Jing
, p. 2242 - 2249 (2020/03/13)
An anionic iridium complex [Cp*Ir(2,2′-bpyO)(OH)][Na] was found to be a general and highly efficient catalyst for transfer hydrogenation of ketones and imines with methanol under base-free conditions. Readily reducible or labile substituents, such as nitro, cyano, and ester groups, were tolerated under present reaction conditions. Notably, this study exhibits the unique potential of anionic metal-ligand bifunctional iridium catalysts for transfer hydrogenation with methanol as a hydrogen source.
Dialkylterphenyl Phosphine-Based Palladium Precatalysts for Efficient Aryl Amination of N-Nucleophiles
Rama, Raquel J.,Maya, Celia,Nicasio, M. Carmen
supporting information, p. 1064 - 1073 (2020/01/25)
A series of 2-aminobiphenyl palladacycles supported by dialkylterphenyl phosphines, PR2Ar′ (R=Me, Et, iPr, Cyp (cyclopentyl), Ar′=ArDipp2, ArXyl2f, Dipp (2,6-C6H3-(2,6-C6H3-(CHMe2)2)2), Xyl=xylyl) have been prepared and structurally characterized. Neutral palladacycles were obtained with less bulky terphenyl phosphines (i.e., Me and Et substituents) whereas the largest phosphines provided cationic palladacycles in which the phosphines adopted a bidentate hemilabile k1-P,η1-Carene coordination mode. The influence of the ligand structure on the catalytic performance of these Pd precatalysts was evaluated in aryl amination reactions. Cationic complexes bearing the phosphines PiPr2ArXyl2 and PCyp2ArXyl2 were the most active of the series. These precatalysts have demonstrated a high versatility and efficiency in the coupling of a variety of nitrogen nucleophiles, including secondary amines, alkyl amines, anilines, and indoles, with electronically deactivated and ortho-substituted aryl chlorides at low catalyst loadings (0.25–0.75 mol % Pd) and without excess ligand.
