605-03-8Relevant academic research and scientific papers
Xantphos-Capped Pd(II) and Pt(II) Macrocycles of Aryldithiolates: Structural Variation and Catalysis in C-C Coupling Reaction
Mane, Pravin A.,Dey, Sandip,Pathak, Arup Kumar,Kumar, Mukesh,Bhuvanesh, Nattamai
, p. 2965 - 2978 (2019)
The self-assembly of Xantphos-capped M(OTf)2 (M = cis-[M′(Xantphos)]2+ M′ = Pd, Pt) with bridging ligands 1,4-benezenedithiol or 4,4′-biphenyldithiol has been investigated. The reactions have yielded complexes [M{S(C6H4)nSH}]2(OTf)2 (I) and [M2{S(C6H4)nS}]2(OTf)4 (II) (n = 1 or 2). The equilibrium between I and II has been established in platinum complexes for n = 2, whereas the analogous Pd complex exclusively exist as II. These results are different from our previously reported dppe or triethyl phosphine-capped complexes which showed only type II. The same reaction with 1,3-benezenedithiol lead to the complex [M2(SC6H4SSC6H4S)](OTf)2 (III), containing a S-S bond between two thiolate ligands, formed via a complex of type I in solution. Characterization of the complexes was accomplished by NMR spectroscopy, UV-vis spectroscopy and mass spectrometry, and X-ray crystallography. Density functional calculations were performed to estimate the relative stability of three types of complexes. The palladium complexes are excellent catalysts in Suzuki C-C cross coupling reactions under mild conditions, and can be reused eight times without losing significant yield. The activity of the Pd catalysts derived from three dithiol ligand follows opposite trend of the stability as III > II > I. The comparative catalytic activity of the tetranuclear Pd complexes (II) of bis-phosphines of varied bite angles, including the structurally characterized [Pd2(dppf)2(SC12H8S)]2(OTf)4 has also been demonstrated.
Minisci-Type Alkylation of N-Heteroarenes by N-(Acyloxy)phthalimide Esters Mediated by a Hantzsch Ester and Blue LED Light
Kyne, Sara Helen,Li, Jiacheng,Siang Tan, Suan,Wai Hong Chan, Philip
supporting information, (2022/01/11)
A synthetic method that enables the Hantzsch ester-mediated Minisci-type C2-alkylation of quinolines, isoquinolines and pyridines by N-(acyloxy)phthalimide esters (NHPI) under blue LED (light emitting diode) light (456 nm) is described. Achieved under mild reaction conditions at room temperature, the metal-free synthetic protocol was shown to be applicable to primary, secondary and tertiary NHPIs to give the alkylated N-heterocyclic products in yields of 21–99%. On introducing a chiral phosphoric acid, an asymmetric version of the reaction was also realised and provided product enantiomeric excess (ee) values of 53–99%. The reaction mechanism was delineated to involve excitation of an electron-donor acceptor (EDA) complex, formed from weak electrostatic interactions between the Hantzsch ester and NHPI, which generates the posited radical species of the redox active ester that undergoes addition to the N-heterocycle.
Synthesis of Quinolines via the Metal-free Visible-Light-Mediated Radical Azidation of Cyclopropenes
Smyrnov, Vladyslav,Muriel, Bastian,Waser, Jerome
, p. 5435 - 5439 (2021/07/21)
We report the synthesis of quinolines using cyclopropenes and an azidobenziodazolone (ABZ) hypervalent iodine reagent as an azide radical source under visible-light irradiation. Multisubstituted quinoline products were obtained in 34-81% yield. The reaction was most efficient for 3-trifluoromethylcyclopropenes, affording valuable 4-trifluoromethylquinolines. The transformation probably proceeds through the cyclization of an iminyl radical formed by the addition of the azide radical on the cyclopropene double bond, followed by ring-opening and fragmentation.
Method for preparing 2 -arylquinoline from 4 -amino diaryl methanol
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Paragraph 0041-0050, (2021/10/27)
The invention discloses a method for preparing 2 - arylquinoline from 4 -amino diaryl methanol, wherein 2 -aminodiarylmethanol is heated and converted into DMSO arylquinoline compounds under the action of alkali under an oxygen-containing atmosphere in a mixed solution of formaldehyde and 4 . In 4 -arylquinoline compound structure prepared by the method 2-position carbon atoms are provided DMSO, 3-bit carbon atoms are provided by formaldehyde, and all other atoms in the quinoline compound structure are provided by the raw material o-amino aryl methanol. The method for synthesizing 4 - arylquinoline has the advantages of wide raw material sources, environmental friendliness, low price and simple operation, and is beneficial to industrial production.
Unexpected Annulation between 2-Aminobenzyl Alcohols and Benzaldehydes in the Presence of DMSO: Regioselective Synthesis of Substituted Quinolines
Yang, Tonglin,Nie, Zhi-Wen,Su, Miao-Dong,Li, Hui,Luo, Wei-Ping,Liu, Qiang,Guo, Can-Cheng
, p. 15228 - 15241 (2021/10/25)
An unexpected annulation among 2-aminobenzyl alcohols, benzaldehydes, and DMSO to quinolines has been disclosed. For the reported annulation between 2-aminobenzyl alcohols and benzaldehydes, the change of the solvent from toluene to DMSO led to the change of the product from the diheteroatomic cyclic benzoxazines to monoheteroatomic cyclic quinolines. This annulation can be used to synthesize regioselectively different substituted quinolines by the choice of different 2-amino alcohols, aldehydes, and sulfoxides as substrates. Interestingly, introducing substituent groups to the α-position of sulfoxides resulted in the interchange of the positions between benzaldehydes and sulfoxides in the product quinolines. On the basis of the control experiments and literatures, a plausible mechanism for this annulation was proposed.
PEG-400 as a carbon synthon: Highly selective synthesis of quinolines and methylquinolines under metal-free conditions
Ding, Chengcheng,Feng, Kaili,Li, Shichen,Ma, Chen
supporting information, p. 5542 - 5548 (2021/08/16)
A metal-free, peroxide-free, and efficient procedure for the highly selective synthesis of quinolines and methylquinolines was reported. The main feature of this method was that the same substrate can produce quinolines and methylquinolines, respectively, under different reaction conditions. PEG-400 was used as both a reactant and solvent in this reaction. The utility of the designed procedure was also demonstrated by the derivatization of the products to bioactive compounds. This journal is
Synthesis of 4-substituted-1,2-dihydroquinolines by means of gold-catalyzed intramolecular hydroarylation reaction of n-ethoxycarbonyl-n-propargylanilines
Arcadi, Antonio,Calcaterra, Andrea,Fabrizi, Giancarlo,Fochetti, Andrea,Goggiamani, Antonella,Iazzetti, Antonia,Marrone, Federico,Marsicano, Vincenzo,Mazzoccanti, Giulia,Serraiocco, Andrea
, (2021/06/21)
An alternative Au(I)-catalyzed synthetic route to functionalized 1,2-dihydroquinolines is reported. This novel approach is based on the use of N-ethoxycarbonyl protected-Npropargylanilines as building blocks that rapidly undergo the IMHA reaction affording the 6-endo cyclization product in good to high yields. In the presence of N-ethoxycarbonyl-N-propargyl-metasubstituted anilines, the regiodivergent cyclization at the ortho-/para-position is achieved by the means of catalyst fine tuning.
Copper-mediated formal [5+1] annulation of 2-vinylanilines and glyoxylic acid: A facile approach for the synthesis of 4-arylated quinolines
Xiang, Yunyu,Luo, Puying,Hao, Tianxin,Xiong, Weikang,Song, Xiaolin,Ding, Qiuping
, (2020/12/13)
A copper-mediated formal [5 + 1] oxidative annulation of 2-vinylanilines and glyoxylic acid to 4-arylated quinolines was developed. A series of 4-arylated quinoline derivatives were obtained in good to excellent yields. This protocol could be carried out efficiently on gram scale. The transformation probably underwent nucleophilic addition/6π electrocyclization/oxidative aromatization and the elimination of CO2 cascade processes.
Iron(II)-Catalyzed Aerobic Biomimetic Oxidation of N-Heterocycles
Manna, Srimanta,Kong, Wei-Jun,B?ckvall, Jan-E.
supporting information, p. 13725 - 13729 (2021/09/08)
Herein, an iron(II)-catalyzed biomimetic oxidation of N-heterocycles under aerobic conditions is described. The dehydrogenation process, involving several electron-transfer steps, is inspired by oxidations occurring in the respiratory chain. An environmentally friendly and inexpensive iron catalyst together with a hydroquinone/cobalt Schiff base hybrid catalyst as electron-transfer mediator were used for the substrate-selective dehydrogenation reaction of various N-heterocycles. The method shows a broad substrate scope and delivers important heterocycles in good-to-excellent yields.
Time-Resolved EPR Revealed the Formation, Structure, and Reactivity of N -Centered Radicals in an Electrochemical C(sp3)-H Arylation Reaction
Alhumade, Hesham,Gao, Renfei,Huang, Cunlong,Lei, Aiwen,Liu, Yichang,Liu, Zhao,Qi, Xiaotian,Shi, Biyin,Wang, Shengchun
supporting information, p. 20863 - 20872 (2021/12/14)
Electrochemical synthesis has been rapidly developed over the past few years, while a vast majority of the reactions proceed through a radical pathway. Understanding the properties of radical intermediates is crucial in the mechanistic study of electroche
