4965-33-7Relevant articles and documents
Acid-Activatable Michael-Type Fluorescent Probes for Thiols and for Labeling Lysosomes in Live Cells
Dai, Chun-Guang,Du, Xiao-Jiao,Song, Qin-Hua
, p. 12088 - 12099 (2015)
A Michael addition is usually taken as a base-catalyzed reaction. Most fluorescent probes have been designed to detect thiols in slightly alkaline solutions (pH 7-9). The sensing reactions of almost all Michael-type fluorescent probes for thiols are faster in a high pH solution than in a low pH solution. In this work, we synthesized a series of 7-substituted 2-(quinolin-2-ylmethylene)malonic acids (QMAs, substituents: NEt2, OH, H, Cl, or NO2) and their ethyl esters (QMEs) as Michael-type fluorescent probes for thiols. The sensing reactions of QMAs and QMEs occur in distinct pH ranges, pH 7 for QMEs. On the basis of experimental and theoretic studies, we have clarified the distinct pH effects on the sensing reactivity between QMAs and QMEs and demonstrated that two QMAs (NEt2, OH) are highly sensitive and selective fluorescent probes for thiols in acidic solutions (pH 7) and promising dyes that can label lysosomes in live cells.
Visible light mediated selective oxidation of alcohols and oxidative dehydrogenation of N-heterocycles using scalable and reusable La-doped NiWO4nanoparticles
Abinaya, R.,Balasubramaniam, K. K.,Baskar, B.,Divya, P.,Mani Rahulan, K.,Rahman, Abdul,Sridhar, R.,Srinath, S.
, p. 5990 - 6007 (2021/08/24)
Visible light-mediated selective and efficient oxidation of various primary/secondary benzyl alcohols to aldehydes/ketones and oxidative dehydrogenation (ODH) of partially saturated heterocycles using a scalable and reusable heterogeneous photoredox catalyst in aqueous medium are described. A systematic study led to a selective synthesis of aldehydes under an argon atmosphere while the ODH of partially saturated heterocycles under an oxygen atmosphere resulted in very good to excellent yields. The methodology is atom economical and exhibits excellent tolerance towards various functional groups, and broad substrate scope. Furthermore, a one-pot procedure was developed for the sequential oxidation of benzyl alcohols and heteroaryl carbinols followed by the Pictet-Spengler cyclization and then aromatization to obtain the β-carbolines in high isolated yields. This methodology was found to be suitable for scale up and reusability. To the best of our knowledge, this is the first report on the oxidation of structurally diverse aryl carbinols and ODH of partially saturated N-heterocycles using a recyclable and heterogeneous photoredox catalyst under environmentally friendly conditions.
Preparation method of 7-chloroquinaldine with recyclable raw materials
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Paragraph 0028-0043, (2021/11/03)
The invention relates to the technical field of organic synthesis, in particular to a preparation method of 7-chloroquinaldine with recyclable raw materials, which comprises the following steps: taking 7-chloroquinaldine and crotonaldehyde as raw materials, and carrying out skraup reaction under the action of 3-nitrochlorobenzene to synthesize the 7-chloroquinaldine. In the preparation method provided by the invention, the 3-nitrochlorobenzene can be subjected to reduction reaction to be converted into the raw material m-chloroaniline, so that the raw material can be recycled, the utilization rate of the raw material is greatly improved, the preparation process is simplified, the emission of three wastes is low, and the target product is high in yield and purity.
Reusable, homogeneous water soluble photoredox catalyzed oxidative dehydrogenation of N-heterocycles in a biphasic system: Application to the synthesis of biologically active natural products
Abinaya, R.,Baskar, B.,Mariappan, M.,Prasanth, Arun,Sridhar, R.,Srinath, S.
, p. 2575 - 2587 (2020/05/13)
Herein, a simple and efficient method for the oxidative dehydrogenation (ODH) of tetrahydro-β-carbolines, indolines and tetrahydro-(iso)quinolines is described using a reusable, homogeneous cobalt-phthalocyanine photoredox catalyst in a biphasic medium. A biphasic system offers an advantage of easy separation of the product and an efficient reusability of the homogeneous photoredox catalyst. Also, the current system significantly helps to overcome the solubility issue of the substrate and catalyst at room temperature. Its potential applications to organic transformations are demonstrated by the synthesis of various biologically active N-heterocycles such as indoles, (iso)quinolines and β-carbolines and natural products such as eudistomin U, norharmane, and harmane and precursors to perlolyrine and flazin. Without isolation and purification, the catalyst solution can be reused up to 5 times with almost comparable reactivity. Furthermore, the efficiency of the reaction was demonstrated on a gram scale. To the best of our knowledge, this is the first report on ODH reactions using a non noble, reusable and homogeneous cobalt photoredox catalyst under environmentally friendly conditions.
Nickel-Catalyzed Dehydrogenation of N-Heterocycles Using Molecular Oxygen
Banerjee, Debasis,Bera, Atanu,Bera, Sourajit
supporting information, (2020/09/02)
Herein, an efficient and selective nickel-catalyzed dehydrogenation of five- and six-membered N-heterocycles is presented. The transformation occurs in the presence of alkyl, alkoxy, chloro, free hydroxyl and primary amine, internal and terminal olefin, trifluoromethyl, and ester functional groups. Synthesis of an important ligand and the antimalarial drug quinine is demonstrated. Mechanistic studies revealed that the cyclic imine serves as the key intermediate for this stepwise transformation.
Synthetic method 7-chloroquinaldine (by machine translation)
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Paragraph 0035; 0044-0045; 0050; 0059-0061; 0070-0072, (2020/04/17)
The process 7 - comprises the following steps, dissolving, 1 with 3 - (3 - chlorine-anilino) - butyraldehyde as a raw material, in a solvent to obtain, chloroquinaldine A under the action of an acidic catalyst 3 - (3 - and dehydrating the intermediate) - into a reaction solvent, to carry out an oxidation reaction 1;2 to obtain the intermediate 1 of the intermediate compound B as the reaction solution 2;3 and adding an oxidizing agent to the intermediate 2 as a raw material, to carry out dehydration reaction under the action of an acidic catalyst solution.]. The reaction, is carried out under the action of the acidic catalyst solution of the intermediate body . 5 - The method reduces, 7 - chloroquinaldine. (by machine translation)
Corrigendum: Organo-Photoredox Catalyzed Oxidative Dehydrogenation of N-Heterocycles (Chemistry - A European Journal, (2017), 23, 57, (14167-14172), 10.1002/chem.201703642)
Sahoo, Manoj K.,Jaiswal, Garima,Rana, Jagannath,Balaraman, Ekambaram
, p. 7038 - 7038 (2019/05/17)
The authors have been alerted to an error that was unfortunately missed at the time of publication. Table was duplicated with Table 4. The correct version of Table 2 is shown below. The authors apologise for any inconvenience caused. Organo-photoredox catalyzed oxidative dehydrogenation of tetrahydroquinolines (THQ).[a,b] (Table presented.) [a] Reaction conditions: 1 (0.5 mmol), rose bengal (1.0 mol %), N,N-dimethylacetamide (2.0 mL), open air atmosphere under visible-light irradiation at room temperature for 24 h. [b] Isolated yields. [c] 0.1 mol % of photoredox catalyst for 28 h.
Room temperature catalytic dehydrogenation of cyclic amines with the liberation of H2 using water as a solvent
Sahoo, Manoj K.,Balaraman, Ekambaram
supporting information, p. 2119 - 2128 (2019/04/26)
Catalytic dehydrogenation of cyclic amines, in particular partially saturated N-heterocycles to N-heterocyclic arenes, with the removal of molecular hydrogen as the sole byproduct in water is reported. This dehydrogenation reaction proceeds smoothly under very mild and benign conditions and operates at room temperature. This distinctive reactivity has been achieved under dual catalytic conditions by merging the visible-light active [Ru(bpy)3]2+ as the photoredox catalyst and a newly synthesized cobalt complex as the proton-reduction catalyst. A detailed mechanistic study (control experiments, electrochemical studies, UV-visible experiments) is presented for the present dual catalysis.
Deracemization of Phenyl-Substituted 2-Methyl-1,2,3,4-Tetrahydroquinolines by a Recombinant Monoamine Oxidase from Pseudomonas monteilii ZMU-T01
Deng, Guozhong,Wan, Nanwei,Qin, Lei,Cui, Baodong,An, Miao,Han, Wenyong,Chen, Yongzheng
, p. 2374 - 2377 (2018/04/19)
A monoamine oxidase (MAO5) from Pseudomonas monteilii ZMU-T01 was first heterologously expressed in Escherichia coli BL21(DE3) and then used as a biocatalyst for the deracemization of racemic 2-methyl-1,2,3,4-tetrahdroquinoline derivatives to yield the unreacted R enantiomer with up to >99 % ee. Sequence alignment revealed that MAO5 shared 14.7 % identity toward the well-studied monoamine oxidase (MAO-N).
Synthesis method of 7-chloroquinaldine
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Paragraph 0010; 0012-0030, (2018/11/27)
The invention discloses a synthesis method of 7-chloroquinaldine. 2-nitrotoluene, SiO2-HEPIMBr, m-chloroaniline, crotonaldehyde, TEOS, 2-bromoethanol, imidazole and 3-chloropropyltriethoxysilane are taken as main raw materials. According to the synthesis process, m-chloroaniline and crotonaldehyde are subjected to Skraup reaction under action of an immobilized ion catalyst SiO2-HEPIMBr, and 7-chloroquinaldine is obtained. SiO2 immobilized hydroxyl ionic liquid HEPIMBr is prepared with a grafting method, in the reaction, few by-products are produced and no 5-isomer is produced, so that the separation and purification process is reduced, purity of a product is improved, yield of the product is increased, and higher market competitiveness is achieved.
