41833-57-2Relevant academic research and scientific papers
Halogenated method of aromatic compound
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Paragraph 0058-0061, (2021/11/10)
The invention belongs to the field of organic synthesis, and particularly relates to synthesis of aromatic halogens, in particular to arylamine. The invention discloses a synthesis method of a corresponding ortho-halogenated product from aromatic compounds such as carbazole and phenol. The method comprises the following steps: adding a metal sulfonate salt catalyst, aromatic amine, carbazole, phenol and other hydrogen - heteroatom-containing aromatic compound reaction substrates, a halogenation reagent and a reaction solvent at a specific reaction temperature. After the drying agent is dried, the yield of the reaction product and the nuclear magnetic characterization determining structure are determined by column chromatography. The reaction product yield is determined by gas chromatography. By adopting the method, under the cheap metal salt catalyst, a plurality of ortho-substituted brominated and chloro products can be obtained with moderate to excellent yield.
A green and convenient approach for the one-pot solvent-free synthesis of coumarins and β-amino carbonyl compounds using Lewis acid grafted sulfonated carbon@titania composite
Kour, Manmeet,Paul, Satya
, p. 327 - 337 (2017/02/10)
Abstract: This paper reports an efficient protocol for the synthesis of coumarins via Pechmann reaction, and β-amino carbonyl compounds via aza-Michael reaction using catalytic amount of solid Lewis acid catalyst, C@TiO2–SO3–SbCl2. Six different catalysts were prepared by covalent immobilization of homogeneous Lewis acids onto sulfonated carbon@titania composite derived from amorphous carbon and nano-titania. Among various catalysts tested, C@TiO2–SO3–SbCl2 showed superior catalytic activity. The catalyst could be recycled without significant loss of its catalytic activity and demonstrated versatile catalysis for a wide range of substrates. Graphical abstract: [Figure not available: see fulltext.]
Polymer coated magnetically separable organocatalyst for C[sbnd]N bond formation via aza-Michael addition
Panwar, Vineeta,Ray, Siddharth S.,Jain, Suman L.
, p. 5026 - 5032 (2016/11/02)
A polyacrylamide coated magnetite (PAM@MNP) catalyst was synthesized by following a two step approach involving the reaction of magnetite (Fe3O4) particles with coupling agent 3-(trimethoxysilyl)propyl methacrylate followed by grafting of acrylamide and subsequent polymerization via surface initiated radical polymerization technique. The synthesized organocatalyst was used for a one-pot aza-Michael addition reaction of amines with electron deficient alkenes to give β-amino carbonyls. The magnetic properties of the synthesized organocatalyst provide it a facile recovery by external magnet which eliminates the problems arising during catalyst separation by conventional filtration.
Synthesis, Characterization and Catalytic Application of MCM 41 Supported Phenanthrolinium Dibromide Catalyst for Aza-Michael Addition Reaction in Aqueous Medium
Hosseinzadeh, Rahman,Aghili, Nora,Tajbakhsh, Mahmood
, p. 1194 - 1203 (2016/07/06)
Abstract: MCM-41 immobilized phenanthrolinium dibromide (phen-MCM-Br2) was easily prepared and applied as an efficient heterogeneous catalyst for aza-Michael addition of aromatic amines to α,β-unsaturated nitriles and nitro compounds in water. The catalyst was characterized by CHN, TGA, FT-IR, SEM, EDAX, XRD, BET, and TEM. It could be simply recovered and reused several times without significant loss of catalytic activity. Graphical Abstract: [Figure not available: see fulltext.]
Boric acid/glycerol as an efficient catalyst for synthesis of thiomorpholine 1,1-dioxide by double michael addition reaction in water
Halimehjnai, Azim Ziyaei,Hosseyni, Seyedmorteza,Gholami, Hadi,Hashemi, Mohammed M.
, p. 191 - 197,7 (2020/09/02)
Thiomorpholine 1,1-dioxides were prepared with double Michael addition reaction of aromatic amines to divinyl sulfone catalyzed by boric acid/glycerol in water. This catalyst system was also used for the Michael addition reaction of aromatic amines to electron-deficient alkenes. The reaction is simple and green and gives good to excellent yields.
Selective and nonselective aza-michael additions catalyzed by a chiral zirconium bis-diketiminate complex
El-Zoghbi, Ibrahim,Kebdani, Myriam,Whitehorne, Todd J. J.,Schaper, Frank
, p. 6986 - 6995 (2014/01/06)
Reaction of the chiral bis-diketiminate complex rac- or (R,R)-C 6H10(nacnacXyl)2ZrCl2 with AgOTf yielded the corresponding bis-triflate complex. The complex geometry changes from distorted octahedral in the dichloride complex to a pseudotetrahedral coordination involving π coordination of the diketiminate ligands. The bis-triflate complex is highly active for aza-Michael additions with turnover frequencies of 20000/h for the addition of morpholine to acrylonitrile and 1000/h for the addition of morpholine to methacrylonitrile. The enantioselectivities of the latter reaction in various solvents were low, never surpassing 19% ee. The reaction is first-order in olefin concentration and second order in amine concentration, which is explained by its participation as a base in the reaction mechanism. The presence of catalytic amounts of triethylamine slightly increases the observed rate constants and reduces the reaction order in amine to first order. Other activated alkenes such as methacrylonitrile, crotonitrile, methyl acrylate, and cyclohexenone can be employed, but no reactivity is observed toward styrene or vinyl ethers. Primary amines, secondary amines, and anilines can be employed as nucleophiles with activities correlating with their nucleophilicity, but the catalyst is unstable in the presence of alcohols.
Lithium tetrafluoroborate catalyzed highly efficient inter- and intramolecular aza-Michael addition with aromatic amines
Lad,Kulkarni,Desai,Wadgaonkar
experimental part, p. 1059 - 1064 (2012/03/11)
Lithium tetrafluoroborate has been demonstrated for the first time to be an efficient catalyst in intermolecular aza-Michael addition aromatic amines to electron deficient alkenes. Suitability of the same catalyst in intramolecular aza-Michael addition leading 2-aryl-2,3-dihydroquinolin-4(1H) ones has also been described.
Hydroamination and alcoholysis of acrylonitrile promoted by the pincer complex {κP,κC,κP-2,6- (Ph2PO)2C6H3}Ni(OSO 2CF3)
Salah, Abderrahmen B.,Offenstein, Caroline,Zargarian, Davit
experimental part, p. 5352 - 5364 (2011/12/13)
This report describes the catalytic activity of the pincer-type complex {κP,κC,κP-2,6-(Ph 2PO)2C6H3}Ni(OSO2CF 3) (1) in the anti-Markovnikov addition of aliphatic and aromatic amines and alcohols to acrylonitrile, crotonitrile, and methacrylonitrile. The influence of additives on the catalytic activities was investigated, and it was found that substoichiometric quantities of water promoted the C-N bond forming reactions catalyzed by 1, especially the reactions involving aromatic amines; in comparison, NEt3 had a less dramatic impact. The opposite pattern was observed for the alcoholysis of acrylonitrile promoted by 1: water had no beneficial effect on these reactions, while NEt3 proved to be a potent promoter. Another important difference between these reactions is that hydroamination works better with more nucleophilic amines, whereas the alcoholysis reactions work well with ArOH, CF3CH2OH, and ArCH2OH but not at all with the more nucleophilic aliphatic alcohols methanol, ethanol, and 2-propanol. Both hydroamination and alcoholysis proceed much better with acrylonitrile in comparison to its Me-substituted derivatives crotonitrile and methacrylonitrile. Under optimized conditions, precatalyst 1 promotes conjugate additions to acrylonitrile with catalytic turnover numbers of up to 100 (hydroamination) or higher (alcoholysis). Spectroscopic studies have established that the main Ni-containing species in the hydroamination reactions is a cationic adduct in which the olefinic substrate is bound to the Ni center via its nitrile moiety; this binding activates the double bond toward an outer-sphere nucleophilic attack by the amine (Michael addition). The solid-state structures of the cationic nitrile adducts [{κP, κC,κP-2,6-(Ph2PO)2C 6H3}Ni(NCR)][OSO2CF3] (R = Me (2a), CH2CH2N(H)Ph (2e)), which can be regarded as model complexes for the species involved in the hydroamination catalysis, have been elucidated. Also reported are the solid-state structures of the charge-neutral compound {κP,κC,κP-2,6-(i- Pr2PO)2C6H3}Ni(OSO 2CF3) and an octahedral Ni(II) species resulting from the aerobic/hydrolytic oxidation of 1.
Squaric acid as an impressive organocatalyst for Michael addition in water
Azizi, Najmadin,Saki, Elham,Edrisi, Mahtab
experimental part, p. 973 - 977 (2012/05/20)
A simple, green, and environmentally benign protocol for squaric acid (5 mg) catalyst conjugate addition of aromatic amines and thiols to unsaturated carbonyl compounds in water in good to excellent yields is developed. The advantages of low sensitivity toward moisture and oxygen, high tolerance of different functional groups, green reaction media and efficient recyclability make this organocatalyst suitable for both laboratory and industrial scale synthesis of β-substituted carbonyls under very mild conditions.
An effective aza-michael addition of aromatic amines to electron-deficient alkenes in alkaline Al2O3
Ai, Xin,Wang, Xin,Liu, Jin-Ming,Ge, Ze-Mei,Cheng, Tie-Ming,Li, Run-Tao
experimental part, p. 5373 - 5377 (2010/08/06)
Aza-Michael addition of aromatic or aliphatic amines with various electron-deficient alkenes was performed using alkaline Al2O 3 as solid media at room temperature afforded the corresponding Michael addition products in good to excellent yields.The alkaline Al 2O3 can be easily recovered and reused.
