scholarly journals Synthesis of interesting β-nitrohydrazides through a thiourea organocatalysed aza-Michael addition

RSC Advances ◽  
2014 ◽  
Vol 4 (19) ◽  
pp. 9856-9865 ◽  
Author(s):  
Ana Alcaine ◽  
Eugenia Marqués-López ◽  
Raquel P. Herrera
Keyword(s):  
Michael Addition ◽  
Target Product ◽  
First Time

The synthesis of interesting β-nitrohydrazides, as the target product of our reaction, is reached for the first time under organocatalytic enantioselective conditions.

Catalyst-Free One-Pot Synthesis of Novel Heteroarylamine Substituted Furo[3,2-c]coumarins

Synlett ◽  
2018 ◽  
Vol 29 (12) ◽  
pp. 1589-1592 ◽  
Author(s):  
Abolfazl Olyaei ◽  
Mahnaz Saraei ◽  
Reyhaneh Khoeiniha
Keyword(s):  
Michael Addition ◽  
Aldol Condensation ◽  
Ring Closure ◽  
Dehydration Reaction ◽  
One Pot ◽  
Catalyst Free ◽  
One Pot Synthesis ◽  
Tandem Process ◽  
First Time

A high-yielding cyclocondensation of 4-hydroxycoumarin, phenylglyoxal monohydrate, and heteroarylamines proceeds without catalysis, which gives novel functionalized furo[3,2-c]coumarins and heteroarylamino alkylation of coumarin products in acetonitrile under reflux, is reported for the first time. This tandem process involves sequentially an aldol condensation, Michael addition, a ring closure, and dehydration reaction.

Ti-Al-Nb Material for High-Temperature Applications: Combustion Synthesis from Oxide Raw Materials

2017 ◽  
Vol 746 ◽  
pp. 262-266
Author(s):  
D.E. Andreev ◽  
V.I. Yukhvid ◽  
Denis M. Ikornikov ◽  
Vladimir N. Sanin
Keyword(s):  
High Temperature ◽  
Combustion Synthesis ◽  
Raw Materials ◽  
High Gravity ◽  
Target Product ◽  
Oxide Materials ◽  
Centrifugal Shs ◽  
First Time ◽  
Metallic Impurities ◽  
Temperature Applications

This work is focused on preparation of Nb-doped Ti–Al material (Ti–29.3Al–17.6Nb wt %) by centrifugal SHS. Results of studying of combustion and synthesis regularities of intermetallic material on γ-TiAl base from oxide materials under high gravity are presented in the article. For the first time is used a reduction mixture on Al/Ca base which markedly increases the yield of Ti–Al–Nb and decreases the amount of non-metallic impurities (oxygen, nitrogen, carbon) in target product.

A concentration dependent auto-relay-recognition by the same analyte: a dual fluorescence switch-on by hydrogen sulfide via Michael addition followed by reduction and staining for bio-activity

2016 ◽  
Vol 14 (2) ◽  
pp. 570-576 ◽  
Author(s):  
Avijit Kumar Das ◽  
Shyamaprosad Goswami ◽  
Gorachand Dutta ◽  
Sibaprasad Maity ◽  
Tarun kanti Mandal ◽  
...  
Keyword(s):  
Hydrogen Sulfide ◽  
Michael Addition ◽  
Dual Role ◽  
Dual Fluorescence ◽  
Fluorescence Switch ◽  
First Time

H2S is shown, for the first time, to play an extraordinary dual role due to its nucleophilicity and reducing property with a single chemosensor.

scholarly journals A novel and practical synthesis of iclaprim

2020 ◽  
Author(s):  
Weiyuan Liu ◽  
Liang Chen ◽  
Jing Pan ◽  
Ting Zhou ◽  
Kuaile Lin ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Acetic Anhydride ◽  
Michael Addition ◽  
Knoevenagel Condensation ◽  
Total Yield ◽  
Buffer System ◽  
Facile Synthesis ◽  
Practical Synthesis ◽  
First Time ◽  
Amino Protection

A novel and facile synthesis of iclaprim was reported. Started from Trimethoprim (TMP), the amino-protection and Friedel-Crafts acetylation with acetic anhydride were simultaneously completed in CH2Cl2 with SnCl4 as catalyst. The Knoevenagel condensation of 2,4-diamino-5-(2-acetyl-3-hydroxy-4,5-dimethoxybenzyl)pyrimidine with cyclopropyl carboxaldehyde followed by the intramolecular Michael addition in the buffer system (pyrrolidine and acetic acid) installed the key framework (chromanone 13). The dehydration was catalyzed by H2SO4 so that the formation of 5-cyclopropyl-2,3-dimethoxy-4,5,6,6a,7,12-hexahydronaphtho[1,8-bc]pyrimido[5,4-f]azepin-9-amine, an impurity of iclaprim reported at the first time, could be minimized. In the end, iclaprim was obtained in a total yield of 21%.

scholarly journals Investigation of the catalуtic activitу of K2CO3 in the carboxуlation reaction of phenol with sodium ethуl carbonate

2019 ◽  
pp. 24-35
Author(s):  
Khakim Suerbaev ◽  
Kairzhan Shalmagambetov ◽  
Gulbanu Zhaksylykova ◽  
Nurbolat Kudaibergenov ◽  
Madina Kozhakhmet
Keyword(s):  
Salicylic Acid ◽  
Catalytic Activity ◽  
Synthesis Method ◽  
Alternative Methods ◽  
Growth Promoter ◽  
Target Product ◽  
Sodium Ethyl ◽  
Method Of Production ◽  
First Time ◽  
Sodium Ethyl Carbonate

The catalуtic activitу of К2СО3 in the carboxуlation reaction of phenol with sodium ethуl carbonate has been investigated. The aim of the research was to develop a new efficient method for producing salicylic acid which is widely used in pharmaceuticals and other type preparations, also used in agriculture as an effective plant growth promoter. The most widespread synthesis method of salicylic acid is the Kolbe-Schmitt of phenol carboxylation, but it has a number of serious disadvantages. One of the alternative methods is the use of alkali metal salts of mono ethers of the carbonic acids as carboxylating agents in the carboxylation of phenol. In order to improve the method of production of salicylic acid, the catalytic activity of the К2СО3 catalyst at the carboxylation of phenol with sodium ethyl carbonate was studied for the first time. The effect of the process parameters (temperature, pressure, reaction time, ratio of catalyst to carboxylating agent) on the yield of the target product was studied. It was found optimal conditions: T=160°C, PCO2=10 atm, τ=7(4+3) h, [К2СО3]:[SEC]=0.07:1 at which the yield of the target product was 80%. The yields of the target product at phenol carboxylation with sodium ethyl carbonate in the presence and without K2CO3 were determined. It was found that К2СО3 shows the catalytic activity during carboxylation reaction.

Direct organocatalytic asymmetric Michael reaction of fluorine hemiaminal-type nucleophile to 4-nitro-5-styrylisoxazoles

2020 ◽  
Vol 7 (11) ◽  
pp. 1343-1348
Author(s):  
Luyao Li ◽  
Bo Zhu ◽  
Huihui Fan ◽  
Zhiyong Jiang ◽  
Junbiao Chang
Keyword(s):  
Michael Addition ◽  
Michael Reaction ◽  
Addition Reaction ◽  
Michael Addition Reaction ◽  
Asymmetric Michael Addition ◽  
Asymmetric Michael Reaction ◽  
First Time

Herein, we report a chiral bifunctional thiourea catalyzed asymmetric Michael addition reaction between 2-(trifluoromethyl)oxazol-5(2H)-one as a direct C-2-position nucleophile to 4-nitro-5-styrylisoxazoles for the first time.

Origin of stereoselectivity in an isothiourea catalyzed Michael addition reaction of aryl ester with vinyl disulfone

2020 ◽  
Vol 44 (41) ◽  
pp. 17906-17911
Author(s):  
Congcong Wang ◽  
Shi-Jun Li ◽  
Min Zhang ◽  
Donghui Wei ◽  
Lina Ding
Keyword(s):  
Michael Addition ◽  
Addition Reaction ◽  
Michael Addition Reaction ◽  
First Time ◽  
Aryl Ester

The origin of stereoselectivity in an isothiourea-catalyzed addition reaction of aryl ester with vinyl disulfone was explored for the first time.

scholarly journals Concerted Catalysis by Nanocellulose and Proline in Organocatalytic Michael Additions

Molecules ◽  
2019 ◽  
Vol 24 (7) ◽  
pp. 1231 ◽  
Author(s):  
Naliharifetra Ranaivoarimanana ◽  
Kyohei Kanomata ◽  
Takuya Kitaoka
Keyword(s):  
Catalytic Activity ◽  
Organic Synthesis ◽  
Michael Addition ◽  
Cellulose Nanofibers ◽  
Next Generation ◽  
Michael Additions ◽  
Asymmetric Michael Addition ◽  
First Time

Cellulose nanofibers (CNFs) have recently attracted much attention as catalysts in various reactions. Organocatalysts have emerged as sustainable alternatives to metal-based catalysts in green organic synthesis, with concerted systems containing CNFs that are expected to provide next-generation catalysis. Herein, for the first time, we report that a representative organocatalyst comprising an unexpected combination of 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO)-oxidized CNFs and proline shows significantly enhanced catalytic activity in an asymmetric Michael addition.

Sequential Michael addition thiol–ene and radical-mediated thiol–ene reactions in one-pot produced sequence-ordered polymers

2015 ◽  
Vol 6 (9) ◽  
pp. 1527-1532 ◽  
Author(s):  
Lei Yu ◽  
Long-Hai Wang ◽  
Zong-Tao Hu ◽  
Ye-Zi You ◽  
De-Cheng Wu ◽  
...  
Keyword(s):  
Free Radical ◽  
Michael Addition ◽  
One Pot ◽  
Ene Reactions ◽  
First Time

Sequential Michael addition-based thiol–ene and free radical mediated thiol–ene reactions for preparing sequence-ordered polymers are reported for the first time.

Novel triple responsive polybenzimidazole synthesized via amine-ene Michael addition

2018 ◽  
Vol 42 (14) ◽  
pp. 11396-11403 ◽  
Author(s):  
Lilong Gao ◽  
Wenlin Wang ◽  
Bing Yu ◽  
Hailin Cong
Keyword(s):  
Drug Delivery ◽  
Michael Addition ◽  
Drug Delivery Systems ◽  
Delivery Systems ◽  
First Time

BITO polyesters were synthesized for the first time, which show pH, CD and ROS responsiveness and have great potential as drug delivery systems.

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