scholarly journals Chemoselective aza-Michael addition of indoles to 2-aroyl-1,3-diarylenones

2019 ◽  
Vol 44 (1-2) ◽  
pp. 97-103
Author(s):  
Zheng Li ◽  
Aizhen Yang ◽  
Xiaolong Ma ◽  
Zhenrong Liu

A total of 20 examples of 2-[(1 H-indol-1-yl)(aryl)methyl]-1,3-diphenylpropane-1,3-diones were efficiently synthesized by the aza-Michael addition at the N1 position of indoles with 2-aroyl-1,3-diarylenones at room temperature in the presence of potassium hydroxide. The salient features of this protocol are no transition-metal catalysts, mild conditions, high chemoselectivity, high atom economy, high yields, and a simple work-up procedure.

2018 ◽  
Vol 42 (4) ◽  
pp. 210-214
Author(s):  
Bo Chen ◽  
Jiaheng Lei ◽  
Junling Zhao

A mild and efficient catalyst-free method for the rapid synthesis at room temperature of 3-thiomethylated oxindole derivatives has been achieved via the Michael addition of aryl thiols to ring and 1-substituted 3-(2,2,2-trifluoroethylidene)oxindoles in dichloromethane. The method was applicable to a wide range of thiols and variously substituted 3-(2,2,2-trifluoroethylidene)oxindoles under mild conditions as demonstrated by the synthesis in high yields with good diastereoselectivities of 30 3-thiomethylated oxindoles bearing a trifluoromethyl group.


Synlett ◽  
2019 ◽  
Vol 31 (02) ◽  
pp. 194-198
Author(s):  
Aizhen Yang ◽  
Zheng Li

An efficient method for the direct construction of C(sp2)–C(sp2) bonds by aerobic oxidative cross-coupling of indoles with arylidenemalononitriles is described. Various [aryl(1H-indol-3-yl)methylene]malononitriles were efficiently synthesized by using air as an oxidant under mild conditions. The salient features for this protocol are no transition-metal catalysts, no organometallic reagents, high atom economy, high yield, mild conditions, and simple workup procedures.


RSC Advances ◽  
2015 ◽  
Vol 5 (35) ◽  
pp. 27439-27442 ◽  
Author(s):  
Jian Gao ◽  
Xiaojun Pan ◽  
Juan Liu ◽  
Junyi Lai ◽  
Liming Chang ◽  
...  

A facile and highly efficient method for the synthesis of sulfonate esters mediated by iodine at room temperature has been developed, without transition metal catalysts and oxidants.


Author(s):  
Suman Suman ◽  
Rajvir Singh ◽  
Susheel Gulati ◽  
Suprita Suprita

New and facile one-pot approach for the synthesis of substituted benzimidazoles from the reaction of substituted benzaldehyde and o-phenylenediamine room temperature using Rice Husk Ash: CaCl2 (RHA:CaCl2) as a green catalyst was presented in the paper. After the completion of the reaction, the reaction mixture was poured into ice-coldwater with stirring, and the precipitated product was filtered using the filter pump. The crude product was then recrystallized from ethanol to give analytically pure samples in good to excellent yield. The purity of compounds were characterized by melting point and thin-layer chromatography. The synthesized compounds were characterized by using 1HNMR and FTIR spectral techniques.Metal-free, short reaction time, high yields, mild reaction condition, simple work-up, high atom economy, cost-effectiveness, and no need for column purification are some beauties of this methodology.


2017 ◽  
Vol 23 (4) ◽  
Author(s):  
Zheng Li ◽  
Tianpeng Li ◽  
Rugang Fu ◽  
Jingya Yang

AbstractThe regioselective 1,4-conjugate aza-Michael addition of dienones with benzotriazole catalyzed by potassium acetate is described. A series of 3-(benzotriazol-1-yl)-1,5-diarylpent-4-en-1-ones were efficiently synthesized under mild conditions. This protocol has advantages of transition-metal free catalyst, high yield and high regioselectivity.


2019 ◽  
Vol 10 (2) ◽  
pp. 166-170 ◽  
Author(s):  
Fatma Ahmed Abo Elsoud ◽  
Mohamed Abd-Elmonem ◽  
Mohamed Abo Elsebaa ◽  
Kamal Usef Sadek

Efficient synthesis of non-annulated 2-amino-4H-pyrans and 2-amino-8-oxo-4,8-dihydropyrano[3,2-b]pyran derivatives, which are biologically relevant heterocycles is achieved, utilizing a domino three-component reaction of ethyl acetoacetate or kojic acid with aromatic aldehydes and malononitrile catalyzed by Zn(L-proline)2 as reusable organometallic catalyst. The process exhibits high atom economy, short reaction time, simple work up, high yields and environmentally friendly nature. Excellent yields of the targeted molecules have been obtained.


2018 ◽  
Vol 24 (1) ◽  
pp. 23-26
Author(s):  
Zheng Li ◽  
Wenli Song ◽  
Jiaojiao He ◽  
Yan Du ◽  
Jingya Yang

Abstract An efficient method for the synthesis of the title compounds by reactions of divinyl ketones with thiourea is described. This protocol has the advantages of high yields, mild reaction conditions and simple work-up procedure.


2019 ◽  
Vol 15 ◽  
pp. 874-880
Author(s):  
Razieh Navari ◽  
Saeed Balalaie ◽  
Saber Mehrparvar ◽  
Fatemeh Darvish ◽  
Frank Rominger ◽  
...  

An efficient approach for the synthesis of pyrazolopyridines containing the aminochromane motif through a base-catalyzed cyclization reaction is reported. The synthesis was carried out through a three-component reaction of (arylhydrazono)methyl-4H-chromen-4-one, malononitrile, primary amines in the presence of Et3N at room temperature. However, carrying out the reaction under the same conditions without base led to a fused chromanyl-cyanopyridine. High selectivity, high atom economy, and good to high yields in addition to mild reaction conditions are the advantages of this approach.


RSC Advances ◽  
2014 ◽  
Vol 4 (46) ◽  
pp. 24300-24303 ◽  
Author(s):  
Gaoqing Yuan ◽  
Zechen Zhu ◽  
Xiaofang Gao ◽  
Huanfeng Jiang

An efficient electrochemical route has been developed to synthesize polysubstituted oxazoles, without the use of hazardous oxidants and transition metal catalysts.


RSC Advances ◽  
2014 ◽  
Vol 4 (65) ◽  
pp. 34548-34551 ◽  
Author(s):  
Indresh Kumar ◽  
Nisar A. Mir ◽  
Panduga Ramaraju ◽  
Deepika Singh ◽  
Vivek K. Gupta ◽  
...  

An organocatalytic formal [3 + 2] cycloaddition have been developed between 1,4-ketoaldehydes and imines to synthesize densely substituted 3-formylpyrroles in high yields (up to 70%) under mild conditions at room temperature.


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