نتایج جستجو برای: heterocycles

تعداد نتایج: 2986  

2017
Mohammad Asif

Heterocycles have vital interest in the pharmaceuticals and agrochemicals. Synthetic chemistry provides wealth of heterocyclic systems. More than 90% of drugs contain heterocycles ring and the interface between chemistry and biology. Scientific insight, discovery and applications are taking place by heterocyclic compounds. This review article covers theactive heterocycles that have shown consid...

2016
Franziska Hemmerling Frank Hahn

This review highlights the biosynthesis of heterocycles in polyketide natural products with a focus on oxygen and nitrogen-containing heterocycles with ring sizes between 3 and 6 atoms. Heterocycles are abundant structural elements of natural products from all classes and they often contribute significantly to their biological activity. Progress in recent years has led to a much better understa...

Journal: :The Journal of organic chemistry 2013
Óscar Pablo David Guijarro Miguel Yus

Highly optically enriched, protected, nitrogenated heterocycles with different ring sizes have been synthesized by a very efficient methodology consisting of the asymmetric transfer hydrogenation of N-(tert-butylsulfinyl)haloimines followed by treatment with a base to promote an intramolecular nucleophilic substitution process. N-protected aziridines, pyrrolidines, piperidines, and azepanes bea...

2013
Rajiv Dua Suman Shrivastava S. K. Sonwane S. K. Srivastava

Abstract: Heterocyclic chemistry offers an example for the lack of distinct demarcations; in fact, it pervades the plurality of the other chemical disciplines. Heterocycles are inextricably woven into the life processes. The vital interest of the pharmaceutical and agrochemical industries in heterocycles is often connected with their natural occurrence. Synthetic chemistry provides cornucopia o...

2013
Xiang-Guo Hu Luke Hunter

The stereoselective incorporation of fluorine atoms into N-heterocycles can lead to dramatic changes in the molecules' physical and chemical properties. These changes can be rationally exploited for the benefit of diverse fields such as medicinal chemistry and organocatalysis. This brief review will examine some of the effects that fluorine substitution can have in N-heterocycles, including cha...

Journal: :Molecules 2015
Hideto Miyabe

Most of the synthetic approaches to the benzo-fused heterocycles containing an oxygen atom have involved the use of phenol derivatives as a starting material. This review highlights the new synthetic approaches involving the aromatic C-O bond-forming process using arynes. The insertion of arynes into the C=O bond gives the unstable intermediates, [2 + 2] cycloaddition-type adducts, which can be...

Journal: :Chemical reviews 2006
Gilson Zeni Richard C Larock

Palladium-catalyzed processes have proven to be a powerful and useful tool for the synthesis of heterocycles. Palladium has found such wide utility because it affects an extraordinary number of very different reactions, including many carbon-carbon bond-forming reactions, under relatively mild reaction conditions. Furthermore, palladium can usually be used in only catalytic amounts and tolerate...

Journal: :Chemistry 2009
Praew Thansandote Mark Lautens

Nitrogen heterocycles are abundant in natural products and pharmaceuticals. An emerging interest among synthetic chemists is to use C-H functionalization to construct the nitrogen-containing core of these heterocycles. The following article will provide a brief overview of this concept with respect to the type of C-H bond functionalized.

Journal: :Organic & biomolecular chemistry 2011
Raouf Medimagh Sylvain Marque Damien Prim Saber Chatti

β-Alkylation of amino-furan and -thiophene heterocycles is described through metal-, acid- and base-free carbon-carbon bond formation. The ability of both heterocycles to undergo selective β-alkylation is compared by mean of experimental and theoretical data. The presence of chiral amine substituents induced the diastereoselective generation of the newly formed additional stereocenter.

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید