نتایج جستجو برای: alkenes

تعداد نتایج: 5720  

2015
Mohammad Abbasi Reza Khalifeh

An efficient and odourless procedure for a one-pot synthesis of thioesters by the reaction of benzoic anhydrides, thiourea and various organic halides (primary, allylic, and benzylic) or structurally diverse, electron-deficient alkenes (ketones, esters, and nitriles) in the presence of Et3N has been developed. In this method, thiobenzoic acids were in situ generated from the reaction of thioure...

2017
Kun Shen Qiu Wang

A copper-catalyzed aminoalkynylation of alkenes is achieved with ethynylbenziodoxolone (EBX) reagents under mild conditions with only 1 mol% copper catalyst. This transformation allows for rapid construction of diverse important azahetereocycles and installation of valuable alkyne groups in one step. The developed method features remarkable substrate scope for both terminal and internal alkenes...

2003
Wolfgang A. Herrmann Roland M. Kratzer Holger B. Friedrich Richard W. Fischer David C. Apperley Janos Mink

Polymer-supported oxidic osmium catalysts based on cross-linked poly(4-vinyl pyridine) were synthesized by various routes and characterized by a number of physical techniques (Raman, IR, XPS, “C and 15N solid-state NMR spectroscopy). Model compounds of type Os,O,L, (L = pyridine, 4-iso-propyl pyridine, and 4-tert-butyl pyridine) were obtained under the conditions of the catalyst synthesis. The ...

Journal: :Bioorganic & medicinal chemistry letters 2016
Qin-Ge Ma Kun Xu Zhi-Pei Sang Rong-Rui Wei Wen-Min Liu Ya-Lun Su Jian-Bo Yang Ai-Guo Wang Teng-Fei Ji Lu-Jun Li

Four new alkenes (1-4), and six known alkenes (5-12) were isolated from Murraya koenigii (L.) Spreng. Their structures were elucidated on the basis of spectroscopic analyses and references. Compounds (1-12) were evaluated for antioxidative activities. Among them, compounds 1, 2, 4, and 7 exhibited significant antioxidative activities using 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay with IC50=21...

2014
Steven Bloom James Levi Knippel Maxwell Gargiulo Holl Ross Barber Thomas Lectka

A one step, regioselective allylic fluorination of alkenes is reported in which electrophilic and nucleophilic sources of fluorine act synergistically to afford rearranged allylic fluorides over alternative vicinal dihalides. The reaction occurs under exceptionally mild conditions and without need for prefunctionalization or transition metal catalysts. The fluorination of cyclic alkenes and mon...

Journal: :Chemical Society reviews 2003
Frauke Pohlki Sven Doye

The direct addition of ammonia or primary and secondary amines to non-activated alkenes and alkynes is potentially the most efficient approach towards the synthesis of higher substituted nitrogen-containing products. It represents the most atom economic process for the formation of amines, enamines and imines, which are important bulk and fine chemicals or building blocks in organic synthesis. ...

2017
Yan-Yun Liu Xu-Heng Yang Ren-Jie Song Shenglian Luo Jin-Heng Li

Difunctionalization of alkenes has become a powerful tool for quickly increasing molecular complexity in synthesis. Despite significant progress in the area of alkene difunctionalization involving the incorporation of a nitrogen atom across the C-C double bonds, approaches for the direct 1,2-carboamination of alkenes to produce linear N-containing molecules are scarce and remain a formidable ch...

Journal: :Photochemical & photobiological sciences : Official journal of the European Photochemistry Association and the European Society for Photobiology 2011
Margareta Horvat Kata Mlinarić-Majerski Axel G Griesbeck Nikola Basarić

Direct and sensitized excitation of 3-(N-phthalimido)adamantane-1-carboxylic acid (1) leads to the population of the triplet state that, in the presence of a base, decarboxylates, giving N-(1-adamantyl)phthalimide (2) cleanly and efficiently (Φ = 0.11). The radical initially formed by decarboxylation adds regiospecifically to electron deficient alkenes, whereas radical addition was not observed...

Journal: :Chemical communications 2012
Jian Zhang Teck-Peng Loh

Ruthenium- and rhodium-catalyzed direct oxidative cross-coupling reactions of acrylamides with alkenes were developed. These methods provide an efficient route for the synthesis of (Z,E)-dienamides in excellent yields with good stereoselectivity. The catalytic systems allowed oxidative olefination of a wide range of alkenes bearing different functional groups, such as CO(2)R, COMe, SO(2)Ph, ary...

Journal: :The Journal of organic chemistry 2017
Leilei Wang Huilan Yue Daoshan Yang Huanhuan Cui Minghui Zhu Jinming Wang Wei Wei Hua Wang

A facile I2O5-mediated direct oxidative coupling of aromatic alkenes with thiols toward vinyl sulfones has been developed under metal-free conditions. This methodology provides a convenient and efficient approach to various (E)-vinyl sulfones from readily available starting materials with excellent regioselectivity. The present oxidative coupling reaction, not only expands the scope of function...

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