Aryl halides

Ebook "Transition metal catalyzed carbonylative synthesis of heterocycles" provides readers with contents including: ruthenium-catalyzed carbonylative synthesis of heterocycles; rhodium-catalyzed carbonylative synthesis of heterocycles; palladium-catalyzed carbonylative synthesis of six-membered heterocycles from aryl halides; pd-catalyzed carbonylative synthesis of other-membered heterocycles from aryl halides;...

176p tracanhphuonghoa1007 22-04-2024 4 2   Download

Ebook "Amination and formation of sp2 C–N bonds (Topics in Organometallic chemistry, Volume 46)" highlights in the first chapter, written by Lemen and Wolfe, the discovery and the development of original palladium-based catalysts for C(sp2 )-N bond formation via the coupling of nitrogen nucleophiles and aryl/alkenyl halides and pseudohalides. The authors also report various applications of these transformations to the synthesis of useful compounds, including biologically active molecules and materials.

214p coduathanh1122 27-03-2024 7 1   Download

Two series of 6-arylazothiazol[2,3-c][1,2,4]triazoles were prepared via oxidative cyclization of the respective aldehyde N-(5-arylazo-4-methylthiazol-2-yl)-hydrazones. The structures of the latter hydrazone precursors and the azo compounds were confirmed by spectral and elemental analyses. The solvatochromism of the title azo dyes is evaluated by means of the Kamlet–Taft equation and discussed.

9p langthannam 29-12-2021 6 0   Download

The new complexes (1–3) were characterized by elemental analysis and spectroscopic methods and the molecular structure of 1a was determined by X-ray diffraction studies. These complexes were applied in the Suzuki–Miyaura cross-coupling reaction of phenylboronic acid with aryl halides in neat water. The activities of catalysts were monitored by gas chromatography–flame ionization detector and nuclear magnetic resonance.

10p langthannam 29-12-2021 12 0   Download

Very small concentrations of a dimeric C,N-palladacycle were used as an efficient homogeneous catalyst for Sonogashira cross-coupling reactions between various aryl halides and phenylacetylene. The catalytic reactions were performed without the need for copper in DMF/H2O. This catalytic system shows excellent yields for aryl iodides and bromides and even in the case of aryl chlorides.

9p langthannam 29-12-2021 5 0   Download

Addressed herein is the catalysis of monodisperse palladium nanoparticles (NPs) supported on chemically derived graphene (CDG) for the Suzuki–Miyaura cross-coupling of phenylboronic acid and various aryl halides. Monodisperse Pd NPs were synthesized by the solution phase reduction of palladium(II) acetylacetonate with morpholine borane complex in oleylamine and deposited on CDG via the liquid phase self-assembly method. Colloidal Pd NPs and CDG-Pd catalyst were characterized by TEM, XRD, SEM, and ICP-MS analyses.

10p langthannam 29-12-2021 11 0   Download

The incorporation of N -coordinated benzimidazole complexes of palladium gave high catalytic activity in the Suzuki–Miyaura coupling of aryl halides substrates. After determining the best active catalyst as 5A1, bearing the mesityl substituent on the benzimidazole ring with the Pd(II) ion, optimization studies were carried out via changing the substrate, base, time, atmosphere, and the effect of water. The DMF:H2O (4/1) and Cs2CO3 as base were found to be critical for the efficiency of the reaction yield (100%).

11p langthannam 29-12-2021 12 0   Download

In this work, new tunable aryl alkyl pyrazolium tetrafluoroborate ionic liquids/salts, 2-ethyl-1-(p-X-phenyl)-3,5- dimethylpyrazolium tetrafluoroborate [X: -Br (4a), -OCH3 (4b), -NO2 (4c)] and 2-butyl-1-(p-X-phenyl)-3,5-dimethylpyrazolium tetrafluoroborate [X: -Br (5a), -OCH3 (5b), -NO2 (5c)], were synthesized by following halide-free synthetic route. Their chemical structures were identified through NMR (1 H, 13C, 19F), IR, elemental analysis, and HRMS data. The synthesized 4a-4c and 5a-5c salts were used for the removal studies of methyl orange dye from aqueous solutions.

38p langthannam 29-12-2021 10 1   Download

The therapeutic applications of 1,2,4-triazoles motivated us to synthesize some new derivatives. Two series of S -substituted derivatives (8a–8j, 12a–12i) of 5-{1-[(4-chlorophenyl)sulfonyl]-3-piperidinyl}-4-phenyl-4H -1,2,4-triazol3-thiol (6) have been synthesized and evaluated for their biological potential.

20p tudichquannguyet 29-11-2021 9 1   Download

Nano-NiO catalyzed acylation of mixed (methyl)(aryl)zincs with aromatic acyl halides in THF at room temperature provides a new facile route for aryl–aroyl coupling. Among NiCl2.L2 and NiCl2.L (L = monodentate and bidentate phosphine ligand) catalysts, the lower catalyst loading of NiCl2 (dppf) may seem attractive; however, nano-NiO, being the lowest cost catalyst, is more favorable for aroylation of (methyl)(aryl)zincs. This procedure also provides a supplement to Cu and Pd catalyzed acylation of diorganozincs.

9p tudichquannguyet 29-11-2021 9 1   Download

The regioselective demethoxylation and dehalogenation of dihalogenated dibenzocyclooctadiene lignans derivatives were realized in a one-step reaction with excellent yields in the sodium and t-butanol reaction system.

9p vijiraiya2711 27-05-2020 10 1   Download

Suzuki C–C cross-coupling of aryl halides with aryl boronic acids using new phosphene-free palladium complexes as precatalysts was investigated. A pyridine-based Pd(II)-complex was used in open air under thermal as well as micro‑ wave irradiation conditions using water as an eco-friendly green solvent.

9p vijiraiya2711 27-05-2020 10 1   Download

A facile and efficient palladium-catalyzed borylation of aryl (pseudo)halides at room temperature has been developed. Arylboronic esters were expeditiously assembled in good yields and with a broad substrate scope and good functional group compatibility.

8p vijiraiya2711 27-05-2020 7 1   Download

In this work, the Fe3O4@SiO2@AMBI/Cu nanocatalyst was synthesized and used as a well-organized magnetic nanocatalyst for the click reaction. This nanocatalyst has effectively catalyzed the cyclization of terminal alkynes and sodium azide with aryl iodide/benzyl halide for the formation of 1,4-disubstituted 1,2,3-triazoles under mild reaction conditions with good to high yields in low reaction time.

10p tocectocec 25-05-2020 8 1   Download

This review summarizes results from the literature concerning synthesis and azo-hydrazone tautomerism of arylazo- and hetarylazo-derivatives of various bi- and tri-heterocycles reported by us and other research groups from 1981 to mid 2009.

36p kethamoi1 20-11-2019 11 2   Download

Starting from N-aryl 2-aroylhydrazono-propanehydrazonoyl chlorides, a series of new functionalized 1,3,4-thiadiazoles were prepared. The structures of the compounds prepared were confirmed by both elemental and spectral analyses as well as by alternate synthesis. The mechanisms of the studied reactions are outlined. The antimicrobial activities of the compounds prepared were screened and the results showed that most of such compounds exhibit considerable activities.

9p trinhthamhodang1 16-11-2019 11 0   Download

We have developed a general method for reverse aromatic Finkelstein reactions. Good reaction yields were obtained when aryl iodides or aryl bromides were treated with copper halide salts as promoters in a 1-butyl-3-methylimidazolium bromide ([BMIM]Br) ionic liquid (IL) solvent at 140 C for 8 h. Preliminary investigation supported that the copper salts were also the halide sources in halogen exchange reactions. The optimized conditions are applicable to a variety of substrates and have excellent functional group tolerance.

5p trinhthamhodang1 14-11-2019 11 0   Download

The three ionic liquids were demonstrated to be an efficient and recyclable solvent for the Heck cross-coupling reaction between several aryl halides and styrene under microwave irradiation to form trans-stilbenes as the principal products.

8p giesumanh 13-11-2018 20 0   Download

Using the ionic liquid as the reaction solvent in conjunction with microwave irradiation, the reaction rate was dramatically enhanced, with 99% conversion being achieved within 2 minutes, while less than 5% conversion was observed after 8 hours for the reaction under conventional heating condition. Furthermore, the ionic liquid could be reused without significant degradation in activity.

7p giesumanh 13-11-2018 23 0   Download

Aryl halide chỉ phản ứng nếu nhân thơm chứa nhóm thế hút điện tử mạnh như -NO2 ở vị trí o-, p- hoặc ở điều kiện khắc nghiệt. Tham khảo bài thuyết trình 'hóa học hữu cơ - chương 13', tài liệu phổ thông, hóa học phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả

36p suatuoi_thomngon 30-07-2011 227 43   Download