Synthesis of Alkenyl Sulfides Catalyzed by CuNPs/TiO2. A Theoretical-Computational Analysis (original) (raw)
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Advanced Synthesis & Catalysis, 2013
Copper oxide nanoparticles that are supported on graphene oxide as a catalytic system have been utilized for ligand-free and solvent-free C À S cross-coupling reactions with weak bases such as tri-A C H T U N G T R E N N U N G ethylamine. Symmetrical/unsymmetrical aryl sulfides have been synthesized by the coupling of different aryl halides with aromatic as well as aliphatic sulfides. Surprisingly, aryl chlorides also well reacted with different types of sulfides in the presence of dimethyl sulfoxide and cesium carbonate. Besides, this catalytic system is suitable for the synthesis of phenothiazines via cascade C À S and C À N cross-coupling of ortho-dihalides and ortho-aminobenzothiazoles. In addition, this alternative approach is extremely useful for the synthesis of a variety of symmetrical diaryl sulfides by using thiourea as a sulfur source that is devoid of the foul smell of thiols. Indeed, the calculated E-factor value of our present protocol is 2.52. Furthermore, this protocol is particularly attractive as an environmentally benign and practical method for the synthesis of different aryl sulfides. Moreover, the heterogeneous catalytic system described in this process represents not only a greener approach but retains its significant activity for up to six catalytic cycles.
ChemInform, 2014
Highly active and selective aerobic cross-dehydrogenative coupling of terminal alkynes with thiols to construct alkynyl sulfides catalyzed by Cu(I) using molecular oxygen as the oxidant has been demonstrated under mild reaction conditions. The process is applicable to a wide range of alkynes and various thiols and is compatible with a variety of functional groups on both alkyne and thiol coupling partners. † Electronic supplementary information (ESI) available: Detailed experimental procedures, and spectral data for all compounds, including scanned images of 1 H and 13 C NMR spectra. See
Journal of Nanoparticle Research, 2016
Hexagonal copper-deficient copper(I) sulfide (Cu 2-x S, x = 0.03, 0.2) nanocrystals (NCs) are synthesized from a newly prepared single-source precursor (SP), [Cu(bdpa) 2 ][CuCl 2 ], where bdpa is benzyl 3,5-dimethyl-pyrazole-1-carbodithioate. The SP is crystallized with space group Pī and possesses a distorted tetrahedron structure with a CuN 2 S 2 chromophore where the central copper is in ?1 oxidation state. Distortion in copper(I) structure and the low decomposition temperature of SP make it favorable for the low-temperature solvent-assisted selective growth of high-copper content sulfides. The nucleation and growth of Cu 2-x S (x = 0.03, 0.2) are effectively controlled by the SP and the solvent in the solvothermal decomposition process. During decomposition, fragment benzyl thiol (PhCH 2 SH) from SP effectively passivates the nucleus leading to spherical nanocrystals. Further, solvent plays an important role in the selective thermochemical transformation of Cu Icomplex to Cu 2-x S (x = 0.03, 0.2) NCs. The chelating binders (solvent) like ethylene diamine (EN) and ethylene glycol (EG) prefer to form spherical Cu 1.97 S nanoparticles (djurleite), whereas nonchelating hydrazine hydrate (HH) shows the tendency to furnish hexagonal platelets of copper-deficient Cu 1.8 S. The optical band gap values (2.25-2.50 eV) show quantum confinement effect in the structure. The synthesized NCs display excellent catalytic activity (*87 %) toward photodegradation of organic dyes like Congo Red (CR) and Methylene Blue (MB).
Tetrahedron Letters, 2011
Recyclable copper oxide nanoparticles catalyzed simple and highly efficient protocol for the synthesis of symmetrical aryl sulfides was developed by the cross-coupling of aromatic halides with inexpensive and commercially available thiourea which was used as an effective sulfur surrogate. The present cross-coupling protocol of thiourea, via cascade reaction with various substituted aryl halides, producing desired aryl sulfides, has an added advantage of avoiding foul-smelling thiols.
Nano copper oxide catalyzed synthesis of symmetrical diaryl sulfides under ligand free conditions
Potassium thiocyanate acts as an efficient sulfur surrogate in C–S cross-coupling reactions mediated by recyclable copper oxide nanoparticles under ligand free conditions. This protocol avoids foul smelling thiols, for the synthesis of a variety of symmetrical diaryl sulfides, via the cross-coupling of different aryl halides with potassium thiocyanate, affording corresponding products in moderate to excellent yields.
ChemInform Abstract: Metal Nanoparticles as Efficient Catalysts for Organic Reactions
ChemInform, 2010
Pd(0) nanoparticles have been demonstrated to be very efficient catalysts for C-C bond-forming reactions. These include coupling of vicinal-diiodoalkenes and acrylic esters and nitriles leading to the stereoselective synthesis of 2-alkene-4-yn-esters and nitriles, allylation of active methylene compounds by allyl acetate, and Hiyama cross-coupling of aryl iodides with arylsilanes. Cu(0) nanoparticles catalyze aryl-sulfur bond formation, accomplishing the synthesis of functionalized aryl sulfides and aryl-and vinyl dithiocarbamates. Cu nano particles have also been used for the chemoselective reduction of aromatic nitro compounds.
Metal nanoparticles as efficient catalysts for organic reactions
Pure and Applied …, 2009
Pd(0) nanoparticles have been demonstrated to be very efficient catalysts for C-C bond-forming reactions. These include coupling of vicinal-diiodoalkenes and acrylic esters and nitriles leading to the stereoselective synthesis of 2-alkene-4-yn-esters and nitriles, allylation of active methylene compounds by allyl acetate, and Hiyama cross-coupling of aryl iodides with arylsilanes. Cu(0) nanoparticles catalyze aryl-sulfur bond formation, accomplishing the synthesis of functionalized aryl sulfides and aryl-and vinyl dithiocarbamates. Cu nano particles have also been used for the chemoselective reduction of aromatic nitro compounds.
Some insight on the structure/activity relationship of metal nanoparticles in Cu/SiO2 catalysts
Chinese Journal of Catalysis, 2019
The activity of two Cu/SiO2 catalysts prepared by the chemisorption hydrolysis technique has been tested in the hydrogenation reaction of 3-methyl-cyclohexanone. Both catalysts were found to be very active at 60 °C and 1 atm of H2. Characterization of the materials by FT-IR of adsorbed CO and TEM put in light the presence of well formed Cu cristallites. By assuming a cuboctahedral model we could show that the hydrogenation activity is linked to high coordination sites on the metal particle. A comparison is also reported with a sample prepared by ammonia evaporation that was found to be inactive in the hydrogenation reaction under the same experimental conditions.