نتایج جستجو برای: triphenylphosphine
تعداد نتایج: 925 فیلتر نتایج به سال:
High molecular weight sugar poly(orthoesters) were synthesized through reverse anomeric effect (RAE). We demonstrated that when RAE-enabled promoters, such as 4-(dimethylamino)pyridine (DMAP), triphenylphosphine (TPP) or imidazole, were employed, efficient polymerizations were achieved, giving sugar poly(orthoesters) with molecular weights up to 18 kDa.
The application of a monolithic form of triphenylphosphine to the Ramirez gem-dibromoolefination reaction using flow chemistry techniques is reported. A variety of gem-dibromides were synthesised in high purity and excellent yield following only removal of solvent and no further off-line purification. It is also possible to perform the Appel reaction using the same monolith and the relationship...
A near-infrared chemosensor for palladium based on the Tsuji-Trost reaction was developed. It displayed specific and ratiometric fluorescent responses toward palladium with a distinct color change from green to blue in aqueous media. PEG400 was employed as the reducing agent and palladium ligand instead of water-insoluble triphenylphosphine. The chemosensor's bioimaging potential was demonstrat...
Many examples exist of biological self-assembled structures that restructure in response to external stimuli, then return to their previous state over a defined time scale, but most synthetic investigations so far have focused on systems that switch between states representing energetic minima upon stimulus application. Here we report an approach in which triphenylphosphine is used as a chemica...
An efficient synthesis of 2H-thiopyran derivatives via three-component reaction of alkyl propiolate, benzoyl isothiocyanate or its derivatives and alkyl bromides in the presence of triphenylphosphine in water at 80o C without using any catalyst in water is described. The method offers several advantages including high yields of products and an easy work-up procedure.
We reported a universal route for synthesizing porous organic ligands (POLs) via solvothermal polymerization. The POLs were obtained quantitatively, showing high surface area, large pore volume, hierarchical porosity, and superior stability. The POL bearing a triphenylphosphine supported rhodium catalyst (Rh/POL-PPh3) exhibits high activity and excellent recyclability in 1-octene hydroformylation.
Aerobic recycling: A catalytic amount of a hydrazine reagent is sufficient to promote Mitsunobu reactions in the presence of triphenylphosphine, an iron catalyst, and air. The active form of the catalyst, an azo species, can be readily generated by iron-catalyzed aerobic oxidation. MS = molecular sieves, Pc = phthalocyanine.
In the presence of triphenylphosphine, copper(II) chloride can catalyze an intermolecular ortho-acylation reaction of phenols with aryl aldehydes. The reaction proceeds smoothly with a wide range of starting materials, and furthermore, it can be used to synthesize xanthone derivatives in a single step in high yields.
A novel triphenylphosphine-mediated direct trifluoromethylthiolation of indole derivatives using trifluoromethanesulfonyl chloride as the SCF3 source was developed. Sodium iodide facilitated this transformation by generating iodine in situ which was found to accelerate this transformation. The use of a transition metal-free protocol, readily available reagents, and mild reaction conditions allo...
Abstract: Aryl halides and aryl triflates (triflate = trifluoromethanesulfonyl) are coupled with N-compounds to give the corresponding arylamines or arylhydrazines in the presence of a palladium catalyst, a suitable ligand, and a base. Catalyst systems consisting of palladium (II) and BINAP or triphenylphosphine are generally effective for the amination of a wide range of aryl halides and aryl ...
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