49594-84-5

Upstream product

• 536-74-3 phenylacetylene 
• 65-85-0 benzoic acid 
• 161776-41-6 1-hydroxy-2-phenyl-2-(2',2',6',6'-tetramethyl-1'-piperidinyloxy)ethane 
• 81913-53-3 1-(2-benzoyloxy-1-phenylethoxy)-2,2,6,6-tetramethylpiperidine 
• 41252-83-9 2-bromo-2-phenylethanol 
• 100-42-5 styrene 
• 201852-49-5 potassium (E)-trifluoro(styryl)borate 
• 614-47-1 1,3-diphenyl-propen-3-one 
• 98-86-2 acetophenone 
• 769-78-8 vinyl benzoate 
• 135654-49-8 diphenyl(2,2,2-trifluoroethyl)sulfonium trifluoromethanesulfonate 

Relevant academic research and scientific papers

N-heterocyclic carbene carboxylate bidentate ligand, bidentate ruthenium complex, preparation method and application of N-heterocyclic carbene carboxylate bidentate ligand and bidentate ruthenium complex in catalyzing carboxylic acid-alkyne addition

The invention discloses an N-heterocyclic carbene carboxylate bidentate ligand, a bidentate ruthenium complex, a preparation method and application of the N-heterocyclic carbene carboxylate bidentateligand and the bidentate ruthenium complex in catalyzing

Carboxylic acid addition to terminal alkynes utilizing ammonium tagged Hoveyda-Grubbs catalyst supported on magnetically separable core/shell silica: A highly reusable and air compatible catalytic system

In this study, the performance of ammonium tagged Hoveyda-Grubbs catalyst supported on magnetically separable core/shell silica gel was tested on carboxylic acid addition reactions to terminal alkynes using a variety of carboxylic acid derivatives under air atmosphere. The catalytic system was found to be compatible with air atmosphere and can tolerate even non-degassed solvents. The reaction parameters such as temperature, substrate/catalyst ratio and the effect of carboxylic acid on the selectivity and yield of the reaction were investigated in details. The reaction of arylacetylenes with acetic acid yielded the corresponding E-isomer with conversion values up to 99% with a catalytic loading of 1% Ru. The reusability of the catalyst was tested using acetic acid/benzoic acid and phenylacetylene in toluene at 85 °C under air atmosphere. The catalyst was found to be highly reusable and maintained its activity up to 11th run, reaching a conversion value of 83% with minimum ruthenium leaching.

The Photodynamic Covalent Bond: Sensitized Alkoxyamines as a Tool to Shift Reaction Networks Out-of-Equilibrium Using Light Energy

We implement sensitized alkoxyamines as "photodynamic covalent bonds" - bonds that, while being stable in the dark at ambient temperatures, upon photoexcitation efficiently dissociate and recombine to the bound state in a fast thermal reaction. This type of bond allows for the photochemically induced exchange of molecular building blocks and resulting constitutional variation within dynamic reaction networks. To this end, alkoxyamines are coupled to a xanthone unit as triplet sensitizer enabling their reversible photodissociation into two radical species. By studying the photochemical properties of three generations of sensitized alkoxyamines it became clear that the nature and efficiency of triplet energy transfer from the sensitizer to the alkoxyamine bond as well as the reversibility of photodissociation crucially depends on the structure of the nitroxide terminus. By employing the thus designed photodynamic covalent bonding motif, we demonstrate how to use light energy to shift a dynamic covalent reaction network away from its thermodynamic minimum into a photostationary state. The network could be repeatedly switched between its minimum and kinetically trapped out-of-equilibrium state by thermal scrambling and selective photoactivation of sensitized alkoxyamines, respectively.

Regioselective Formation of Enol Esters from the Ruthenium-Catalyzed Markovnikov Addition of Carboxylic Acids to Alkynes

The ruthenium complexes [Ru(CO)2(P(p-C6H4-X)3)2(O2CPh)2] (1a, X = CF3; 1b, X = Cl; 1c, X = H; 1d, X = Me; 1e, X = OMe) were successfully applied in the regioselective Markovnikov addition of carboxylic acids to terminal alkynes, yielding valuable enol esters. Catalyst screening revealed a significant influence of phosphine's electronic nature on activity and selectivity. The highest activity was achieved with catalyst 1a, featuring the most electron-withdrawing phosphine ligand. Selectivity and activity could be further improved by the addition of catalytic amounts of AgOTf. Moreover, excellent selectivities with up to 99% of the Markovnikov product were achieved. The electronic influence of the substrates on the reaction rate was quantified by Hammett plots. By the use of electron-rich alkynes or highly acidic carboxylic acids, the reaction rate could be increased. Hence, the addition of highly acidic pentafluorobenzoic acid to electron-rich 4-methoxyphenylacetylene can even be carried out quantitatively at 25°C within 4 h. Furthermore, a broad range of simple as well as electronically or sterically challenging substrates could be isolated in good to excellent yields with high regioselectivity and under mild reaction conditions (25-70°C). The best reported activities and selectivities were obtained for the conversion of aromatic alkynes.

Palladium-catalyzed Mizoroki-Heck-type reactions of [Ph2SRfn][OTf] with alkenes at room temperature

The first Pd-catalyzed Mizoroki-Heck-type reaction of [Ph2SRfn][OTf] with alkenes is described. The reaction of [Ph2SRfn][OTf] (Rfn = CF3, CH2CF3) with alkenes in the presence of 10 mol% Pd[P(t-Bu)3]2 and TsOH at room temperature provided the corresponding phenylation products in good to high yields. The bases that benefit the traditional Mizoroki-Heck reactions severely inhibited the transformation with [Ph2SRfn][OTf], whereas acids significantly improved the reaction. This protocol supplies a new class of cross-coupling partners for Mizoroki-Heck-type reactions and gains important insights into the reactivity of phenylsulfonium salts either with or without fluorine-containing alkyl groups as the promising phenylation reagents in organic synthesis.

Organoselenium-catalyzed baeyer-villiger oxidation of α,β-unsaturated ketones by hydrogen peroxide to access vinyl esters

By carefully screening the organoselenium pre-catalysts and optimizing the reaction conditions, simple dibenzyl diselenide was found to be the best pre-catalyst for Baeyer-Villiger oxidation of (E)-α,β-unsaturated ketones with the green oxidant hydrogen peroxide at room temperature. The organoselenium catalyst used in this reaction could be recycled and reused several times. This new method was suitable not only for methyl unsaturated ketones, but also for alkyl and aryl unsaturated ketones. Therefore, it provided a direct, mild, practical, highly functional group-tolerant process for the chemoselective preparation of the versatile (E)-vinyl esters from the readily available (E)-α,β-unsaturated ketones. A possible mechanism was also proposed to rationalize the activity of the organoselenium catalyst in the presence of hydrogen peroxide in this Baeyer-Villiger oxidation reaction.

A dinuclear ruthenium catalyst with a confined cavity: Selectivity in the addition of aliphatic carboxylic acids to phenylacetylene

A dinuclear ruthenium catalyst with a rigid anthracene spacer shows excellent regio- and stereo-selectivity in the atom-economic addition of aliphatic carboxylic acids to phenylacetylene, producing exclusively anti-Markovnikov enol-esters with high E/Z ratios of the isomers.

Copper-catalyzed nondecarboxylative cross coupling of alkenyltrifluoroborate salts with carboxylic acids or carboxylates: Synthesis of enol esters

A mild copper-catalyzed Chan-Lam-Evans type cross-coupling reaction for the regioselective and stereospecific preparation of (E)- or (Z)-enol esters is described. The method couples carboxylate salts or carboxylic acids with potassium alkenyltrifluoroborate salts in the presence of catalytic CuBr and DMAP with 4 A molecular sieves under O2 at 60 C. Overall, this method demonstrates carboxylic acids as suitable reaction partners for nondecarboxylative copper-catalyzed cross-couplings to form C-O bonds in an Ullmann-like reaction.

Pd-catalysed direct dehydrogenative carboxylation of alkenes: Facile synthesis of vinyl esters

A novel Pd-catalysed oxidative coupling reaction methodology using readily available carboxylic acids and alkenes for the preparation of vinyl esters has been developed. A broad range of vinyl esters were successfully synthesised. The reactions have demonstrated good efficiency as well as excellent chemo- and regio-selectivity.

Steric control at the wingtip of a bis-N-heterocyclic carbene ligand: Coordination behavior and catalytic responses of its ruthenium compounds

Changing the N-substituents of a methylene-linked bis-NHC ligand from n-butyl to bulky mesityl shifts ligand coordination from normal/normal to normal/abnormal mode. The mesityl wingtip groups afford [RuII( MesNHC(CH2)NHC