Solvent effects in heterogeneous catalysis : Application to the synthesis of fine chemicals

Solvent effects in the liquid phase hydrodeoxygenation of methyl propionate over a Pd(1 1 1) catalyst model

“…rates and product distributions with the polarity or dielectric constant and activity coefficients. [7][8][9][10] It has been observed that a polar solvent often enhances the adsorption of the non-polar reactant, while a non-polar solvent enhances the adsorption of a polar reactant. [10][11][12][13] For example in the competitive hydrogenation of acetone and cyclohexene, polar solvents enhanced the reaction rate of the conversion of cyclohexene to cyclohexane while it reduced the adsorption of acetone.…”

“…To investigate the effects of the presence of liquid water and 1,4-dioxane on the adsorption strength of the intermediates involved in the HDO of methyl propionate, we computed the adsorption free energy in the absence and presence of solvents (8) (9) and calculated the effects of the solvents on the free energy of adsorption of the surface intermediates as (10) where, and are the free energy of adsorption of a gas molecule of intermediate A in the presence and absence of solvent, and are the free energy of adsorbed A in the presence and absence of solvent, and and are the free energy of the free active site/surface model of the catalyst in the presence and absence of solvent. We note that while many surface intermediates are unstable if separated from the Pd surface, the procedure described above permits understanding the effects of a solvent on the free energy of an adsorbed surface intermediate.…”

RhCl(TPPTS)3 supported on iota‐carrageenan as recyclable catalysts for Suzuki cross‐coupling

“…Most organic transformations are performed in the liquid phase, in which solvents are often used to bring together and solubilize reactants, to facilitate heat and mass transfer, and to assist in reaction workup. Solvent choice is therefore crucial, as it influences catalyst activity and determines the ease with which the product can be separated from the solution and the catalyst can be recycled . As it involves polar and apolar organic substrates, an inorganic base and a metal catalyst, Suzuki cross‐coupling reactions are traditionally performed in polar solvents, such as dimethylformamide (DMF), dimethyl sulfoxide (DMSO) or various alcohols.…”

Microwave assisted synthesis of 1H-tetrazole-based flavonoid derivatives and their antimicrobial activity

“…Aurones possess antifeedant, 25 anti-inflammatory, 26 anticancer, 27 antileishmanial, 28 antibacterial 29 and antioxidant activity, 19 and also show inhibitory activity against a variety of enzymes and proteins. 30,31 Microwave irradiation has become an important technique in organic synthesis and has attracted the attention of researchers because of its various advantages, such as shorter reaction times, higher yields, consumption of small amount of energy, 32,33 experimental simplicity and selectivity over the conventional heating technique.…”