Isomerization and hydrolysis reactions of important disaccharides over inorganic heterogeneous catalysts

A Monte Carlo analysis of acid hydrolysis of glycosidic bonds in polysaccharides

“…Hydrolysis by enzymes is also feasible, but for cellulose there are obstacles due to the expenses associated with the growth of the cellulase-producing organism, the narrow operating ranges under which they can be utilized, and the occurrence of cellobiose inhibition (Shukla et al, 1985). Additionally, a cellulase enzyme is about five times bigger than the acid catalyst, thus penetrating more slowly in the macroscopic structure of cellulose (Ladisch, 1989).…”

Glucose isomerisation into fructose over magnesium-impregnated NaY zeolite catalysts

“…In the case of magnesium oxide, high glucose conversions (62-67%) are reached after 1h of reaction at 100°C, which were even higher than the equilibrium glucose conversion at 100°C (57% [21]), but with low fructose selectivities (38-44%) [35]. On the other hand, hydrotalcites, alkaline-exchanged zeolites and metallosilicates have demonstrated not only reasonable activity but also high selectivity to fructose (60 to 86%) under similar operating conditions [28][29][30][31][32]36].…”

“…Heterogeneous catalysts tested for the isomerisation of glucose into fructose are mostly basic solid materials such as hydrotalcites [28][29][30][31], alkaline-exchanged zeolites [28,30,32], anionexchanged resins [33], mesoporous ordered molecular sieves of the M41S family [34], magnesium oxide [35] and metallosilicate solid bases [36]. Temperatures below 120°C are usually used in order to avoid secondary transformations, and water is commonly selected as solvent.…”

“…Na-exchanged X, Y and A zeolites have been the most investigated basic materials [28,30,32]. In these studies, A and X zeolites present better performances for the sugars transformation than the Y zeolite, which appears to be mostly dependent on the Si/Al ratio, as the lower this parameter the greater the degree of ion-exchange with Na.…”

Reactions of N‐, S‐ and O‐Nucleophiles with 3,4,6‐Tri‐O‐benzyl‐D‐glucal Mediated by Triphenylphosphane Hydrobromide versus Those with HY Zeolite

“…[42] Acid zeolites, which are widely used as catalysts, are microporous crystalline materials that allow environmentally acceptable procedures for the synthesis of fine chemicals. [43][44][45][46] Among them, the HY zeolites have been employed in carbohydrate chemistry to promote isomerisation and hydrolysis of disaccharides [47,48] and hydrolysis of methyl glucosides [49] and sucrose. [50] The synthesis of butyl glucopyranosides [51] and glucosylation of alcohols with 1,2-anhydro-α--glucopyranose derivatives, catalysed by HY zeolites, have also been reported.…”