Synergism of Microwaves and Immobilized Enzyme Catalysis in Synthesis of Adipic Acid Esters in Nonaqueous Media

Abstract

Low-energy microwave irradiation leads to enhancement by a factor of up to 2.63 in comparison with conventional heating in immobilized lipase-catalyzed esterification of adipic acid with various alcohols and this effect is due to the greater frequency of collision, without any change in activation energy of the two modes of heating.

Microwave-assisted solvent-free lipase catalyzed transesterification of β-ketoesters

“…When reactions were conducted in that way, yields in the range of 80% were only achieved after 48 h (49). Consequently, not only the enzyme was active under the reaction conditions, but an enhancement in the activity was achieved under microwave irradiation, consistent with literature reports (21,25,33). Remarkably, significant higher yields were observed in solvent-free conditions, compared to literature data (21).…”

“…Likewise, Yadav and colleagues highlighted the synergism between lipase activity and microwave irradiation in CAL B-catalyzed transesterifications (21,25,33). Moderate-to-good conversions at short reaction times compared to conventionally heated reactions were reported.…”

Insight into microwave irradiation and enzyme catalysis in enantioselective resolution of RS‐( ± )‐methyl mandelate

“…Lipase-catalyzed reactions are rather sluggish in nature; synergism with microwaves can be expected to enhance the rates of reactions. 12,14,17 It has been reported that in a number of chemically catalyzed reactions microwave irradiation catapults the reaction rates by order of magnitude and the rates of enzymatic reactions are also enhanced. 37 -41 R-(−)-mandelic acid is an important intermediate in the synthesis of various drugs.…”

Novel Hybrid Esterase‐Haloacid Dehalogenase Enzyme

“…Lipases (triacyl glycerol hydrolases EC 3.1.1.3) are one of the most commonly used enzymes in organic synthesis. A few applications of non‐aqueous enzymology including kinetic modeling have been investigated, mainly for hydrolysis,8 esterification,9–14 transesterification,9, 15, 16 and epoxidation 17, 18. Lipases are commercially readily available and show excellent enantioselectivity, broad substrate specificities to natural and unnatural esters of different structures, and good stability in various media ranging from aqueous to non‐aqueous organic solvents, and directed evolution is a key to this achievement 4, 19.…”

“…The thermal gradients and flow of heat is the reverse of those in materials heated by conventional means. Lipase‐catalyzed reactions are rather sluggish in nature; synergism with microwaves can be expected to enhance the rates of reactions 12, 14, 17. It has been reported that in a number of chemically catalyzed reactions microwave irradiation catapults the reaction rates by order of magnitude and the rates of enzymatic reactions are also enhanced 37–41…”