Additive-Free Baeyer–Villiger Oxidation of Cyclic Ketone Catalyzed by Carboxylic-Functionalized Poly(Ionic Liquids) and Polyoxometalate Ionic Self-Assemblies

Abstract

Two carboxylic functionalized poly(ionic liquids) and polyoxometalate ionic self-assemblies with tunable amphiphilic and oxidative activity and porous structure were designed and synthesized. They were used as efficient heterogeneous catalysts exhibiting excellent catalytic activity and quite stable reusability in additive–free Baeyer-Villiger oxidation of cyclic ketones, directly using 30% H2O2 solution in liquids–phase. Under optimum conditions, the corresponding lactones were obtained with yields ranging from 59.6 to 90.5%. The unique combination of carboxylic group with polyoxometalate anion, amphiphilic property, and porous structure is revealed to be responsible for their excellent catalytic performances in oxidation.

Functional Nano-Objects by Electrostatic Self-Assembly: Structure, Switching, and Photocatalysis

“…The trivalent Keggin anion K 3 PW 12 O 40 and the Keggin anion H 4 SiW 12 O 40 , generate network-like structures in combination with a cationic carboxylic functionalized poly (ionic liquid) by electrostatic self-assembly, which acts as heterogeneous catalyst for the additive-free Baeyer-Villiger oxidation of cyclic ketones ( Li X. et al, 2020 ). H 3 PW 12 O 40 -assemblies show a higher catalytic activity than H 4 SiW 12 O 40 -assemblies but both ionic-liquid-POM assemblies show higher conversion with H 2 O 2 , selectivity, and yield than the POM alone in solution.…”

Cobalt-Tetraamide-Phthalocyanine Immobilized on Fe3O4/Chitosan Microspheres as an Efficient Catalyst for Baeyer–Villiger Oxidation

“…Baeyer–Villiger (B–V) oxidation is a significant organic reaction for converting ketones to the corresponding lactones or esters, which are indispensable intermediates for the synthesis of antibiotics, steroids, pheromones, and other fine chemicals in laboratory and industrial chemistry. , In the traditional stage of B–V oxidation, the mainly used oxidants are peracids, such as persulfuric acid, perbenzoic acid, m -chloroperbenzoic acid ( m -CPBA), and peroxide (H 2 O 2 ). , However, peracids are usually expensive, dangerous, and difficult to transport and store. High concentration of hydrogen peroxide has a good oxidation effect on the B–V reaction, but the water produced by the reaction is prone to hydrolyze lactones, and high concentration has a higher risk in industrial production. , Based on the above-mentioned factors, the harmfulness and high economic cost of peroxide limit its practical application.…”

“…1,2 In the traditional stage of B−V oxidation, the mainly used oxidants are peracids, such as persulfuric acid, 1 perbenzoic acid, 3 mchloroperbenzoic acid (m-CPBA), and peroxide (H 2 O 2 ). 4,5 However, peracids are usually expensive, dangerous, and difficult to transport and store. High concentration of hydrogen peroxide has a good oxidation effect on the B−V reaction, but the water produced by the reaction is prone to hydrolyze lactones, and high concentration has a higher risk in industrial production.…”

Green Oxidation of Ketones to Lactones with Oxone in Water

“…Due to transannular strain, 8-membered lactones are more difficult to be constructed and easier to be opened by hydrolysis. Revealingly, investigations on new procedures for BV oxidation of cyclic ketones are often limited to 5–7 membered lactones , or admit their failure when applying the developed general method to 1d . On the other hand, except for the use of peracids in halogenated solvents, reports claiming oxidation of 1d to 2d with high conversion degrees and yields are elusive on 2d isolation or describe very small-scale procedures. , And as far as Oxone, 1d is reported to be oxidized to 2d by Oxone supported on silica gel in DCM with 93% conversion, but 2d is isolated, impure, without a specifying procedure and yield .…”