Monolacunary K8SiW11O39-Catalyzed Terpenic Alcohols Oxidation with Hydrogen Peroxide

Cesium‐Exchanged Lacunar Keggin Heteropolyacid Salts: Efficient Solid Catalysts for the Green Oxidation of Terpenic Alcohols with Hydrogen Peroxide

“…Silicotungstate lacunar salt previously demonstrated to be an active catalyst in oxidation reactions; K 8 SiW 11 O 39 efficiently catalyzed the borneol oxidation with H 2 O 2 to camphor . Although a different substrate (i. e., secondary, saturated and cyclic alcohol), and a different solvent (dimethylacetamide) have been used in that work, K 8 SiW 11 O 39 was an effective catalyst and the oxidations reactions achieved a high TON …”

“…There is an aspect still less exploited in the literature; the vacancy created on the coordination sphere of the tungsten or molybdenum atoms present in the structure of heteropolyanion, generate potentially active catalysts, even without the introduction of transition metal cations . Recently, potassium‐exchanged lacunar HPA salts demonstrated to be highly active in oxidation reactions of borneol, a secondary terpenic alcohol that has not double bonds . These oxidative processes become even more attractive when performed with an inexpensive and environmentally friendly oxidant (i. e., hydrogen peroxide).…”

One-pot synthesis at room temperature of epoxides and linalool derivative pyrans in monolacunary Na7PW11O39-catalyzed oxidation reactions by hydrogen peroxide

“…The reaction conditions were chosen according to the literature. 1 The Na 7 PW 11 O 39 catalyst was more active than the lacunar (Na 7 PW 11 O 39 and mainly Na 8 SiW 11 O 39 ) or saturated salts (Na 3 PW 12 O 40 ) ( Fig. 6a).…”

“…The oxidation of terpenic alcohols, which are an abundant, renewable and attractive raw material, provide compounds useful for the synthesis of ne chemicals, fragrances, perfumes, and agrochemicals. 1,2 Linalool is a tertiary alcohol whose cyclization derivatives and epoxides are highly valuable due to their chiral building blocks for the synthesis of drugs. 3,4 The cyclization of linalool is an intramolecular process that results in the formation of tetrahydropyran and tetrahydrofuran derivatives, which are compounds with potential biological activity.…”

“…13 Among the various catalysts used in oxidations with hydrogen peroxide, polyoxometalates should be highlighted due to their high compound versatility that has been effective in homogeneous and heterogeneous processes. [14][15][16] Several heteropolyacids have redox properties that characterize them as an efficient catalyst in oxidation reactions with oxygen or hydrogen peroxide. 17 Keggin heteropolyacids (HPAs) are the most used polyoxometalates in catalysis.…”