27153-55-5Relevant articles and documents
Monoterpenes etherification reactions with alkyl alcohols over cesium partially exchanged Keggin heteropoly salts: effects of catalyst composition
da Silva, Márcio José,Lopes, Neide Paloma Goncalves,Ferreira, Sukarno Olavo,da Silva, Rene Chagas,Natalino, Ricardo,Chaves, Diego Morais,Texeira, Milena Galdino
, p. 153 - 168 (2020/07/21)
In this work, cesium partially exchanged Keggin heteropolyacid (HPA) salts were prepared, characterized, and evaluated as solid catalysts in monoterpenes etherification reactions with alkyl alcohols. A comparison of the activity of soluble HPAs and their insoluble cesium salts showed that among three different Keggin anions the phosphotungstate was the most efficient catalyst. Assessments on the effects of the level of the protons exchange by cesium cations demonstrated that Cs2.5H0.5PW12O40 solid salt was the most active and selective phosphotungstate catalyst, converting β-pinene to α-terpinyl methyl ether. The influences of the main reaction parameters such as reaction temperature, time, catalyst load, substrate nature (i.e., alcohols and monoterpenes) were investigated. We have demonstrated that the simultaneous presence of the cesium ions and protons in the catalyst plays an essential role, being the 2.5–0.5 the optimum molar ratio. The Cs2.5H0.5PW12O40 salt was efficiently recovered and reused without loss of catalytic activity. Graphic abstract: [Figure not available: see fulltext.]
Fe(III)-catalyzed α-terpinyl derivatives synthesis from β-pinene via reactions with hydrogen peroxide in alcoholic solutions
Da Silva,Carari,Manoel Da Silva, Adalberto
, p. 10529 - 10536 (2015/01/30)
In this study, a novel and environmentally benign Fe(iii)-catalyzed terpinyl derivatives synthesis using hydrogen peroxide in alcohol solutions (i.e. methyl, ethyl, propyl, isopropyl and butyl alcohols) was investigated. The use of Bronsted acid catalysts was avoided and β-pinene was used as the starting reactant. High conversions (ca. 90%) and combined selectivities for the α-terpineol and terpinyl alkyl ethers (ca. 70-73%) were obtained when Fe(NO3)3 was used as the catalyst. The role of each component catalyst system was studied with special focus on the solvent. The use of a biodegradable and renewable origin solvent (ethyl alcohol), which was added to an inexpensive and mildly toxic catalyst and a green oxidant are the main positive features of this process.
SOLVOLYTIC DISPLACEMENT OF ALKYL HALIDES BY METAL SALTS. PREPARATIVE PROCEDURES FOR ALLYL-, BENZYL- AND TERTIARY ALKYL-OXY DERIVATIVES USING THE ZINC SALTS
Gurudutt, K. N.,Ravindranath, B.,Srinivas, P.
, p. 1843 - 1846 (2007/10/02)
Reaction of allylic, benzylic and tertiary alkyl halides with zinc oxide in protic solvents leads to the formation of the corresponding alcohols, ethers and esters in good yields.The scope and limitations of this reaction have been examined.The possible involvement of ion quadruplets in the reaction is suggested.
