In this paper we compare two different reactions, aimed at the synthesis of 1,2-cyclohexanediol.Specifically: (a) the direct epoxidation and hydrolysis (dihydroxylation) of cyclohexene to trans-1,2-cyclohexanediol, with an aqueous solution of hydrogen peroxide, and (b) the hydrogenation of catecholto a mixture of cis and trans-1,2-cyclohexanediol, in an attempt to establish green protocols for the syn-thesis of diols. Both reactions, the dihydroxylation of cyclohexene and the hydrogenation of catechol,were carried out without organic solvents. In the former case, an unprecedented 97.4% yield to the glycolwas obtained, by selecting proper reaction conditions and using a tungstic acid/phosphoric acid catalyst,in a biphasic system with a phase-transfer agent. In the second approach, a heterogeneous alumina-supported Ru(OH)xcatalyst was used, and a 90% yield to the glycol was obtained. A comparison of thetwo processes allowed to show the lower environmental impact of the catechol hydrogenation route.
C. ANTONETTI, A.M. RASPOLLI GALLETTI, P. ACCORINTI, S. ALINI, P. BABINI, K. RAABOVA, et al. (2013). Two alternative routes for 1,2-cyclohexanediol synthesis by means of green processes: Cyclohexene dihydroxylation and catechol hydrogenation. APPLIED CATALYSIS A: GENERAL, 466, 21-31 [10.1016/j.apcata.2013.06.023].
Two alternative routes for 1,2-cyclohexanediol synthesis by means of green processes: Cyclohexene dihydroxylation and catechol hydrogenation
RAABOVÁ, KATERINA;ROZHKO, ELENA;CALDARELLI, AURORA;RIGHI, PAOLO;CAVANI, FABRIZIO;
2013
Abstract
In this paper we compare two different reactions, aimed at the synthesis of 1,2-cyclohexanediol.Specifically: (a) the direct epoxidation and hydrolysis (dihydroxylation) of cyclohexene to trans-1,2-cyclohexanediol, with an aqueous solution of hydrogen peroxide, and (b) the hydrogenation of catecholto a mixture of cis and trans-1,2-cyclohexanediol, in an attempt to establish green protocols for the syn-thesis of diols. Both reactions, the dihydroxylation of cyclohexene and the hydrogenation of catechol,were carried out without organic solvents. In the former case, an unprecedented 97.4% yield to the glycolwas obtained, by selecting proper reaction conditions and using a tungstic acid/phosphoric acid catalyst,in a biphasic system with a phase-transfer agent. In the second approach, a heterogeneous alumina-supported Ru(OH)xcatalyst was used, and a 90% yield to the glycol was obtained. A comparison of thetwo processes allowed to show the lower environmental impact of the catechol hydrogenation route.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
