Increased selectivity in the formation of the phenoxy ether of methyl lesquerolate over chloroalkyl-modified SBA-15-SO3H catalysts

A novel synthetic catalysis was developed for selective modification of useful bioproducts from the oil of Lesquerella fendlerii, an agricultural commodity of increasing importance. Modification of the surface of the solid acid catalyst SBA-15-SO3H with the chloroalkyl groups CH2CH2Cl, has improved the selectivity in the synthesis of the phenoxy ether of methyl 14-hydroxy-11-eicosenoate (methyl lesquerolate). A series of catalysts, SBA-15(EtCl)xSO3H where x = 0, 2, 4, 8, have been prepared and characterized by 13C CPNMR, surface properties, and elemental analyses. Selectivity increased with increased loading of the chloroalkyl group. This selectivity can be attributed to the decrease in the rate of conversion of the phenoxy ether to the Friedel–Crafts adducts. This study demonstrates synthetic approaches can develop novel catalysts to increase yields and selectivity for value-added bioproducts from new crops.

Graphical abstractPropylsulfonic acid-functionalized SBA-15 catalysts were used to prepare phenoxy ethers of methyl lesquerolate. Modification of the silica surface with chloroethyl groups increased the selectivity toward this product versus the formation of Friedel–Crafts alkylation products.Figure optionsDownload full-size imageDownload high-quality image (64 K)Download as PowerPoint slide