Methoxytri Ethylene Glycol Research Articles

Chitosan- g-mPEG-supported palladium (0) catalyst for Suzuki cross-coupling reaction in water

A chitosan- g-mTEG (methoxy triethylene glycol)- or mPEG (methoxy polyethylene glycol)-supported palladium (0) catalyst was prepared for the Suzuki cross-coupling reaction in water. The catalyst showed excellent catalytic activity in the Suzuki cross-coupling reaction without additional phase transfer reagents due to the enhanced solubility of the organic substrate by PEG grafting. In addition, the catalyst could be reused up to five times with the catalytic activity being recovered easily after simple manipulations.

Regioselective synthesis of ethoxylated glycoside esters using beta-glucosidase in supersaturated solutions and lipases in organic solvents

Three ethoxylated glycosides, tetraethylene glycol beta-D-glucoside, tetraethylene glycol beta-D-xyloside, and methoxy triethyleneglycol beta-D-glucoside, were prepared via almond beta-glucoside-catalyzed (trans)glycosylation carried out in supersaturated solutions of glucose or p-nitrophenyl beta-D-xyloside and the respective polyethylene glycols. The products were isolated and further modified by enzymatic esterification with Candida antarctica and Mucor miehei lipases. The latter enzyme showed a much greater selectivity for the primary hydroxyl group on the polyethylene glycol chain of the glucoside substrate, thus enabling us to obtain exclusively the corresponding monoester, omega-O-oleoyl tetraethylene glycol beta-D-glucoside. Novozyme was used for the preparative synthesis of two other monoesters, 6-O-oleoyl (methoxy triethyleneglycol) beta-D-glucoside and omega-O-oleoyl tetraethylene glycol beta-D-xyloside. Two diesters, di-oleoyl tetraethylene glycol beta-D-glucoside and tetraethylene-bis(6-0-oleoyl glucoside) were also synthesized in good yields using this lipase. Copyright 1998 John Wiley & Sons, Inc.