“One pot” and selective synthesis of monoglycerides over homogeneous and heterogeneous guanidine catalysts

The selective synthesis of monoglycerides was carried out in one step starting from an equimolar mixture of unprotected glycerol and fatty methyl esters. This reaction was catalyzed at low temperature by supported guanidine catalysts either in a solvent or without. Whereas most alkaline hydroxides or carbonate catalysts lead to monoglycerides in a limited purity and an excessive corrosive waste production, we showed that supported guanidine derivatives afforded monoglycerides in high yield according to an environmentally friendly process. Moreover, at the end of the reaction, the solid catalyst was easily recovered by filtration and reused several times without notable change of reactivity.