engleski

Organocatalytic activity of the new guanidine derivatives

Guanidines have been widely recognized as powerful organocatalysts in a variety of organic reactions.[1] This was attributed to their high intrinsic basicity[1, 2] and affinity to form hydrogen bonds with various functional groups.[3] We have recently shown that the presence of dimethylamino subunit within the side chains can increase the basicity in both gas-phase and solution.[4, 5] Similar effect on the basicity is also expected when other powerful proton accepting groups are included in the structure. Here we report on the synthesis of novel guanidine derivatives with either pyridine or carbonyl containing subunit (amido or ester group) within at least one alkyl side chain. Organocatalytic activity of the newly prepared compounds was tested in Knoevenagel reaction and in transesterification of the sunflower oil with methanol. Their activity was compared to the results obtained by using recently synthetized dimethylaminopropyl substituted guanidines [5] and selected commercially available amines and guanidines often used as catalysts in the same type of reactions.

guanidines; organocatalytic activity; Knoevenagel reaction; transesterification

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