Resin-Bound Aminopropylimidazole-Decorated Dendrons and the Effect of an Unsubstituted Phenol Unit

Yael Shiloni, School of Chemistry, Tel-Aviv University, Tel-Aviv, Israel

Polystyrene-supported aminopropylimidazole-decorated dendrons,¹ denoted by Gn(A-Im) (with n signifying the dendron generation), have been proven to be highly efficient as catalysts for the Baylis-Hillman reaction, for instance the reaction of 4-nitrobenzaldehyde and methyl vinyl ketone (Scheme 1).²

Scheme 1. The Baylis-Hillman reaction between 4-nitrobenzaldehyde and methyl vinyl ketone, catalyzed by polystyrene-supported aminopropylimidazole-decorated dendrons, Gn(A-Im).

These catalysts were synthesized via solid-phase synthesis, which, in general, bears many advantages.³ However, we have recently decided to challenge the classic synthesis, previously employed in our group, and have formulated new synthetic pathways towards the synthesis of the coveted dendritic catalysts, of first and second generations, with all methods incorporating homogeneous steps to some extent.

This poster will portray the synthetic pathways employed for generating the first and second generation dendritic catalysts, G1(A-Im) and G2(A-Im), respectively.

The poster will also include the results obtained with the newly prepared catalysts in the model reaction abovementioned. Interestingly, the data points to the importance of an unsubstituted phenol unit in the catalytic structure.

References:

1. Dahan, A.; Portnoy, M. J. Polym. Sci. Part A: Polym. Chem. 2005, 43, 235-262.


2. Goren, K.; Portnoy, M. Chem. Commun. 2010, 46, 1965-1967.


3. Früchtel, J. S.; Jung, G. Angew. Chem. Int. Ed. Engl. 1996, 35, 17-42.