Synthesis And Application Of Microgel-supported Chiral Proline And Its Derivant

Z-proline and its derivants were a kind of efficient catalysts which were used in asymmetric catalyzed Aldol reaction, Michael addition, Mannich reaction and so on. Good catalytic result was obtained. Microgel is a kind of soluble support, which was used in organic synthesis. Supported proline and its derivants have good catalytic performance and easy recovered. We firstly prepared five Microgel-supported proline derivants catalysts, studied the catalytic performance of these catalysts.Z-Boc-hydroxyproline used as chiral material, reacted with chloromethylstyrene to give proline derivants with double bond. After a series of reactions, five kinds of proline derivatives chiral monomers were obtained. These monomers were copolymered with styrene and DVB. Then reacted with TFA, Boc was removed, five kinds of soluble Microgel-supported proline derivatives were prepared.Five kinds of Microgel-supported catalysts were used to catalyze Aldol reaction. The catalyst Id (Microgel-supported Proline sulfonamide) had the best catalytic performance for3-nitrobenzaldehyde and acetone Aldol reaction as a template. The effect of temperature, solvent, and the equivalent of catalyst were discussed. The yield is98.4%, the ee value reached96.2%in the condition of acetone as solvent, catalyst equivalent6mol%, room temperature and reacted120hours. Using this conditions, catalyst1d catalyzed the Aldol reaction of different aldehydes with acetone to give yield (0.25～98.4%) and ee value(29.8～96.2%). After5times of catalyst1d repeated use, the yield and ee values were not significantly decreased.We preliminary studied the catalytic performance of Mannich reaction and Michael addition reaction.1d had the better catalytic performance for the Mannich reaction of acetone and imine with yield of31～82%in five kinds of microgel-supported proline chiral catalysts. But there were much by-products. Using THF as the solvent,1d as the catalyst, the yield of Mannich reaction of acetophenone and imine was5～25%. Microgel-supported proline derivatives chiral catalyzed Michael addition reaction, the catalytic effect was not ideal with yield of5～12%.Polymer microgel-supported proline derivatives catalysts efficiently chiral catalyzed Aldol reaction with good catalytic activity and enantioselectivity. They had lower catalytic performance on Mannich reaction and Michael addition reaction.