Synthesis Of New Cinchona Alkaloids Derivatives Catalysts And Their Catalytic Reactions

In the present study of asymmetric catalytic synthesis, Phase-transfer catalysis is a very useful approach that typically involves simple experimental operations, mild reaction conditions, inexpensive and environmentally benign reagents and solvents, and large-scale reactions. Synthesis of optically activeα-amino acids has been realized by using chiral phase-transfer catalysts and N-(diphenylmethylene)-glycine tert-butyl ester as substrates. Like other kinds of asymmetric catalytic reactions, design and synthesize efficient catalysts are the key part to such reaction.Through analysis the realationship of cinchona alkaloids quaternary ammonium salts class phase transfer catalyst catalytic activity with their stereo structure. It was found that the electronic effects and the influence of steric hindrance is piay an important role in their catalytic activity. under the guidence of this basic ideology, a series of efficient phase transfer catalysts has been synthesised.1. N-(diphenylmethylene)-glycine tert-butyl ester has been synthesised as substrates of enantioselective alkylation reaction.2. In consideration of the electronic effects and the influence of steric hindrance, by introducing benzyl into 9-OH of cinchona derivatives, four new kind of chiral phase-transfer catalysts has been synthesised and identified by 1H- NMR, IR, melting point and specific rotation.3. The catalytic activity and stereoselectivity of four catalysts were evaluated using N-(diphenylmethylene)-glycine tert-butyl ester as substrates. The highest chemical yields was 69% and the optimal enantioselectivity was 90%ee.4. Explore the new reusable catalyst using for asymmetric dihydroxylation reaction.