The Synthesis And Application Of Chiral Organocatalysts And The Research Of Cascade Reaction Combining Transition Metal And Organocatalysts

This dissertation includes two parts as follows:1) Novel chiral organicatalysts were synthesized from natural camphor and L-proline. Their applications in the catalytic asymmetric Michael reaction and Baylis-Hillman reaction were investigated.2) Novel Heck-Aldol cascade reaction was studied combing transition metals and orgranocatalysts.1. Synthesis of novel chiral organocatalysts and their applications in catalytic asymmetric reactionsIn this part, three novel chiral organicatalysts?-?have been designed and synthesized from L-proline and D-camphor. We explored asymmetric Michael reaction between ketone and (3-nitrostyrenes with?-?as catalysts and found that I can efficiently catalyze the reaction with high yield (66-91%) and high enantioselectivity (64-90%). Chiral products 21 were obtained with 75-90%yield and 69-91%ee with?as catalysts. Then new catalysts IV and V were rationally designed and synthesized to catalyze the Baylis-Hillman reaction. And IV can catalyze the reaction at room temperature with good yields (52-70%) and low enantionselectivity (43-48%ee). 2. Study of cascade reaction combining transition metal catalysis and organocatalysisIn recent years, the method of combing transition metal and organocatalysis has emerged as a promising strategy for developing new and valuable reactions, and attracted considerable attention. Novel Heck-Aldol cascade reactions were carried out smoothly combing palladium catalysts and aminocatalysts. On the optimal conditions,?,?-unsaturated aldehydes 30a-q(68-82% yield) and Heck-Aldol-Heck cascade reaction products 31a-n(66-81% yield) were obtained with satisfactory yield and excellent regio- and stereoselectivities from simple aryl iodide, propenol, and paraformaldehyde. The E-form of compound 31 was confirmed by NOE experiments.