Studies On Formation Of Cyclopropanes Based On MIRC Reaction And Studies On Heck Reaction In Room Temperature Ionic Liquids

This Dissertation focuses on study of Formation of Cyclopropanes based on MIRC reaction and study of Heck reaction in room temperature ionic liquids. It contains four parts as follows:Chapter 1. The developments of Domino reaction and its applications in total synthesis of natural products (Review)In this part, the definition and classification of domino reaction were briefly introduced. Then cationic, anionic, pericyclic, radical, transition metal catalyzed, enzymatic domino reactions and their applications in the total synthesis of natural products were also reviewed.Chapter 2. A high diastereoselectively formation of 1,2,3-trisubstituted cyclopropane derivatives based on MIRC reactionIn this part, the MIRC reaction and its applications in synthesis of cyclopropanes were reviewed at first. Then our efforts of synthesis of 1,2,3-trisubstituted cyclopropane derivatives based on MIRC reaction between lithium 1,3-dithiums and 1,4-diary vinyl epoxides were discussed in details. This reaction was supposed to be a domino conjugation addition-epoxide opening sequence. This methodology can be applied to the 1,4-diaryl vinyl epoxides system. In most cases, the diastereoselectivity ratio was as high as 95:5.Chapter 3. Studies on Heck reaction in room temperature ionic liquidsIn this part, a brief introduction of green chemistry, room temperature ionic liquids and Heck reaction were presented at first. Then our efforts of applying ionic liquids as solvents in Heck reaction were discussed in details, which is the classic C-C bond formation reaction, (a) Pd/C catalyzed intermolecular Heck reaction in room temperature ionic liquids accelerated by microwave heating were developed. This methodology shortened the reaction time to 1.5 min with a modest yield, (b)Benzofiiran and indole derivatives were synthesized by Pd-catalyzed intramolecular Heck reaction in room temperature ionic liquids. The reaction time was shortened, the reaction temperature was lowered and the yields were improved by applying room temperature ionic liquids as solvents.Chapter 4, The total synthesis of nature occurring flavonolignan 5 " -methoxy-hydnocarpinIn this part, the benzodioxanelignans and the methods to synthesize them are reviewed at first. Then our synthetic effort towards the nature occurring flavonolignan 5 " -methoxy-hydnocarpin was discussed. The flavonolignan was obtained in 8 steps starting from 3,4-dihydroxy benzaldehyde, 2,4,6-trihydroxyl acetophenone and 3,4,5-trihydroxy benzaldehyde, in which the I2 oxidative cyclization and Ag2O oxidative coupling were the key steps. This synthetic route is convergent and can be applicable to synthesis of other benzodioxanelignans.