Study On Carbonyl Olefination And Synthesis Of Homoallylic Bromide

Carbon-carbon double bonds and homoallylic bromide are both the invaluablestructures in organic synthesis, so it benefits to develop a convenient and efficientmethod to construct these structures.The thesis consists of the following two sections.1. Research on the reaction of carbonyl olefination. The widely available carbonylcompounds react with organozinc reagents in the presence of diphenyl phosphite to givethe corresponding olefins in good to excellent yields. And a range of conjugated dienes,unsaturated esters and conjugated enynes could be readily obtained in the mildconditions. The yields of both electron-donating and electron-withdrawing groupsemployed in benzene rings are good to excellent. Moreover, thiophene and furanheterocycles participate efficiently in the reaction. E-olefins could be obtained as thepredominant products by the reaction of aldehydes with organozinc reagents in highstereoselectivity, but with low yields. We have appended the work of probing themechanism for this olefination process and given the possible mechanism.2. Research on reaction of synthesis of homoallylic bromide. When cyclopropylGrignard reagents react with carbonyl compounds in the presence of diethyl phosphite,the cyclopropyl undergos a ring-opening reaction to afford E-homoallylic bromide withexcellent yields.