The Studies Of Olefination Of Carbonyl Compounds

Organozincs are an important classic organometallics for organic synthesis. They have good reaction selection. A variety of functional groups may be tolerated in these organometallic reagents because of their moderate reactivity. They are widely applied in the construction of C-C bond.Our group first reported a novel dialkylation reaction of alkyl zinc iodides with aromatic aldehydes and an olefination reaction of benzyl zinc bromides with aromatic aldehydes respectively. In those papers, we discussed the reaction mechanism based on some experiment phenomena. The olefmation of benzyl zinc bromides with aromatic aldehydes, which has some theoretical means and good application expectation, has good stereoselectivity and regioselectivity.This thesis includes three chapters.Chapter one: The development of modern Carbonyl Olefmation.This chapter summarized the recent progress in the major methodologies of carbonyl olefmation in detail, which is one of the most fundamental transformations in organic synthesis, and compared the advantages and limitations of variety of carbonyl olefmation methods.Chapter two: Study on the Olefination of Functionalized Benzylzinc Halides with Cinnamic Aldehyde:In this chapter, we studied the olefination of functionalized benzylzinc halides with cinnamic aldehyde. The reaction conditions were discussed. In this section, seventeen compounds of 1,4-diphenyl-1, 3-butadienes were synthesized. Meantime, we further studied this reaction under microwave irradiation conditions and first introduced the concept of the solvent-free and no-catalyst in this reaction, expanded the olefination of organozinc halides reagents with aldehydes, enlarged the application scopes of this reaction.Chapter three: The studies of zinc dust assisted the green carbonyl olefination under thesolvent-free conditions.In this section, in the presence of Me₃SiCl, we first studied the zinc dust assisted olefination of benzyl bromide with carbonyl compounds under solvent-free and no-catalyst. We found this method could converse the carbonyl compounds into the E-alkene stereoseletively with good yields, which was an environment friendly synthetic method. The main advantages of this method were rapid reaction speed, high stereoselectivity, convenient operation and work-up.