| Popis: |
This thesis consists of five chapters. In Chapter 1 is referred the importance of fluoroalkene skeletons, together with general physical/chemical properties and availability of organofluorine compounds. In addition, precedent synthetic methods for the preparation of fluoroalkenes are presented. Chapter 2 describes an efficient chromium(II)-mediated reductive coupling reaction of various bromodifluoromethyl-containing molecules with aldehydes. It was revealed that the reaction proceeded very smoothly to afford the corresponding β-fluoroallylic alcohols in a highly stereoselective manner. It is particularly worth noting that (E)-β-fluoroallylic alcohols were exclusively given in the case of 3-(3-bromo-3,3-difluoropropanoyl)-2-oxazolidinone as a substrate, while (Z)-β-fluoroallylic alcohols were provided in the case of other substrates, such as 4-bromo-4,4-difluorobutylate, 3-bromo-3,3-difluoropropyl ether, and 1-bromo-1,1-difluoro-nonanes. Chapter 3 describes the unusual ring-opening reaction of gem-difluorocyclopropylstannanes, which were prepared via the radical hydrostannation of various gem-difluorocyclopropenes with n-Bu3SnH. Thus, on treating gem-difluorocyclopropylstannanes with MeLi, followed by quenching the reaction with various media, such as H2O, alcohols, carboxylic acids, and p-toluenesulfonamide, gave the corresponding β-fluoroallylic alcohols, ethers, esters, and amide in a highly Z-selective manner. Chapter 4 describes SN2’ substitution of β-fluoroallyl phosphates with organocopper reagents. It should be noted that various types of β-fluoroallyl phosphates reacted smoothly with various organoalkylcuprates, prepared from Grignard reagents, organolithium, organozinc reagents and CuCN, the corresponding terminal fluoroalkenes being obtained in a highly regioselective manner. Among thus obtained fluoroalkenes, fluorinated 1,7-dienes underwent a smooth ring-closing metathesis under the influence of Grubbs catalyst, providing the corresponding fluorinated cyclohexenes in high yields. In Chapter 5 is summarized the discussion in each chapter. |
