Palladium-Catalyzed Ring-Opening Of Gem-Difluorinated Cyclopropanes

Fluorine-containing functional groups into agrochemicals,pharmaceuticals,and materials has become common practice due to the superior physicochemical and bioactivity characteristics which the fluorine atom can provide.Among them,monofluoroalkenes are one of the significant scaffolds as a peptide bond mimic in drug discovery,medicinal chemistry,and high-performance materials.In our work,we focus in syntheses of monofluoroalkenes from the reaction of gem-difluorinated cyclopropanes though carbon-carbon/carbon-flour bonds cleavage.As a category of electrophile gem-difluorinated cyclopropanes can react with carbon nucleophilic and leads to ring opened to form new C-C bond.On the other side,C-F bond activation by palladium catalyzed of gem-difluorinated cyclopropanes through cleavage of C-F are come in top practice approach to forming monofluoroalkenes derivatives with high functional group tolerance.In chapter two,we presented an example of palladium-catalyzed Suzuki cross-coupling of gem-difluorinated cyclopropanes with boronic acids,providing the corresponding ary-lated/alkenylated/alkylated 2-fluoroallylic scaffolds.This new approach has good functional group compatibility for both gem-difluorinated cyclopropanes and boronic acids,thus,an array of syn-thetic building blocks of monofluoroalkene scaffolds including conjugated fluorodiene and skipped fluorodiene gave good yields with high Z-selectivity.Moreover,further hydrogenation was described for monofluoroalkene,whereas the corresponding alkyl fluoride was constructed.In chapter three,we released the Cu/Pd-Catalyzed cis-borylfluoroallylation of alkynes for the synthesis of boryl-substituted monofluoroalkenes,providing a modular and general tactic to mono-fluorinated alkenes scaffolds with high regio-and stereoselectivity(Z/E).Moreover,an ar-ray of synthetic building blocks can be generated by downstream transformation.The borylative difunctionalization of alkene has emerged as a powerful approach to syn-thesize highly functionalized molecules.In chapter four,we provided an example of three-compo-nent reaction of gem-difluorinated cyclopropanes with alkenes and B2pin2,providing the corre-sponding mono-fluoroalkenes scaffolds with high regio-and stereoselectivity.Moreover,an array of synthetic building blocks can be obtained by transformation of the boron group.