The Application Of Cyclization Of 2-(2-bromoallyl)-1,3-dicarbonyl Compounds In The Synthesis Of Organic Functional Molecules

Many natural products contain furan or 2-cyclopentenone structure motifs. Chemists are committed to the development of various strategies to construct these molecules. It is one of the most significant progress in modern organic chemistry that synthetic researchers can gain acess to achieve the formation of a new C-X bond through carbon-carbon or carbon-hetero coupling easily. Many transition metals are frequently employed to mediate such convertions. With high catalytic efficiency and low catalytic loading, silver or palladium could display outstanding performance in coupling reactions. In this thesis, the intramolecular cyclization of 2-(2-bromoallyl)-1,3-carbonyl compounds mediated by Ag(I) to constrcuct furans and by Pd(0) to construct 2-cyclopentenone derivatives were displayed respectively. In detail, there were two main parts. The first part was selective synthesis of 2,3,5-substituted furans or 2,3,4-substituted furans mediated by Ag (I)/base or base only. With 15 compounds as starting materials,30 furan carboxylates were obtained successfully. The second part was oriented to the formation of 2-cyclopentenone derivatives and analogues catalyzed by Pd (0) through C(sp3)-H activiation.18 compounds were synthesized, among which 15 were the desired products. All the above final products were characterized by’H NMR,13C NMR, HRMS and IR. To the best of our knowledge, these strategies have not been reported previously. With mild reactive conditions, simple operation and wide scope of substrates, some small organic molecules with novel structure or special function and even complex natural products containing furan or 2-cyclopentenone are expected to be synthesized applying these methodologies.