Study On Isocyanide Based Multicomponent Reactions

In this dissertation, the research was mainly focused on isocyanide based multicomponent reactions to synthesize pharmacologically and biologically active heterocyclic compounds. There are three parts in this thesis which were described as follow:In the first part, the one-pot procedure to synthesize hydroxylthioxopyrrolidines was discussed. In the mixed solvent of MeCN and H2O, a simple and efficient one-pot multicomponent reaction between isocyanide, benzo[d]thiazole-2-thiol, and 2-benzylidenemalononitrile derivatives was developed for the synthesis of a series of potentially biologically important hydroxylthioxopyrrolidines. The reactions were carried though at room temperature and the products could be abtained within a few hours in satisfied yields.In the second part, we discovered a highly efficient method to synthesize formamidine scafford promoted by ultrasound irradiation. The reaction was carried out at 50 oC without any catalyst and the products were obtained in high yield (up to 95 %).In the third part, an efficient one-pot procedure was discoveried for the construction of furo[2,3-b]indole derivatives via a combination of the traditional I-MCR and the copper-catalyzed intramolecular Ullmann reaction. Firstly, the 2-amino furan derivatives were obtained from the reactions between 2-halobenzoaldehydes, 4-hydroxycoumarins and isocyanides. Then the furo[2,3-b]indole derivatives were obtained via intramolecular Ullmann reaction catalyzed by CuI. The reaction condition of the latter step was optimized particularly and the product was obtained in good yield under the catalyzation of CuI within 24 hours utilizing L-proline as the ligand and K2CO3 as the base. In these reactions, the furo[2,3-b]indole derivatives with complex structure and pharmacological and biological activities were synthesized easily and efficiently via the combination of the two different kind of reactions. The reaction can be produced in one-pot manner with no need to separate the intermediate and the catalyst was cheap and easily available. In this reaction, both the 2-iodobenzaldehyde 2-chlorobenzaldehyde and could be performed as good substrates.