Study On Palladium-free Sonogashira Coupling Reactions

This thesis contains four parts, which mainly described the Sonogashira reactions catalyzed by CuI, Sm system and the cyclic coupling reactions to synthesize biindoles. The first part is about the Sonogashira reactions which were carried out to provide the corresponding coupling products in satisfactory to good yields by using CuI/8-hydroxylquinoline catalytic system. Noteworthy is that the bifunctional copper catalyst was successfully applied in this alkynylation reaction for the first time.The second part is about the alkynylation coupling reactions catalyzed by ligand-free iron/copper cocatalyst. Catalytic activity and loading have been investigated. Under the optimized conditions, the reactions were smoothly carried out to provide the corresponding coupling products in good yields. Noteworthy is that this low-cost effective and environmentally friendly protocol was the first to be employed in Sonogashira reaction.The third part is about ligand-free Samarium powder catalyzed cross-coupling reactions of aryl halides with terminal alkynes which were carried out in PEG600 to provide the corresponding coupling products in considerable yields. The catalytic activity, loading and the ratio of the two substrates have been investigated, and under the optimized conditions, a series of iodobenzenes and alkynes were tested. The effects of the substituted groups were also studied, and a prelimary research was made for the study of the mechanism.The fourth part is about the the synthesis of 1H, 1'H-2, 3'-biindole-3-carbonitrile via the one-pot cyclic coupling reaction between 2-iodoaniline and 3-(1H-indol-3-yl)-3-oxopropanenitrile catalyzed by CuI/utropine. After the optimizing of the conditions, different 3-(1H-indol-3-yl)-3-oxopropanenitriles were investigated under this conditions.