吡唑并[1,5-a]吡啶骨架化合物之合成與芳香基取代反應之探討

Abstract

This thesis is divided into two parts. One part is the synthesis of compounds with pyrazolo[1,5-a]pyridines skeleton; the other part is aromatic substitution via palladium-catalyzed and C-H bonds activation on pyrazolo[1,5-a]pyridines. In chapter two, we proposed that pyrazolo[1,5-a]pyridines were synthesized by the reaction of enediynones with hydrazine, followed by addition of copper(I) chloride. This reaction is via copper(I) and the enynylpyrazole intermediate to form a copper(I) complexes, then further generated products. It is uncommon way in the study of the reaction mechanisms of literatures. In chapter three, the gold-catalyzed cyclization of eneynylpyrazoles to pyrazolo[1,5-a]pyridines is described. The conditions reported in chapter two was optimized to react with catalytic reagents, at room temperature in a shorter reactive time to generate the cyclized products. In chapter four, electrophilic cyclization of eneynylpyrazoles to pyrazolo[1,5-a]pyridines which were contained halogen groups. This synthetic method is not only a effective synthesis of pyrazolo[1,5-a]pyridines with halogen group of the product, but also try to further reacts by Suzuki reaction to generate different aryl-substitution products. In chapter five, the palladium-catalyed aryl-substitution with different conditions can be reacted in pyrazolo[1,5-a]pyridine ring of 3 or 7 position. It could be applied to the syntheses of a variety of substrates in many areas.