Study On The Synthesis Of Indole Compounds By Tandem Cycloaddition Reaction

Indole derivatives are widely found in nature.Many natural and synthetic compounds contain indole rings in their structures.The special biological activity of indole skeleton compounds has aroused the interest of chemists and pharmacists all over the world.More and more scientists are committed to the research of indole compounds.In this paper,a series of indole derivatives with potential biological activity were synthesized by domino[3+2]and[4+2]cycloaddition reactions.1.The[4+2]cycloaddition reaction of in situ generated 3-benzoylindole with chalcones and the similar reaction of 3-(indole-3-yl)maleimides with chalcones in a one-pot two-step method were studied.This reaction successfully providesd an extremely simple and efficient scheme for the synthesis of carbazole derivatives.The reaction has the advantages of easy availability of starting reagents,simple preparation,high efficiency and atomic economy.This reaction has potential applications in organic chemistry and medicinal chemistry.A total of 24 compounds were synthesized.The chemical structures of the synthesized carbazole derivatives were characterized by IR,HRMS,1H NMR and 13C NMR.The single crystal structure of one compound was determined by X-ray diffraction.2.The cycloaddition reactions of(E)-3-(1 H-indole-3-yl)-1-phenylprop-2-en1-one derivatives with various 3-indolyl methanol derivatives were studied.The cyclization reaction is of great significance in the synthesis and application of heterocyclic chemistry,and has potential application value in organic chemistry and pharmaceutical chemistry.It has the advantages of easy availability of reagents,mild reaction conditions,high yield,high diastereoselectivity,molecular diversity and atomic economy.A total of 37 five-membered ring compounds were synthesized.The chemical structures of the synthesized compounds were characterized by IR,HRMS,1H NMR and 13C NMR.The single crystal structures of the three compounds were determined by X-ray diffraction.3.The[4+2]cycloaddition reactions of(E)-3-(1H-indole-3-yl)-1phenylpropyl-2-en-l-one derivatives with various maleimides and the dimerization reactions of(E)-3-(1 H-indole-3-yl)-1-phenylprop-2-en-1-one derivatives were studied.We successfully synthesized 2-methyl-4-(4methylbenzoyl)pyrrolo[3,4-a]carbazole-1,3(2H,10H)-dione derivatives in high yield and high diastereoselectivity.The reaction has the advantages of easy availability of raw materials,simple reaction conditions,wide substrate range,satisfactory yield,and high diastereoselectivity.A total of 25 compounds were synthesized and their chemical structures were characterized by IR,HRMS,1H NMR and 13C NMR.The single crystal structure of two compound were determined by X-ray diffraction method.