Transition Metal-Free Functionalization Of Enaminone ?-C-H Bond And Tandem Annulation Reactions

Enaminones possess featured and diverse reactivities,and exhibite widespread application in organic synthesis.This thesis reports our research works in the transition metal-free cross coupling of the enaminone?-C-H bond and the tandem annulation reactions of enaminones in the synthesis of different organic products,covering three different sections of work.In the first section,we have realized the synthetic methods toward acyloxyl enaminones and 3-acyloxyl chromones via the?-C-H acyloxylation reactions of enaminones.Without using any catalyst or additive,the N,N-dimethyl enaminones functionalized with o-hydroxyphenyl react with bisaroyl peroxides to give 3-acyloxyl chromones via tandem C-H acyloxylation and chromone annulation.Under identical conditions,acyloxyl enaminones are producted by employing other conventional N,N-disubstituted enaminones.In the second section,we have explored and accomplished the synthesis of full subustituted pyrazoles via the tandem reactions of enaminones and sulfonyl hydrazines in water medium.Using NH₂-enaminones and sulfonyl hydrazines as starting materials,in the presence of I₂/TBHP and water medium,the full substituted pyrazole are synthesized via tande C-H sulfonylation and pyrazole annulation.In addition,the isotopic experiement using 15N labeling confirmed the C-N bond cleavage in the reaction,disclosing new application in the green synthesis of heterocycles.In the third section,we have achieved the selective synthesi of N₂-sulfonyl1,,2,3-triaozlesandN₂-H-1,2,3-triazolesviatheannulationreactionsof enaminone/enaminoesters and tosyl azide.With the substrates of NH₂-enaminones and tosyl azide,the water-mediated synthesis of N₂-sulfonyl 1,,2,3-triaozles are synthesized involving TMEDA-catalyzed functionalization of the enaminone?-C-H bond.By modifiyingthe catalyst loading,theselective formationof N₂-H-1,2,3-triazoles are observed by using DMSO as medium.