Functionalization Of Nitrogen-containing Heterocyclic Compounds Catalyzed By Nitrogen Heterocyclic Carbene

As an important synthetic building block in the field of organic synthesis,nitrogen-containing heterocyclic compounds are commonly found in natural products,materials,pharmaceuticals and pesticide molecular skeletons.Due to their unique biological activity,these compounds have attracted the attention of organic synthesis.How to construct nitrogen-containing heterocyclic compounds with efficient and simple synthesis strategy has long been a hotspot and difficulty in this realm.As an important member of nitrogen-containing heterocyclic compounds,indole compounds' s highly efficient biological activity has been studied and used extensively.To realize the refinement of the indole-containing framework compounds and synthesize the novel indole derivatives have been a impotant subject in the field of organic synthesis.In recent years,organocatalyst is one of the research subject in organic catalytic field.As a rising star in organocatalyst,N-Heterocyclic carbene has been investigated extensively by researchers and develop rapidly due to its unique catalytic activating mode.The ?-position activation of the carbonyl compounds is one of the important activation modes of the N-Heterocyclic carbene-catalyzed all kinds of reactions.In this paper,there are two aspects were mainly studied.The one is catalytic activation of attached branched ?-position sp3 carbon atoms of indole for construction indole derivatives of novel structure,and the other is the research of its biological activity.1.Oxidative catalytic activation branch sp3 carbon of 3-methylindole-2-carbox-aldehyde under N-heterocyclic carbines catalysis and diphenoquinone as external oxidant offers an o-quinodimethane intermediate that react with trifluoroaceto phenone.This reaction provided a class of high productivity indole derivatives that containing six membered lactone,trifluoromethyl,spirocyclic carbon,which undergoes formal oxo-Diels-Alder cycloaddition in mild condition.Therefore,indole derivatives that are multi-functionalized and structure-innovated was obtained in a simple and efficient way.And it is successful to activate branch carbon of heterocyclic aryl aldehyde.Moreover,it provides a theoretical basis for the activated ?-position sp3 carbon atom of aromatic aldehydes.2.Bioassay of some of these target compounds synthesized have been investigated by using the turbidity method,the results indicated that the compound 3p showes good activity against Xanthomonas oryzae pv.oryzae about 100% both at 200 ?g/mL and 100 ?g/m L.Other compounds do not shows activities to these two kinds of plant bacteria.