Synthesis Of Benzo[f]Carbazole And Porphyrins From Sulfonyl Hydrazide By Cu-Catalysis

Because of their highly efficient and broad-spectrum biological activity,nitrogen-containing heterocyclic compounds are widely used in medicine,agricultural chemicals and our life.Among of their,benzo[f]indazoles and cinnolines are very important heterocyclic compounds,and contain two nitrogen atoms in five-and six-membered ring.Their core skeletons are widely found in natural products and active molecules.benzo[f]indazole and cinnoline derivatives exhibit excellent biological activities such as anticancer,antiviral,bactericidal and anti-inflammatory.Therefore,great attentions from chemists have been paid to synthesis of such compounds.Over the past few decades,many effective methods have been developed.However,employment of expensive metal catalysts and harsh reaction conditions limited the application of these methods in organic synthesis,especially in drug synthesis.Therefore,the development of novel and efficient method for the direct synthesis of benzo[f]indazole and cinnoline derivatives with a variety of functional groups under mild conditions is highly desirable.In this paper,we disclosed two new methods for prepareation of benzo[f]indazole and cinnoline derivatives,respectively by using simple and readily available sulfonyl hydrazones as starting material and low-cost copper as catalyst.The contents are as follows:1)A novel and efficient strategy for the direct synthesis of benzo[f]indazoles via copper-catalyzed cascade reaction of sulfonyl hydrazides with 1,3-enynes under mild conditions has been developed.Under oxidant and base conditions,this method achieves the formation of two C–N bonds and one C–C bond in one pot,providing a series of benzo[f]indazoles in moderate to good yields with good functional group tolerance and remarkable regioselectivity.Mechanistic investigation elucidate the reaction involves a condensation of two reaction partners and followed by a Cu?II?-initiated radical tandem cyclization.2)We have disclosed a new and efficient mothed for synthesis of functionalized cinnolines via Cu?OAc?₂ catalysed tadom reactions from N'-?1-?2-?Ethynyl?aryl?ethy lidene?benzenesulfonohydrazides.This reaction provides a simple and mild avenue to functionalized Cinnolines with good yield by used Cu?OAc?₂ as catalyst,TBHP as oxidant,K₂CO₃ as base,mixture of DCE/CH₃OH?3:1?as solvent and under N₂atmosphere for 5 hours.