Study On Cycloaddition Reaction Of 1,3-Indanediones

1,3-Indanedione is one of typical cyclic 1,3-dicarbonyl compounds with one methylene unit,two carbonyl groups and fused phenyl ring.Thus,it has three contiguous reactive electrophilic and nucleophilic sites.On the other hand,1,3-indanedione undergoes homopolymerization to form several cyclic compounds with polycarbonyl groups under acidic or basic medium.2-Arylidene-1,3-indanediones derived from condensation of aromatic aldehydes with 1,3-indanedione are also reactive ?,?-unsaturated carbonyl compounds Therefore,1,3-indanedione has diverse reactivities and is the key substrate in domino multicomponent reactions.It has been widely employed to construct various spiro,bridged and fused cyclic compounds.In recent years,many achievements on multicomponent reactions involving 1,3-indanedione for syntheses of biologically important indanone-containing carbocyclic and heterocyclic compounds were successfully developed.In this paper,we investigated severaldomino cycloaddition reactions of 1,3-indanedione and synthesized vasrious novelindanone-fused and spiro polycyclic compounds1.The base-promoted domino reaction of indane-1,3-dione,aromatic aldehyde and N-benzylpiperidinone affordeda mixture of the indanone-fused 3-azabicyclo[3.3.1]nonane derivatives in high yields.By using different molecular ratio of indane-1,3-diones in the reaction,two kinds of bridged cyclic compounds with different relative configurations were successfully obtained.All products were characterized by IR,1H NMR,13C NMR,HRMS spectroscopy.The tensingle crystal structures were determined by X-ray diffraction method2.The base-promoted[4+2]cycloaddition reaction of indane-1,3-dione and 3-phenacylidene-2-oxindole resulted ina unique polycyclic bicyclo[2.2.2]octane derivatives containing bridged-and spiro-indanone scaffold in moderate to good yields.The obtained products usually have low solubility in common solvents because of the presence of hydroxyl,they can be converted to acetates with higher solubilityby actylation with acetic anhydride.The reaction mechanism included basic catalyzed cyclotrimerization to give active cyclic 1,3-diene and sequential Diels-Alder reaction with 3-phenacylidene-2-oxindole.All products were characterized by IR,1HNMR,13C NMR,HRMS spectroscopy.The six single crystal structures were determined by X-ray diffraction method.3.A unique base-promoted domino cycloaddition sequence of 1,3-indanedione and unsaturated carbonyl compounds is investigated.This reaction showed high molecular diversity.In the presenc of triethylamine,the reaction of 1,3-indanedione and 3-phenacylidene-2-indolineone in ethanolafforded carbamato-substitued indeno[1,2-a]fluorene-7,12-dione.In the presence of DABCO,the reaction in acetonitrile gave corresponding amino-substitued indeno[1,2-a]fluorene-7,12-diones in good yields.The reaction procceded with base promoted dimerization of 1,3-indanedione,Michael condensation,annulation,aromatization and the ring-opening of indolin-2-one.The domino reaction of 1,3-indanedionewith common chalcones also resulted in benzoyl-substituted indeno[1,2-a]fluorene-7,12-diones.In the presence of triethylamine,the domino reaction of salicylaldehyde with indane-1,3-dione resulted in the novel polycyclic cmpounds with nine-membered lacton.All products were characterized by IR,1H NMR,13C NMR,HRMS spectroscopy.The twelve single crystal structures of were determined by X-ray diffraction method.