Study On Lewis Base Promoted Tandem Michael/Cyclization

Tandem or domino cyclization is a highly efficient way to obtain potential hand-shaped central compounds by one-pot.Among them,Tandem Michael/cyclization promoted by Lewis base is one of the common methods to construct various complex structural compounds such as spiro-,bridged-and polycyclic ring systems.Therefore,many researchers have designed many novel synthesis routes through series cyclization reaction.Based on this,a series of spirocyclic,aromatic and bridged ring compounds were synthesized by using Lewis bases promoted domino Michael/cyclization reactions in this paper.1.The Michael addition of 3-methyleneindolones and 5,5-dimethylcyclohexanedione to active methylene compounds was studied under the catalysis of DBU.Three-component reactions of the active methylene compounds,isatins or aromatic aldehydes and ammonium acetate in mixed solvents of toluene and methanol resulted in dispiro[indoline-3,2’-quinoline-3’,3"-indoline]or dispiro[indoline-3,2’-pyrrole-3’,3"-indoline]derivatives with good diastereoselectivity.A total of 28 compounds have been synthesized.When the isatin in the three components was replaced by aromatic aldehyde,the diastereoselectivity of the reaction was poor,and two different diastereomeric spiro[indole-3,3’,quinolines]were obtained in various molecular ratios.A total of 23 spiro[indole-3.3’-quinolines]were synthesized.The chemical structures of 51 spirooxyindole-containing compounds were characterized by IR,HRMS,1H NMR and 13C NMR,and the single crystal structures of 4 compounds were determined by X-ray diffraction.2.The domino Michael/Michael/cyclization/elimination/ring opening reaction of 1-phenylacetyl-4-(N,N-dimethylamino)pyridinium bromide with oenol-chalcone catalyzed by TMD was studied.This reaction provides a very simple and efficient method for the synthesis of tetrasubstituted and pentasubstituted benzene derivatives.This reaction not only provides a convenient method for the synthesis of polyfunctional benzene derivatives,but also further excavates the synthetic value of ylide pyridine salt.The chemical structures of 22 polysubstituted benzene compounds were characterized by IR,HRMS,1H NMR and 13C NMR,and the single crystal structures of the two compounds were determined by X-ray diffraction.3.The domino Michael/cyclization of 9-hydroxy-5H-benzo[7]cyclene-5-one derivatives and N-substituted Maleimide in the presence of DABCO was studied.The novel bridged seven-membered ring compounds were successfully synthesized.This method has the advantages of simplicity,high efficiency and high yield,and provides an effective method for the synthesis of natural products and drugs with bridged ring framework.The chemical structures of 15 bridged seven-membered ring compounds were characterized by IR,HRMS,1H NMR and 13C NMR,and the single crystal structure of one compound was determined by Xray diffraction.