Synthesis Of 1-Naphthols?2-Pyrones And 3,3'-bisindoles Via Domino Reactions

The domino reaction refers to the combination with two or more steps transformation reaction in one pot without separation of reaction intermidates.Therefore,such reaction features simple operation,environmental friendliness,and high selectivity.In recent years,the domino reactions as efficient tools for synthesizing complex structures have attracted extensive attention in the field of organic synthesis.In this dissertation.three types of 1-naphthols,2-pyrones and 3,3'-diindoles were synthesized respectively via domino reactions by using yne-allenones,arylglyoxals and2-indolylmethanols as the corresponding synthons.This dissertation consists of the following four parts.In the first part,the domino reactions of yne-allenones and arylglyoxals were independently summarized and 2-indolylmethanols were acted as building blocks to afford fused indoles.On the basis of these reports,the basis and key contents of this thesis were provided.In the second part,the catalyst-free benzannulation of yne-allenones was reported,which accessed a series of new iminated 1-naphthol derivatives.The present transformation can be compatible with various functional groups of yne-allenones and amines including aromatic and alkayl conuterparts,and features high stereoslectivity,atom-economy and bond-forming efficiency.During the reaction process,yne-allenones underwent intramolecular[2+2]cycloaddition and nucleophilic ring-opening,affording a new synthetic route toward 1-naphthol derivatives.In the third part,the thiazolium salt-catalyzed domino reaction was developed.A new[3+2+1]cycloaddition reaction of arylglyoxals with acetylenedicarboxylates catalyzed by thiazolium salt in the presence of bases was conducted,paving the way to access structurally diverse 2-pyrones with good yields.During the reaction process,arylglyoxals played dual roles as a ring component as well as a carbonyl source.Thiazolium salt behaved as a carbene precursor,enabling the C-C bond breaking of the arylglyoxals,thereby providing a new method for the synthesis of 2-pyrones.In the fourth part,a new method for the synthesis of 3,3'-biindole derivatives was reported.Sc?OTf?₃-catalzyed nucleophilic substitution reaction between the preformed2-indolylmethanols and various indoles resulted in 3,3'-biindole derivatives with good yields.During the reaction process,Sc?OTf?₃ activated hydroxyl group of2-indolylmethanols to change its polarity and make its C3 nucleophilic center to be electrophilic center,which further coupled with indoles to generate the target products with high stereoselectivity.Furthermore,the dearomatization of indole ring of indolylmethanols was achieved.In this dissertation,three types of structurally diverse 1-naphthol,pyran,indole skeletons were constructed and 73 examples of new target compounds were efficiently synthesiszed with generally good yields.The structures of these resultant products were confirmed by NMR and IR,HRMS spectrometry,and some of them were further confirmed by single-crystal X-ray diffraction analysis.The reaction mechanisms were also proposed based some control experiments.