[3,3]-Overman Rearrangement Tandem Cyclization And Its Application In Indole Alkaloid Synthesis

As an important component of alkaloid families,indole alkaloids have a wide variety of species,complex structures and generally have good biological activities.Because of the excellent biological activity,that the synthesis of indole alkaloids has attracted great interest from chemists.However,there are many problems in the synthesis of indole alkaloids,such as how to construct complex parallel structures and quarter carbon centers.In this paper,we briefly review the synthetic development of indole alkaloids in recent years,and then elaborate on how to construct the 6,5,5 ring skeleton structure and rearrangement reaction in alkaloid synthesis.According to the literature,we used tryptamine as the starting substrate,through the protection of the amino group,the reduction of the anthracene ring,and the oxidation of the monohydric group to obtain a 1-hydroxytryptamine compound.Our best conditions are using 1-hydroxytryptamine as a substrate,TMG as a catalyst,DCM as a solvent and some trichloroacetonitrile.Then a 6,5,5 ring skeleton structure and a quaternary carbon center were completed,at the same time,the synthesis of cyclosamine compounds was finished by a series of overman rearrangement and cyclization.Under these conditions,the substrates of 1-hydroxytryptamine were extended.Specifically,the amino groups with various types of substituent groups on the benzene rings.Based on the reaction we designed,some reactions were extended we obtained satisfactory yields.In this thesis,a 1-hydroxytryptamine compound was obtained by reduction and oxidation reaction with a simple tryptamine as a substrate,and then a 6,5,5 cyclochromamide was obtained by a series of series rearrangement and cyclization.The synthocyclic structure and a quaternary carbon center were completed and we finish the synthesis of cyclosamine compounds.Subsequent work continues to be carried out by other members in our group.