Synthesis Of Carbazolespirooxindoles Derivatives Via Asymmetric Diels-alder Reaction

The carbazolespirooxindoles structure is widely present in many natural products.Because of its excellent biological activity such as anti-cancer,it is widely used in the development and research of new structural drugs.The synthesis method,especially the synthesis method of chiral carbazolespirooxindoles structure,has attracted the attention of chemists,and many research results have been obtained.In this paper,chiral imidodiphosphoric acid is used as a catalyst,methyleneindolinones and 3-vinylindole are used as substrates to produce carbazolespirooxindoles derivatives through the asymmetric Diels-Alder reaction.The details are as follows:Firstly,we applied various chiral phosphoric acid and imidodiphosphoric acid catalysts to the asymmetric Diels-Alder reaction of 3-vinylindole and methyleneindolinones.Several attempts have been made to optimize the catalyst.Reaction temperature,solvent type and other various reaction conditions,so as to obtain the most suitable reaction conditions.Later,under the optimal conditions obtained,28 examples of reactions with different structures and substituents were expanded.It can be seen from the experimental results that the chiral imidodiphosphoric acid exhibits good catalytic ability,the yield can reach up to 98%,and the ee value can reach 98%.Then the imidodiphosphoric acid is applied to the asymmetric Diels-Alder reaction of 1'-aryl-3-vinylindole with methyleneindolinones.We tried several experiments to get the most suitable catalyst,and then through the exploration of the conditions of reaction temperature and solvent type,we found suitable experimental conditions.The yield can reach 85%,and the ee value can reach 82%.The experimental results show that the chiral imidodiphosphoric acid catalysts have excellent application effects in the synthesis of carbazolespirooxindoles derivatives by asymmetric Diels-Alder reaction,which opens up a direction for subsequent research.