Boron Catalytic Asymmetric Friedel-Crafts Alylation Reaction And Its Application Research

Chemists Charles Friedel and James crafts jointly invented the Friedel-Crafts reaction,which provided great help for the subsequent organic chemical synthesis.Asymmetric Friedel-Crafts reaction of indole with chiral N-tert-butylsulphonimides α(3-indolyl)glycine and its derivatives are the most direct and convenient reagent availability method,which can efficiently synthesize highly enantiomerically enrichedα-The methods of(3-indolyl)glycine and its derivatives still face many problems,such as the use of large catalyst equivalent,the use of unprotected indole substrate,the control of stereoselectivity and many reaction by-products.In this paper,a new nonmetallic catalytic asymmetric Friedel-Crafts reaction is developed at the C-3 position of indole and the C-2 position of pyrrole.This paper found a higher performance,environment friendly trifluorophenyl borane(B(C6F5)3)catalyst for catalytic indole/pyrrole and imide asymmetric Friedel-Crafts alkylation reaction.Under the catalysis of B(C6F5)3,indoles and catalysts with different solvents,temperatures and equivalents were tested to make indoles react with imines,and the optimum conditions were selected.Under the optimum conditions,the universality of different indole substituents and the universality of the indole electron-withdrawing substituents and the indole electron-donating substituents were investigated.At the same time,the universality of different substituted imines to the reaction was also investigated.On the basis of this study,the universality of different substituted pyrrole and the universality of the reaction between different substituted imines and pyrrole were investigated.The experimental results show that the newly developed asymmetric FriedelCrafts alkylation reaction is feasible with simple reaction conditions,high yield and good selectivity(dr>25:1).The developed asymmetric Friedel-Crafts reaction is expected to play an important role in organic synthesis and medicine.Important intermediates were obtained through Friedel-Crafts alkylation reaction and further reaction,which provided a reference for the future experimental study of organic synthesis.