Boron Reagents Promoted Acylation Of Arenes And Application In Drug Synthesis

Friedel-Crafts acylation reactions are widely used in the synthesis of drug molecules and natural products.As the pressing needs in green chemistry,highly efficient,operational simple and atom-,step-economic Friedel-Crafts acylations are extremely important.Acylation at the C3 position of indoles usually needed pre-protection of N atom and using excess Lewis acids.In the first section of this thesis,we realized that acylation at the C3 position of free（N-H）indoles selectively using equivalent BEt₃to promote the reactions.Our study illuminated the scope and limitations of this acylation process with up to 91%yield.Using this mothod,we also achieved the hydrocarbylformylation and sulfonylation.Compared to conventional methods,this electrophilic reaction is highly atom and step-economic.Different functional groups were constructed via common N-B intermediate.The efficiency of the reaction was demonstrated in the synthesis of pravadoline andγ-carboline derivatives.In the second section,optimization of the reaction conditions for the key step for synthesis of cephalotaxine via Friedel-Crafts acylation was conducted based on our previous work,which using BF₃OEt₂as the Lewis acid.After sreening the types of anhydride,base,reaction temperature,we could obtain the product in 92%yield on large scale through simple workup.