Studies On The C-H Arylation And Acylation Of Azoles With Carboxylic Acids Through Pd/Cu Cooperative Catalysis

Biaryl heterocyclic compounds and biaryl ketone heterocyclic compounds are a class of important heterocyclic compounds,which widely occur in natural products,drug molecules and functional material molecules.Efficient synthesis of those compounds is of significance.Their traditional synthesis is highly dependent on the condensation/cyclization reaction,the C-H arylation and acylation of azoles with aryl halides,carboxylic acid derivatives.Carboxylic acids are cheap and readily available.They can used in organic synthesis as the aryl and acyl sources.In this paper,the C-H arylation and acylation of azoles and carboxylic acids are selectively achieved through Pd/Cu copperative catalysis.The details are as follows:(1)Pd/Cu cooperatively catalyzed decarbonylation C-H arylation of azoles with carboxylic acids: With the use of Pd/Cu as the catalyst and Boc2 O as the in situ activator of carboxylic acids,the decarbonylation C-H arylation of azoles is realized.This reaction does not require stoichiometric oxidant and directing groups.Wide substrate scope and high functional group tolerance are demonstrated.The pharmaceutical molecules can be directly modified by the strategy.This reaction provides a good method for preparing biaryl heterocyclic compounds.(2)Pd/Cu cooperatively catalyzed C-H acylation of azoles with carboxylic acids:By switching the ligand from dppp to dpph or Ph2 PCy,the C-H acylation forming biaryl ketone heterocyclic compounds is selectively achieved.The reaction conditions are facile and mild with a wide substrate scope for both azoles and carboxylic acids.This reaction can also be applied to the modification of bioactive compounds.