Palladium-catalyzed Decarboxylative Ortho-acylation Of Anilines With Carbamate As A Removable Directing Group

Over the past decades,transition-metal-catalyzed direct C-H functionalization with high atom economy has been significantly developed as one of the most powerful and straightforward strategies to construct complex target molecules from relatively simple materials.Among them,functional group-directed C-H activation protocols are particularly useful,and can achieve the formation of carbon-carbon,carbon-nitrogen,carbon-oxygen,carbon-sulfur and carbon-halogen bonds.Owing to regioselective functionalizations of ubiquitous C-H bonds in organic molecules at the desired positions.Synthetic utilities were significantly improved when these directing groups(DGs)could be remove or modify after the desired transformations.New methods have been developed to exploit a variety of removable DGs in recent years,thereby making these methods more useful in organic synthesis.In this thesis,we have demonstrated the Pd-catalyzed decarboxylative acylation of sp2 C-H bonds with aniline carbamates as the directing group.When using Pd(OAc)2 as the catalyst,(NH4)2S2O8 as the oxidant,1,2-dichloroethane as the solvent,aniline carbamates can react with a-oxocarboxylic acids to to afford diverse acylation products of aniline derivatives in moderate to good yields under mild conditions.This transformation exhibits broad substrate scope and highly functional group tolerance.In addition,the employed directing group can be easily removed to give the corresponding 2-amino aromatic ketones.Importantly,several transformations of the synthesized ortho-acylated anilines into several synthetically valuable products have been demonstrated for their utilities.