Palladium Catalyzed Esterification Of C-H Bond Using Hypervalent Iodine Reagents

There are two parts in this article,we have reported that hypervalent iodine reagents perform special reactivity in C-H benzoxylation catalyzed by palladium.C-H benzoxylation can be achieved through using hypervalent iodine reagents as both benzoxylate source and oxidant:1.A palladium-catalyzed ortho-C-H-benzoxylation of 2-arylpyridines using iodobenzene dibenzoates has been developed(Scheme 1).The reaction employed hypervalent iodine reagents as both benzoxylate source and oxidant which made the protocol simple and facile.It showed high regioselectivity and good functional group tolerance,and gave the mono-substituted products in moderate to excellent yields.It provides a simple and facile synthetically strategy for the construction of benzoic ester functionalities.2.A palladium-catalyzed non-directed C-H benzoxylation of simple arenes with iodobenzene dibenzoates as both benzoxylate source and oxidant has been developed(Scheme 2).Pyridine ligand-assisting strategy was used which greatly promoted the reactivity.Good functional group tolerance was shown in arene substrates as well as iodobenzene dibenzoates.It would provide a new methodology for synthesis of aryl benzoates through simple aromatic compounds.