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

It has been reported that hypervalent iodine reagents perform special reactivity in C-H activation catalyzed by palladium.By using the same hypervalent iodine reagent and substrat in two different reaction conditions,I respectively realized oxidation of allyl C-H and aromatization of allyl compounds in different reaction conditions;On the other hand,the direct esterification of aromatic C-H without directing groups has been completed through the use of hypervalent iodine reagents.The main contents are as follows:1.In the presence of the palladium catalysis,oxidation of allyl C-H with PhI?OPiv?2 as the oxidant and the source of ester was performed in ethylene glycol dimethyl ether,affording the esterifiable products in good yields?scheme 1?.The esterification of allyl C-H has been realized without another oxidants,compared to the general esterification,which improved the economy of reactions.The new compound was identified by ⁽13 C NMR and ¹H NMR.Scheme 12.Aromatization of allyl compounds with iodobenzene diacetate as the oxidant and the aromatic agent was performed in tetrahydrofuran in the presence of the palladium catalysis and Ag F additive,affording the aromatic products in mostly moderate to good yields?scheme 2?.The substrate range of this reaction are widely,and most of them have good yield.All new compounds were identified by ¹³C NMR and ¹H NMRScheme 23.Palladium catalyzed direct esterification of aromatic C-H was performed in benzene in the presence of pyridine ligands and Ph I?OCOPh?2,affording the esterifiable products in moderate yields?scheme 3?.The esterification reaction of the aromatic C-H was realized without using directing group.The stable and easily accessible hypervalent iodine reagents serves as both benzoxylate source and oxidant,which improved the economy of reactions.The new compound was identified by ¹³C NMR and ¹H NMR.Scheme 3.