Direct Arylation by C-H Functionalisation

During the current decade, reactions based on direct C-H functionalisation, and in particular Pd-catalysed direct arylation, have witnessed extraordinary progress. The use of NHC-Pd catalysts (especially well-defined complexes) in these transformations is much less documented than ligandless systems or those using commercially available phosphines in situ. 

Sanford later reported the direct arylation of A-methylindole with hyper-valent iodine reagents using the simple Pd complex [(IMes)Pd(OAc)2l]. 

Finally, Greaney recently reported the use of PEPPSI-IPr in the direct arylation of oxazoles, although the scope of this reaction was limited.  

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