C-H Functionalisation with Electrophiles

Several nickel-based catalyst systems have been proven to catalyse C-H arylation of heteroarenes with aryl halides. For example, a combination of Ni(OAc)2 and bipy or dppf catalyses the C-H arylation of azoles including thiazoles, benzothiazoles, oxazoles, benzoxazoles, and benzimidazoles with aryl chlorides, bromides and iodides as well as aryl triflates in the presence of LiOtBu or Mg(OtBu)2. The Ni(OAc)2/dppf/LiOtBu system is more effective for aryl chloride or triflate electrophiles. Nickel-catalysed direct allq ny-lation of azoles with all yl bromides was also carried out. Ni(COD)2/l,2-bis(diphenylphosphino)benzene (dppbz) is an effective catalyst and LiOtBu is a suitable base for this transformation. In some cases, a catalytic amount of Cul additive promotes the coupling.  

DMSO (3.5 equiv) PivOH (0.2 equiv) Na2C03 (2 equiv) 

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