Direct Oxidative C–H Arylation of Benzoxazoles with Arylsulfonyl Hydrazides Promoted by Palladium Complexes
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Abstract This study describes a direct oxidative C-2 arylation of benzoxazoles using arylsulfonyl hydrazides as the aryl sources. A simple catalyst system [Pd(OAc)2 and Ph3P] allows the reactions to proceed smoothly under oxidative reaction conditions. Other heteroarenes such as caffeine and benzothiazole are also applicable substrates. Notably, this catalytic system tolerates halogen substituents which provides a useful complement to the current cross-coupling reactions which use aryl halides.
[1] L. Ackermann. Modern arylation methods , 2009 .
[2] J. Warner,et al. ORGANIC PREPARATIONS AND PROCEDURES INTERNATIONAL The New Journal for Organic Synthesis , 2008 .
[3] C. Bolm,et al. Transition metals for organic synthesis : building blocks and fine chemicals , 1998 .
[4] J. Tsuji,et al. Palladium Reagents and Catalysts , 1995 .