Delivering 2-Aryl Benzoxazoles through Metal-Free and Redox-Neutral De-CF3 Process.
Xinxin QiaoYong-De ZhaoMingru RaoZhan-Wei BuGuangwu ZhangHeng-Ying XiongPublished in: The Journal of organic chemistry (2021)
An unexpected cleavage of the Csp3-CF3 bond of CF3-hydrobenzoxazoles has been disclosed, affording a range of 2-aryl benzoxazoles under metal-free and redox-neutral conditions. This transformation has demonstrated broad substrate scope and good compatibility of functional groups. 2-Aryl benzothiazole and 2-aryl benzoimidazole could be smoothly assembled in the same manner. On the basis of preliminary mechanistic studies, base initiated and aromatization driven β-carbon elimination was considered to be the key step for the formation of 2. This reaction offers an alternative, facile, and sustainable route to access important 2-aryl benzoxazole motifs.