To further promote the widely practical application of C−H activation, developing green and mild reaction conditions has invariably been the objective of researchers, especially when it comes to remote C−H activation reactions. Herein, we report a new cheap and powerful (n-Bu) 4 NNO 3 oxidant. This oxidant is efficient and universal for Pd(II)catalyzed sp 2 and sp 3 C−H olefination and allows the reaction to be carried out at room temperature. Because of this, we attempted to make C−H functionalization more economical and environmentally benign.

The silica gel promoted straightforward remote para‐C−H hydroxylation of aryl‐urea derivatives under metal‐free mild conditions by using diacetoxyiodobenzene as oxidant has been developed. Replacing the Lewis acids with silica gel effectively improved the tolerance of functional groups and resulted in a wide range of target compounds with various substituents in moderate to excellent yields. Moreover, this transformation has been demonstrated that could more effectively and conveniently synthesize pharmaceutical and biomedical compounds which contain 4‐hydroxyarlyurea skeleton.

Herein, we reported air stable, earth-abundant cobalt (III)-catalyzed regio-selective mono-olefination of arenes directed by urea under mild conditions through cross-dehydrogenative coupling( CDC) process . Under the optimized conditions, the high...