RESUMO
A copper-catalyzed direct ortho-Csp2-H thiocyanation of free anilines has been developed. This method employs stable and non-toxic ammonium thiocyanate as a thiocyanation source, and tert-butyl hydroperoxide as the oxidant, enabling the synthesis of ortho-thiocyanated anilines with good yields and broad substrate tolerance. Hitherto, no reports have been found in the literature for the ortho-thiocyanation of aromatic amines, making this reaction an important breakthrough in synthetic organic chemistry.
RESUMO
Heterocyclic compounds are widely present in the core structures of several natural products, pharmaceuticals and agrochemicals, and thus great efforts have been devoted to their synthesis in a mild and simpler way. In the past decade, remarkable progress has been made in the field of heterocycle synthesis by employing C-H functionalization as an emerging synthetic strategy. As a complement to previous protocols, transition metal catalyzed C-H functionalization of arenes using various directing groups has recently emerged as a powerful tool to create different classes of heterocycles. This review is mainly focussed on the recent key progress made in the field of the synthesis of N,O-heterocycles from olefins and allenes by using nitrogen based and oxidizing directing groups.