Selective construction of fused heterocycles by mild oxidative C-H functionalization using nonmetallic catalysis

He Zhao,¹ Jialu Sun,¹ Rongqing Guan,¹ Qinghao Song,¹ Huanfeng Jiang,¹ Min Zhang^1,*

ABSTRACT: Under metal-free catalysis and external energy input-free conditions, there remain to date significant unmet challenges in precise C−H functionalization with controllable sites and numbers. Here, by establishing a low N-doped hierarchical porous graphitic carbon/hexafluoroisopropanol (HFIP) catalyst system, we demonstrate, for the first time, a direct construction of structurally novel π-extended N,O-heterocycles from tetrahydroquinoxalines and 2-naphthols via selective oxidative aryl C−H bifunctionalization at room temperature, proceeding with the striking features of good substrate and functional group compatibility, excellent step and atom-efficiency, and the use of easily accessible and reusable catalyst and naturally abundant oxidant. Mechanistic study reveals that the in situ formed catalyst-O₂ species stabilized by HFIP enables a decent oxidation of substrates to match the coupling processes. The work highlights the potential practicality of the strategy merging suitable carbon material and hexafluoroisopropanol in further development of oxidative C−H functionalization reactions under sustainable catalysis.

Cell Rep. Phy. Sci. 2021，Doi：org/10.1016/j.xcrp.2021.100383