Table 2. Ligand effect on C(sp²)–H hydroxylation ^{a , b} .

^aReaction conditions: 1a (0.1 mmol), Cu(OAc)₂ (0.2 mmol), CuBr (0.08 mmol), CsOAc (0.2 mmol), ligand (0.1 mmol), DMSO (1.0 mL), 100 °C, air, 6 h.

^bYield determined by ¹H NMR analysis of crude reaction mixture using CH₂Br₂ as an internal standard.