Table 1.

Selected Optimization for Amine-Catalyzed Remote C–H Hydroxylation^a

^aUnless otherwise noted, reactions were conducted on 0.2 mmol scale of 2a at 50 °C, using amounts of reagents shown and 2 mL of HFIP. Yields and selectivities determined by gas chromatography, with the exceptions of entries 1 and 5, which are based on isolated yields of products and 2a. Entry 1 performed on 1 mmol scale of 2a; isolated yield reported. Entry 2 data is from reference 8.

^bEntry 3 data is from reference 15a. Hydroxylation of 2a in reference 15a was calculated as 56% based on the limiting reagent (H₂O_2, 0.5 equiv). To compare more accurately with substrate-limited methods, we have recalculated the yield based on 2a he as the limiting reagent.

^cFor entries employing 1 equivalent of amine salt, 3 equiv of urea•H₂O₂ and 5 equiv of NaHCO₃ were used.

^dFor entries 11–14, experiments were performed using 1 equiv of pyrrolidine•HOTf, 3 equiv of urea•H₂O₂, and 5 equiv of NaHCO₃. See Supporting Information for additional details.