a Reaction conditions: cyclohexane (0.58 mmol,
50 mg, 1 equiv), NaCl, DIB, H2O, DCM. 18 W blue light,
air, rt. b Yields are based on cyclohexane and
detected by 1H NMR analysis using
CH2Br2 as an internal
standard.c Purple light instead of blue light.d In the dark. e DIB
(0.155 mmol, 1 equiv), 4 (0.67 mL, 40 equiv), air, rt. Yields
were based on DIB and detected by 1H NMR analysis
using CH2Br2 as an internal standard.
halogenation and oxidation could proceed smoothly (11a-11c and12a-12c ). Unlike halogenation, the substrate structure had
remarkable effects on the oxidation results. Saturated monocyclic
hydrocarbon and linear alkanes were oxidized to the corresponding
alcohol and ketone, without formation of overoxidized products.
Hydroxyketone 12c was generated as the single product via
α-oxidation of cyclic ketone, while substrates bearing one or more
tertiary carbons were exclusively transformed into corresponding
tertiary alcohols. It’s worth noting that a methyltied to aromatic ring
(e.g., toluene) was directly overoxidized into carboxylic acid in high
yield (85%), instead of alcohol or aldehyde.
Table 2 Activation of various C−H reagents with DIB