Table 2. PhCH₃ Oxidation Depending on Initial Reaction Mixture Composition and Nature of Oxidant.

	VO(acac)2	Co(acac)2	OxalH	NHPI		selectivity (mol %)			TON
entry	×103 (M)				ΔPhCH3%	PhC(O)H	PhCH2OH	peroxidesd	by cation	by NHPI	ΔH2O2b (%)	EffH2O2c (%)
H2O2-Piloted Oxidationa
1	0.06		15		1.6	86	14	u/d	350	-	37	4
2	0.06		15	6	1.3	89	11	u/d	300	3	30	4
3	0.3		15		2.0	86	14	u/d	93	-	50	4
4	0.3			6	<0.1	trace	0	0	<1	<1	10	0
5		0.3		6	<0.1	trace	0	0	<1	<1	8	0
O2-Piloted Oxidatione
6	0.3			6	5.0	94	6	0	233	12
7	0.3		15	6	2.3	94	6	0	110	5.5
8		0.3		6	10.7	90	10	0	500	25
9	0.15	0.15		6	9.0	89	11	0	420	21
10	0.075	0.075		6	10.4	92	8	0	973	24
11	0.037	0.037		6	10.0	90	10	0	1867	23
12	0.020	0.020		6	6.7	93	7	0	1247	15
13		0.037		6	1.1	99	1	0	432	3
14		0.075		6	11.0	92	8	0	2053	26
15f	0.3			6	2.4	91	9	u/d	11	5	100

^a[PhCH₃]₀ = [H₂O₂]₀ = 1.4 M; 40 °C, 1 atm, MeCN, 5 h.

^bAmount of H₂O₂ consumed.

^cEff_H2O2 is the ratio of stoichiometric (due to the product yield) amount of H₂O₂ divided by the H₂O₂ consumed.

^dPeroxides content was tracked by treating the samples with Ph₃P (see the Experiments section). u/d—content undetected.

^e[PhCH₃]₀ (1.4 M), O₂ bubbling (100 mL min^–1), total reaction volume = 50 mL, 100 °C, 10 atm, 5 h, MeCN, stainless steel reactor. ΔPhCH₃ (substrate conversion) corresponds to the product yield due to almost 100% process selectivity.

^f[PhCH₃]₀ = 1.4 M, [H₂O₂]₀ = 0.14 M. Only traces of products were detected when OxalH was presented in Co(acac)₂-catalyzed oxidation by O₂ (100 °C, 10 atm). No products formed in a detectable amount in the absence of neither OxalH nor NHPI regardless of the catalyst and oxidant used. The combination of either VO(acac)₂ or Co(acac)₂ with NHPI in oxidation by H₂O₂ eliminates the advantages of the latter mediator developed in O₂-driven processes (run 14).