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. 2020 Dec 10;10(72):43962–43974. doi: 10.1039/d0ra08344e

Optimization of the catalytic oxidation of benzyl alcohol and reduction of nitrobenzene using 10 and 11, respectively.

Entry Solvent C–C Suzuki couplinga C–N couplingb
T (°C) Cat. 11 (mg) Yield (%) T (°C) NaBH4 (mmol) Cat. 11 (mg) Yield (%)
1 EtOH Ref. 1.0 55 Ref. 2.0 2.0 50
2 MeOH Ref. 1.0 60 Ref. 2.0 2.0 50
3 THF Ref. 1.0 N.R. Ref. 2.0 2.0 N.R.
4 CH3CN Ref. 1.0 55 Ref. 2.0 2.0 40
5 DMF Ref. 1.0 80 Ref. 2.0 2.0 88
6 Glycerol 120 1.0 84 160 2.0 2.0 85
7 Dioxane Ref. 1.0 30 Ref. 2.0 2.0 45
8 Toluene Ref. 1.0 55 Ref. 2.0 2.0 60
9 H2O Ref. 1.0 45 Ref. 2.0 2.0 30
10 DMSO Ref. 1.0 80 Ref. 2.0 2.0 90
11 DMSO 2 120 1.0 84 120 c 2.0 2.0 90 d
12 DMSO2 80 1.0 44 80 2.0 2.0 60
13 DMSO2 160 1.0 85 160 2.0 2.0 90
14 DMSO2 R.T. 1.0 N.R. Ref. 1.0 2.0 33
15 DMSO2 Ref. 0.001 50 Ref. 1.5 2.0 55
16 DMSO2 Ref. 0.05 68 Ref. 2.0 0.5 65
17 DMSO2 Ref. 1.5 80 Ref. 2.0 1.0 80
18 DMSO2 Ref. 2.0 84 Ref. 2.0 2.5 90
19e DMSO2 120 1.0 30 120 0 2.0 N.R.
a

Reaction conditions: benzyl alcohol (1.0 mmol), catalyst 11, temperature, solvent (2.0 mL, DMSO2: 3.36 g), O2 balloon (∼1.0 atm). For a better comparison, a constant time of 33 h was reported for all entries.

b

Reaction conditions: nitrobenzene (1.0 mmol), NaBH4 (2.0 mmol), catalyst 11, solvent (2.0 mL, DMSO2: 3.36 g). For the better comparison, a constant time of 4.2 h was reported for all entries.

c

No improvement was observed until 40 h.

d

No improvement was observed until 8 h.

e

The reaction was performed under air conditions.