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von Angerer, S., Science of Synthesis, (2005) 26, 75.
A number of diverse cobalt complexes can be used as catalysts for the oxidation of secondary alcohols to ketones with molecular oxygen. The cobalt(II) or cobalt(III) compounds applied are of variable complexity.[244–251] When cobalt(II) acetate or tris(acetylacetonato)cobalt(III) complex are used N-hydroxyphthalimide has to be added as a cooxidant to obtain aliphatic and alicyclic ketones in good yields (Table 5, entries 1–3).[244,245] With these reagents cyclic 1,3- and 1,4-diols are converted into the corresponding hydroxy ketones whereas cyclic 1,2-diols react to form mixtures of 1,2-diones and dicarboxylic acids. For the aerobic oxidation of alcohols, cobalt(II) Schiff base complexes, such as 90 and 91 (Scheme 57) can also be used as the catalyst either alone[252] or in the presence of aldehyde cofactors (entries 5 and 6).[247,248] Typical examples for the use of cobalt compounds, including bis(1,1,1-trifluoroacetylacetonato)cobalt(II) (92) (Table 5, entry 7), in the preparation of ketones 93 are listed in Table 5.
Meeeee 88 Meeeee-Meeee Meeeeeeee eee eee Meeeeeeee ee Meeeeeee eeee Meeeeeeee Meeeee[888-888,888]
Meeee 8 Meeeeeeee ee Meeeeeee ee Meeeeee eeee Meeeeeeee Meeeee ee eee Meeeeeee ee Meeeee-Meeee Meeeeeeee[888–888]
| Meeee | Meeeee 88 | Meeeeeee | Meeeeeeeee | Meeee (%) | Mee |
|---|---|---|---|---|---|
| 8 | eeeee-8-eee | Me(MMe)8 (8.8 eee%), M-eeeeeeeeeeeeeeeeee (88 eee%), MMMMe (8 eee%) | MeMMe, ee, 88 e | 88 | [888] |
| 8 | 8-eeeeeeeeeeee-eeeeeeee | Me(eeee)8 (8 eee%), M-eeeeeeeeeeeeeeeeee (88 eee%) | MeMM, ee, 8 e | 88 | [888] |
| 8 | 8-eeeeeeeeeee-eeeeeeee | Me(eeee)8 (8.8 eee%), M-eeeeeeeeeeeeeeeeee (88 eee%) | MeMM, 88°M, 88 e | 88 | [888] |
| 8 | eeeeeeeee-8-eee | Me(MMe)8 (8.8 eee%), M-eeeeeeeeeeeeeeee (88 eee%), MeMM8M (8 eee%) | MeMMe, 888°M, 8 e | 88 | [888] |
| 8 | 8-eeeeeeeeeeeeee-8-eeeeeeeeeeeeeeeeeee | 88 (8 eee%), eeeeeeeeee (8 eeeee) | MeMM, 8-Å eeeeeeeee eeeeee, ee, 88–88 e | 88 | [888] |
| 8 | eeeeeeeeeeeeeee | 88 (8 eee%), eeeeeeeeeee (8 eeeee) | MeMM, Me8MM8, ee, 88 e | 88 | [888] |
| 8 | eeeee-8-eee | 88 (88 eee%) | eeeeeee, 8-Å eeeeeeeee eeeeee, 88°M, 88 e | 88 | [888] |
e MMMM = 8-eeeeeeeeeeeee eeee.
Meeeeeeeeeee Meeeeeeee
Meeeeeeee ee Meeeeeee ee Meeeeee 88: Meeeeeeee ee Meeee-8-eee (Meeee 8, Meeee 8); Meeeeee Meeeeeeee:[888]
Me MeMMe (8 eM) eeee ee eeeee-8-ee (8 eeee), M-eeeeeeeeeeeeeeeeee (88 ee, 8.8 eeee), Me(MMe)8 (8.8 ee, 8.888 eeee), eee 8-eeeeeeeeeeeee eeee (88 ee, 8.88 eeee) eee eeeeee ee e eeeee-eeeeee eeeee eeeeeeee eeee e eeeeeee eeeeee eeee M8. Mee eeeeeee eee eeeeeee ee 88°M eee 88 e. Meeeeee ee eee eeeeeee eeeee eeeeeee eeeeeeee eeee e eeeeee, eeeee eee eeeeeeee ee eeeeee eeeeeeeeeeeeee (eeeeee eee, eeeeee/MeMMe 8:8) ee eeee eee eeeeeee; eeeee: 88%.
References
| [244] | Meeeeee, M.; Meeeeee, M.; Meeeeee, M.; Meeeeeeee, M.; Meeee, M., M. Mee. Meee., (8888) 88, 8888. |
| [245] | Meeeeee, M.; Meeeeeeee, M.; Meeeeeeee, M.; Meeee, M., Meeeeeeeeee Meee., (8888) 88, 8888. |
| [246] | Meeeeeeee, M.; Meeeeeee, M.; Meeeee, M. M. M. M.; Meeeeee, M.; Meeeeee, M. M., Mee. Meeee. Meeee., (8888) 888, 888. |
| [247] | Meeee, M. M. M.; Meeeeeeeeeeee, M.; Meeee, M., Meeeeeeeeee Meee., (8888) 88, 8888. |
| [248] | Meeeeeeee, M.; Meeee, M. M.; Meeeeee, M. M.; Meee, M.; Meeeee, M.; Meeeeeeeeeee, M.; Meeeeeee, M., Mee. M. Mee. Meee., (8888), 8888. |
| [249] | Meeeee, M.; Meeeeeeee, M., Meee. Meee., (8888), 888. |
| [250] | Meeeee, M. M.; Meee, M. M.; Meee, M., Meeeeeeeeee Meee., (8888) 88, 888. |
| [251] | Meee, M. M.; Meee, M., M. Mee. Meeee. M: Meee., (8888) 888, 888. |
| [252] | Meeeee, M. M.; Meee, M. M.; Meee, M., M. Mee. Meeee. M: Meee., (8888) 888, 88. |
Meeeeee Meeeeeeeeee
- 8.Meeeee-Meee, (8888) 88/8e, 888.
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