Mild and selective vanadium-catalyzed oxidation of benzylic, allylic, and propargylic alcohols using air
View Patent ↗The invention concerns processes for oxidizing an alcohol to produce a carbonyl compound. The processes comprise contacting the alcohol with (i) a gaseous mixture comprising oxygen; and (ii) an amine compound in the presence of a catalyst, having the formula: where each of R 1 -R 12 are independently H, alkyl, aryl, CF 3 , halogen, OR 13 , SO 3 R 14 , C(O)R 15 , CONR 16 R 17 or CO 2 R 18 ; each of R 13 -R 18 is independently alkyl or aryl; and Z is alkl or aryl.
1. A process for oxidizing an alcohol to produce a carbonyl compound, said process comprising contacting the alcohol with
(i) a gaseous mixture comprising oxygen; and
(ii) an amine compound;
said contacting occurring in the presence of a catalyst, said catalyst comprising two nitrogen-containing heterocycles complexed with vanadium and having the formula:
wherein:
each of R 1 -R 12 are independently H, alkyl, aryl, CF 3 , halogen, OR 13 , SO 3 R 14 , C(O)R 15 , CONR 16 R 17 or CO 2 R 18 ;
each of R 13 -R 18 is independently alkyl or aryl; and
Z is alkl or aryl.
2. The method of claim 1 , wherein Z is alkyl.
3. The method of claim 1 , wherein Z is isopropyl.
4. The method of claim 1 , wherein said amine is a trialkyl amine.
5. The method of claim 1 , wherein said amine is triethylamine.
6. The method of claim 1 , wherein each of R 1 -R 12 is H, alkyl or aryl.
7. The method of claim 1 , wherein each of R 1 -R 12 is H.
8. The method of claim 7 , wherein Z is isopropyl.
9. The method of claim 8 , wherein said amine is triethylamine, diisopropylethylamine, 1,4-diazabicyclo[2.2.2]octane, or 2,2,6,6-tetramethylpiperidine-1-oxyl.
10. The method of claim 8 , wherein said amine is triethylamine.
11. The method of claim 1 , wherein said alcohol is of the formula
wherein R 19 is selected from aryl, vinyl, and alkynyl, and wherein R 20 is selected from H, methyl, and aryl.
12. The method of claim 9 , wherein said alcohol is of the formula
wherein R 19 is selected from aryl, vinyl, and alkynyl, and wherein R 20 is selected from H, methyl, and aryl.
13. The method of claim 1 , wherein said contacting occurs in the presence of a solvent selected from one or more of water, 1,2-dichloroethane, ethylacetate, toluene, tetrahydrofuran, acetonitrile, dichloromethane, 1,2-dichlorobenzene and 2-methyl-tetrahydrofuran.
14. The method of claim 1 , wherein said alcohol is a benzylic alcohol, allylic alcohol, or propargylic alcohol.
15. The method of claim 1 , wherein said contacting occurs at a temperature in the range of from 25° C. to 150° C.
16. The method of claim 15 , wherein said catalyst is of the formula
17. The method of claim 1 , wherein said gaseous mixture is air.