Methods of producing para-xylene and terephthalic acid

1. A method for producing para-xylene, comprising:

combining 2,5-dimethylfuran with ethylene and a catalyst to form a reaction mixture, wherein the catalyst comprises a metal cation and a triflate counterion, and wherein the metal cation is a Group 3 metal cation, a Group 9 metal cation, a Group 10 metal cation, a Group 11 metal cation, or a lanthanide series metal cation; and

producing para-xylene from at least a portion of the 2,5-dimethylfuran and at least a portion of the ethylene in the reaction mixture.

2. The method of claim 1 , further comprising isolating the para-xylene from the reaction mixture.

3. The method of claim 1 , wherein the 2,5-dimethylfuran, the ethylene, and the catalyst are further combined with a solvent to form the reaction mixture.

4. The method of claim 3 , wherein the solvent has a dipole moment above 0.1.

5. The method of claim 3 , wherein the solvent comprises an ether.

6. The method of claim 3 , wherein the solvent comprises dioxane, glyme, diglyme, triglyme, tetraglyme, or tetrahydrofuran, or any mixtures thereof.

7. The method of claim 6 , wherein the solvent comprises 1,4-dioxane.

8. The method of claim 1 , wherein the metal cation is a divalent metal cation or a trivalent metal cation.

9. The method of claim 8 , wherein the divalent metal cation is selected from the group consisting of Zn 2+ , Cu 2+ , Ni 2+ , and Co 2+ .

10. The method of claim 8 , wherein the trivalent metal cation is selected from the group consisting of Al 3+ , In 3+ , Fe 3+ , La 3+ , Gd 3+ , and Y 3+ .

11. The method of claim 1 , wherein the metal cation is silver, lead, or scandium.

12. The method of claim 1 , wherein less than 10% of the reaction mixture is 2,5-hexanedione.

13. The method of claim 1 , wherein at least a portion of the 2,5-dimethylfuran is converted to para-xylene at a temperature of at least 150° C.

14. The method of claim 13 , wherein at least a portion of the 2,5-dimethylfuran is converted to para-xylene at a temperature of between 150° C. and 300° C.

15. The method of claim 1 , further comprising adding one or more molecular sieves to the reaction mixture.

16. The method of claim 15 , wherein the one or more molecular sieves has a pore size of 3 Å to 100 Å.

17. The method of claim 3 , wherein the solvent comprises a C 1 to C 10 aliphatic solvent, a C 6 to C 12 aromatic solvent, or any combinations thereof.

18. The method of claim 3 , wherein the solvent comprises a C 6 -C 12 aromatic solvent.

19. The method of claim 18 , wherein the solvent comprises toluene.

20. The method of claim 1 , wherein the catalyst is a water-stable acid catalyst.

21. The method of claim 1 , wherein the metal cation is a Group 3 metal cation.

22. The method of claim 1 , wherein the metal cation is a Group 11 metal cation.

23. The method of claim 1 , wherein the metal cation is a lanthanide series metal cation.

24. A method for producing terephthalic acid, comprising:

a) producing para-xylene according to the method of claim 1 ; and

b) oxidizing the para-xylene to produce terephthalic acid.

25. A method for producing a compound of formula I, wherein formula I has the structure:

wherein each R 1 and R 2 is independently hydrogen or alkyl, wherein the method comprises:

combining a compound of formula II with ethylene and a catalyst to form a reaction mixture,

wherein the compound of formula II is:

wherein R 1 and R 2 are as defined for formula I above, and

wherein the catalyst comprises a metal cation and a triflate counterion, and wherein the metal cation is a Group 3 metal cation, a Group 9 metal cation, a Group 10 metal cation, a Group 11 metal cation, or a lanthanide series metal cation; and

producing a compound of formula I from at least a portion of the compound of formula II and at least a portion of the ethylene in the reaction mixture.

26. The method of claim 25 , wherein R 1 and R 2 are each methyl.

27. The method of claim 25 , wherein R 1 is H and R 2 is methyl.

28. The method of claim 25 , wherein at least a portion of the 2,5-dimethylfuran is converted to para-xylene at a temperature of at least 150° C.

29. The method of claim 25 , further comprising adding one or more molecular sieves to the reaction mixture.

30. The method of claim 25 , wherein less than 10% of the reaction mixture is a compound of formula III, wherein formula III has the structure

31. The method of claim 25 , wherein the metal cation is silver, lead, or scandium.

32. The method of claim 25 , wherein the compound of formula II, the ethylene, and the catalyst are further combined with a solvent to form the reaction mixture.

33. The method of claim 32 , wherein the solvent comprises a C 6 -C 12 aromatic solvent.

34. The method of claim 33 , wherein the solvent comprises toluene.

35. The method of claim 25 , wherein the catalyst is a water-stable acid catalyst.

36. The method of claim 25 , wherein the metal cation is a Group 3 metal cation.

37. The method of claim 25 , wherein the metal cation is a Group 11 metal cation.

38. The method of claim 25 , wherein the metal cation is a lanthanide series metal cation.

39. The method of claim 32 , wherein the solvent has a dipole moment above 0.1.

40. The method of claim 32 , wherein the solvent comprises an ether.

41. The method of claim 32 , wherein the solvent comprises dioxane, tetrahydrofuran, triglyme, or sulfolane, or any combinations thereof.

42. The method of claim 41 , wherein the solvent comprises 1,4-dioxane.

43. The method of claim 3 , wherein the metal cation is a trivalent metal cation selected from the group consisting of Al 3+ , In 3+ , Fe 3+ , La 3+ , Gd 3+ , and Y 3+ .

44. The method of claim 3 , wherein the metal cation is silver, lead, or scandium.