Ring closing metathesis approach to produce precursors of nylon 11, 12, and 13 from oleic acid
Provided herein is a method of producing C11, C12, and C13 nylon precursors from oleic acid or esters of oleic acid, the method involving amide formation, ring-closing metathesis, and hydrogenation. Further provided are the products of the method described. Provided herein is a method for producing a lactam, the method comprising the steps of converting oleic acid or an ester of oleic acid into an amide having a general formula of H3C—(CH2)rCH═CH—(CH2)rCONR—(CH2)n-CH═CH2, wherein n is 1, 2, or 3, and R is either hydrogen or benzyl; subjecting the amide to a ring-closing metathesis reaction to produce an intermediate having a general formula of —(CH2)rCONR—(CH2) n-CH═CH2-, wherein n is 1, 2, or 3, R is either hydrogen or benzyl, and both ends are connected to each other; and hydrogenating the intermediate to produce a saturated lactam. In certain embodiments, the saturated lactam has a formula of —NH—(CH2) 10-CO—.
1. A method for producing a lactam, the method comprising:
converting oleic acid or an ester of oleic acid into an amide having a general formula of H 3 C—(CH 2 ) 7 —CH═CH—(CH 2 ) 7 —CONR—(CH 2 ) n —CH═CH 2 , wherein n is 1, 2, or 3, and R is either hydrogen or benzyl;
subjecting the amide to a ring-closing metathesis reaction to produce an intermediate having a general formula of —(CH 2 )— 7 —CONR—(CH 2 ) n —CH═CH 2 —, wherein n is 1, 2, or 3, R is either hydrogen or benzyl, and both ends are connected to each other; and
hydrogenating the intermediate to produce a saturated lactam.
2. The method of claim 1 , wherein the saturated lactam has a formula of —NH—(CH 2 ) 10 —CO—, —NH—(CH 2 ) 11 —CO—, or —NH—(CH 2 ) 12 —CO—.
3. The method of claim 1 , wherein the converting comprises subjecting the oleic acid or ester of oleic acid to an amide formation reaction with allyl amine, benzyl allyl amine, homoallyl amine, benzyl homoallyl amine, bishomoallyl amine, or benzyl bishomoallyl amine.
4. The method of claim 1 , wherein the amide has a formula of H 3 C—(CH 2 ) 7 —CH═CH—(CH 2 ) 7 —CONH—(CH 2 ) 2 —CH═CH 2 .
5. The method of claim 1 , wherein the amide has a formula of H 3 C—(CH 2 ) 7 —CH═CH—(CH 2 ) 7 —CONR—CH 2 —CH═CH 2 , wherein R is either hydrogen or benzyl.
6. The method of claim 1 , wherein the amide has a formula of H 3 C—(CH 2 ) 7 —CH═CH—(CH 2 ) 7 —CONH—(CH 2 ) 3 —CH═CH 2 .
7. The method of claim 1 , wherein the converting is conducted in an amidation solvent selected from the group consisting of: chlorobenzene, triethylamine, toluene, dichloroethane, chloropentafluorobenzene, octafluorotoluene, CH 2 Cl 2 , MeOH, pentane, hexane, heptane, EtOAc, i-ProOAc, dimethyl carbonate, diethyl carbonate, HOAc, DMSO, DMF, pyridine, anisole, water, Et 2 O, acetonitrile, hexafluorobenzene, and mixtures thereof.
8. The method of claim 1 , wherein the intermediate has a formula of —(CH 2 ) 7 —CONH—(CH 2 ) 2 —CH═CH 2 —.
9. The method of claim 1 , wherein the intermediate has a formula of —(CH 2 ) 7 —CONR—CH 2 —CH═CH 2 —, and R is either hydrogen or benzyl.
10. The method of claim 1 , wherein the intermediate has a formula of —(CH 2 ) 7 —CONR—(CH 2 ) 2 —CH═CH 2 —.
11. The method of claim 1 , wherein the ring-closing metathesis reaction is conducted in the presence of a metathesis catalyst.
12. The method of claim 11 , wherein the metathesis catalyst comprises a second generation Hoveyda-Grubbs catalyst, Stewart-Grubbs catalyst, or Umicore M74SiPr catalyst.
13. The method of claim 11 , wherein the metathesis catalyst is attached to a solid support, the metathesis catalyst being capable of repeated use.
14. The method of claim 11 , wherein at least one of the amide or the metathesis catalyst is dissolved in a metathesis solvent selected from the group consisting of: chlorobenzene, toluene, dichloroethane, chloropentafluorobenzene, octafluorotoluene, CH 2 Cl 2 , anisole, MeOH, pentane, hexane, heptane, EtOAc, i-PrOAc, dimethyl carbonate, diethyl carbonate, HOAc, DMSO, DMF, pyridine, water, Et 2 O, acetonitrile, hexafluorobenzene, and mixtures thereof.
15. The method of claim 1 , wherein the hydrogenation is conducted in the presence of a hydrogenation catalyst comprising a complex of Pd, Ru, or Ir.
16. The method of claim 15 , wherein the hydrogenation reaction comprises dissolving the intermediate and the hydrogenation catalyst in a polar or non-polar hydrogenation solvent selected from the group consisting of chlorobenzene, toluene, dichloroethane, chloropentafluorobenzene, octafluorotoluene, ethyl acetate, isopropyl acetate, hexane, heptane, diethyl ether, MTBE, methanol, ethanol, and isopropanol.
17. The method of claim 1 , wherein the hydrogenation is conducted at atmospheric pressure.
18. The method of claim 1 , wherein the hydrogenation is conducted in the presence of an acid additive selected from the group consisting of mineral acids and Lewis acids.
19. The method of claim 1 , wherein the oleic acid or ester of oleic acid is produced from storage lipids of algal biomass or from vegetable oil.