Production of fatty olefin derivatives via olefin metathesis
In one aspect, the invention provides a method for synthesizing a fatty olefin derivative. The method includes: a) contacting an olefin according to Formula I with a metathesis reaction partner according to Formula IIb in the presence of a metathesis catalyst under conditions sufficient to form a metathesis product according to Formula IIIb: and b) converting the metathesis product to the fatty olefin derivative. Each R 1 is independently selected from H, C 1-18 alkyl, and C 2-18 alkenyl; R 2b is C 1-8 alkyl; subscript y is an integer ranging from 0 to 17; and subscript z is an integer ranging from 0 to 17. In certain embodiments, the metathesis catalyst is a tungsten catalyst or a molybdenum catalyst. In various embodiments, the fatty olefin derivative is a pheromone. Pheromone compositions and methods of using them are also described.
1. A method for synthesizing a fatty olefin derivative, the method comprising:
a) contacting
a linear C 3 -C 12 olefin with a Δ 9 -unsaturated fatty acid alkyl ester in the presence of a Z-selective metathesis catalyst to form a
C 11 -C 20 (Z)-9-unsaturated fatty acid alkyl ester; and
b) converting the C 11 -C 20 (Z)-9-unsaturated fatty acid alkyl ester to the fatty olefin derivative;
wherein the fatty olefin derivative is selected from the group consisting of a C 11 -C 20 (Z)- 9 -fatty alcohol, an acetate ester of a C 11 -C 20 (Z)-9-fatty alcohol, and a C 11 -C 20 (Z)-9-alkenal.
2. The method of claim 1 , wherein
the linear C 3 -C 12 olefin is a linear C 3 -C 12 alpha olefin.
3. The method of claim 1 , wherein converting the metathesis product to the fatty olefin derivative comprises contacting the C 11 -C 20 (Z)-9-unsaturated fatty acid alkyl ester with a reducing agent under conditions sufficient to form the C 11 -C 20 (Z)-9-fatty alcohol.
4. The method of claim 3 , wherein the reducing agent is sodium bis(2-methoxyethoxy)aluminum hydride.
5. The method of claim 3 , wherein converting the metathesis product to the fatty olefin derivative further comprises contacting the C 11 -C 20 (Z)-9-fatty alcohol with an acylating agent in the presence of a base under conditions sufficient to form the acetate ester of the C 11 -C 20 (Z)-9-fatty alcohol.
6. The method of claim 5 , wherein the acylating agent is acetic anhydride.
7. The method of claim 3 , wherein converting the metathesis product to the fatty olefin derivative further comprises oxidizing the C 11 -C 20 (Z)-9-fatty alcohol to form the C 11 -C 20 (Z)-9-alkenal.
8. The method of claim 1 , wherein converting the metathesis product to the fatty olefin derivative comprises contacting the C 11 -C 20 (Z)-9-fatty acid alkyl ester with a reducing agent under conditions sufficient to form the C 11 -C 20 (Z)-9-alkenal.
9. The method of claim 8 , wherein the reducing agent is amine-modifed sodium bis(2-methoxyethoxy)aluminumhydride.
10. The method of claim 1 , wherein:
the fatty olefin derivative is (Z)-tetradec-9-en-l-yl acetate,
the linear C 3 -C 12 olefin is hex-1-ene,
and
the C 11 -C 20 (Z)-9-unsaturated fatty acid alkyl ester is a (Z)-9-tetradec-9-enoate alkyl ester; and
wherein converting the (Z)-9-tetradec-9-enoate alkyl ester to the (Z)-tetradec-9-en-1-yl acetate comprises:
contacting the (Z)-9-tetradec-9-enoate alkyl ester with a reducing agent to form (Z)-tetradec-9-en-1-ol, and
acylating the (Z)-tetradec-9-en-1-ol to form the (Z)-tetradec-9-en-1-yl acetate.
11. The method of claim 10 , wherein the Δ 9 -unsaturated fatty acid alkyl ester is methyl 9-decenoate and the (Z)-9-tetradec-9-enoate alkyl ester is methyl Z-9-tetradecenoate.
12. The method of claim 10 , wherein the reducing agent is sodium bis(2-methoxyethoxy)aluminumhydride.
13. The method of claim 10 , wherein acylating the (Z)-tetradec-9-en-1-ol comprises contacting the (Z)-tetradec-9-en-1-ol with an acylating agent in the presence of a base under conditions sufficient to form (Z)-tetradec-9-en-1-yl acetate.
14. The method of claim 13 , wherein the acylating agent is acetic anhydride.
15. The method of claim 1 , wherein:
the fatty olefin derivative is (Z)-tetradec-9-enal,
the linear C 3 -C 12 olefin is hex-1-ene,
and
the C 11 -C 20 (Z)-9-unsaturated fatty acid alkyl ester is a (Z)-9-tetradec-9-enoate alkyl ester; and
wherein converting the (Z)-9-tetradec-9-enoate alkyl ester to the fatty olefin derivative comprises contacting the (Z)-tetradec-9-enoate alkyl ester with a reducing agent to form the (Z)-tetradec-9-enal.
16. The method of claim 15 , wherein the reducing agent is amine-modified sodium bis(2-methoxyethoxy) aluminumhydride.
17. The method of claim 15 , wherein the Δ 9 -unsaturated fatty acid alkyl ester is methyl 9-decenoate and the C 11 -C 20 (Z)-9-unsaturated fatty acid alkyl ester is methyl Z-9-tetradecenoate.
18. The method of claim 1 , wherein:
the fatty olefin derivative is (Z)-tetradec-9-enal,
the linear C 3 -C 12 olefin is hex-1-ene,
and
the C 11 -C 20 (Z)-9-unsaturated fatty acid alkyl ester is a (Z)-9-tetradec-9-enoate alkyl ester; and
wherein converting the (Z) 9-tetradec-9-enoate alkyl ester to the (Z)-tetradec-9-enal comprises
contacting the (Z)-9-tetradec-9-enoate alkyl ester with a reducing agent to form (Z)-tetradec-9-en-1-ol, and
oxidizing the (Z)-tetradec-9-en-1-ol to form the (Z)-tetradec-9-enal.
19. The method of claim 18 , wherein the reducing agent is sodium bis(2-methoxyethoxy)aluminumhydride.
20. The method of claim 18 , wherein the Δ 9 -unsaturated fatty acid alkyl ester is methyl 9-decenoate and the metathesis product is methyl Z-9-tetradecenoate.
21. The method of claim 1 , wherein the metathesis catalyst has a structure according to Formula 2a:
wherein:
M is Mo or W;
R 3a is aryl, heteroaryl, alkyl, or cycloalkyl, each of which is optionally substituted;
R 7a is pyrrolyl, imidazolyl, indolyl, pyrazolyl, azaindolyl, or indazolyl, each of which is optionally substituted;
R 8a is optionally substituted aryl;
R 5a is a hydrogen atom, alkyl, or alkoxy;
R 4b is a hydrogen atom, —O—(C 1-6 alkyl), —CH 2 —O—(C 1-6 alkyl), heteroalkoxy, or —N(C 1-6 alkyl) 2 ;
R 4c and R 4d are independently a hydrogen atom, C 1-6 alkyl, C 1-6 alkoxy, a halogen atom, —NO 2 , an amide, or a sulfonamide.
22. The method of claim 1 , wherein the metathesis catalyst is selected from the group consisting of:
23. The method of claim 1 , wherein the catalyst is present in an amount less than 0.01 mol % with respect to the olefin or to the metathesis reaction partner.
24. The method of claim 1 , wherein at least about 80% of the metathesis product is a Z olefin.
25. The method of claim 1 , wherein at least about 90% of the metathesis product is a Z olefin.