Compositions and methods for stereoregular ring expansion metathesis polymerization

1. A compound having a structure represented by a formula:

wherein each occurrence of R 1 is independently selected from H and C1-C6 alkyl, or two adjacent R 1 are linked to form a five- to eight-member cyclic group; and

wherein R 2 is selected from Ar 1 , C1-C22 alkyl, halo, C1-C22 haloalkyl, hydrogen, amino, alkoxy, ether, and (R 3 ) 3 —Si—; and

wherein L 1 is absent or selected from phosphine, amine, or five- or six-membered monocyclic groups containing 1 to 4 heteroatoms;

wherein Ar 1 is an aryl or heteroaryl, with the proviso that when R 2 is Ar 1 then Ar 1 is pyrrolyl, furanyl, thiophenyl, imidazolyl, pyrazolyl, oxazolyl, isoxazolyl, thiazolyl, pyridinyl, pyrazinyl, pyrimidinyl, pyridazinyl, triazinyl, benzofuranyl, isobenzofuranyl, indolyl, isoindolyl, benzothiophenyl, benzimidazolyl, purinyl, indazolyl, benzoxazolyl, benzisoxazolyl, benzothiazolyl, maphthalenyl, anthracenyl, quinolinyl, isoquinolinyl, quinoxalinyl, acridinyl, quinazolinyl, cinnolinyl, phthalazinyl, or naphthyl; and

wherein each occurrence of R 3 is independently selected C1-C22 alkyl, Ar 1 , —O—(C1-C22 alkyl), —O—Ar 1 , —N—(C1-C22) alkyl, or —N—Ar 1 ;

provided that R 2 is not (CH 3 ) 3 —Si—.

2. The compound of claim 1 , wherein the compound has a structure represented by a formula:

3. The compound of claim 1 , wherein each R 1 is independently selected from H, methyl, ethyl, propyl, butyl, pentyl, and hexyl.

4. The compound of claim 1 , wherein the compound has a structure represented by a formula:

5. The compound of claim 1 , wherein R 2 is selected from methyl, ethyl, propyl, butyl, pentyl, hexyl, and naphthyl.

6. The compound of claim 1 , wherein R 2 is Ar 1 .

7. The compound of claim 1 , wherein L 1 is absent or is an amine.

8. The compound of claim 1 , wherein L 1 is absent and R 2 is t-butyl.

9. The compound of claim 1 , wherein the compound has a structure represented by a formula:

10. A method for making a compound according to claim 1 , the method comprising providing a complex having a structure represented by a formula:

wherein each occurrence of R 1 is independently selected from H and C1-C6 alkyl; and

wherein each occurrence of L 1 is selected from phosphine, amine, or five- or six-membered monocyclic groups containing 1 to 4 heteroatoms or both L 1 together comprise a bidentate ligand;

and reacting with a terminal alkyne having a structure represented by a formula:

wherein R 2 is selected from Ar 1 , C1-C22 alkyl, and (R 3 ) 3 —Si—;

wherein each occurrence of R 3 is independently selected from C1-C22 alkyl or Ar 1 ; and

wherein Ar 1 is an aryl or heteroaryl, with the proviso that when R 2 is Ar 1 then Ar 1 is pyrrolyl, furanyl, thiophenyl, imidazolyl, pyrazolyl, oxazolyl, isoxazolyl, thiazolyl, pyridinyl, Pyrazinyl, pyrimidinyl, pyridazinyl, triazinyl, benzofuranyl, isobenzofuranyl, indolyl, isoindolyl, benzothiophenyl, benzimidazolyl, purinyl, indazolyl, benzoxazolyl, benzisoxazolyl, benzothiazolyl, maphthalenyl, anthracenyl, quinolinol, isoquinolinyl, quinoxalinyl, acridinyl, quinazolinyl, cinnolinyl, phthalazinyl, or naphthyl;

provided that R 2 is not (CH 3 ) 3 —Si—;

thereby yielding a compound according to claim 1 .

11. The method of claim 10 , wherein the complex has a structure represented by a formula:

12. The method of claim 10 , wherein the complex has a structure represented by a formula:

13. A method for ring expansion metathesis polymerization comprising:

reacting a compound of claim 1 ; and

one or more cyclic alkenes to form an unsaturated cyclic polymer.

14. The method of claim 13 , wherein the cyclic alkene comprises one or more of cyclopropene, cyclobutene, cyclopentene, cycloheptene, cyclooctene, norbornene, dicyclopentadiene, norbornene anhydride, an ester of norbornene anhydride, an imide of norbornene anhydride, oxanorbornene, oxanorbornene anhydride, an ester of oxanorbornene anhydride, an imide of oxanorbornene anhydride, and substituted variations of the foregoing.

15. The method of claim 13 , wherein the cyclic alkene comprises a substituted cyclic alkene and the substitution is not a carboxyl, a carbonyl, an alcohol, or a thiol.

16. The method of claim 13 , wherein the cyclic alkene comprises a substituted cyclic alkene and the substitution comprises an alkyl group or an aryl group.

17. The method of claim 13 , wherein the compound has a structure represented by a formula:

18. The method of claim 13 further comprising hydrogenating the unsaturated cyclic polymer to provide a saturated stereoregular cyclic polymer.

19. The method of claim 18 , wherein the saturated stereoregular cyclic polymer has a structure:

wherein n is a positive integer.

20. The method of claim 18 , wherein n is in a range of 1 to 20,000.