# US 9,040,653 B2 · Ring-opening polymerization of cyclic compounds catalyzed by carbene derivatives

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- Number: US 9,040,653 B2
- Document ID: US9040653B2
- Status: Granted
- Kind: B2
- Application number: 13/034,620
- Filed: 2011-02-24
- Published: 2011-06-16
- Granted: 2015-05-26
- Earliest claimed: 2008-09-01
- Assignees: Nanjing University of Technology
- Applicants: Zhenjiang Li; Pingkai Ouyang; He Huang
- Inventors: Zhenjiang Li; Pingkai Ouyang; He Huang
- Web page: https://patentgrep.com/patent/US9040653B2

## CPC

- C08G 63/08: Lactones or lactides
- B01J 31/40: Regeneration or reactivation
- C08G 63/785: {characterised by the apparatus used}
- C08G 63/823: {for the preparation of polylactones or polylactides}
- C08G 65/2609: {containing aliphatic hydroxyl groups}
- C08G 65/2672: {Nitrogen or compounds thereof}
- C08G 69/20: characterised by the catalysts used
- C08G 77/08: characterised by the catalysts used
- B01J 31/04: containing carboxylic acids or their salts {(B01J31/0277 - B01J31/0298 take precedence; multi-metal carboxylate complexes like Pd (II) acetate, i.e. Pd3 (OAc) 6 or Cr(II)acetate, i.e. Cr2(OAc)4 B01J31/2226)}
- C08G: MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS

## Abstract

This disclosure provides methods of controlled polymerization of cyclic compounds catalyzed by carbene derivatives having a general formula as shown below, and to obtain a biodegradable polymeric material having a large molecular weight, a narrow dispersity, and no metallic impurity.

## Claims

### Claim 1

A method for ring-opening polymerization of cyclic compounds, comprising:
providing a cyclic compound, wherein the cyclic compound is a macrocyclic oligomer, wherein the macrocyclic oligomer is obtained by prepolymerization of one or more cyclic monomers chosen from:
wherein A is [—(CR5R6)—]n, in which n is an integer from 2 to 10; R5 and R6 are independently chosen from H, alkyl groups with 1 to 5 carbon atoms, and alkyl groups having 1 to 5 carbon atoms with substituents chosen from halogens or a hydroxyl group; and X is chosen from O and N;
polymerizing a reaction mixture comprising the macrocyclic oligomer, an alcohol initiator, and a carbon dioxide adduct of carbene, wherein the reaction mixture is solvent-free,
wherein the carbon dioxide adduct of carbene has a structure represented by formula (I)
wherein the dotted line together with the solid line parallel to the dotted line represents a single bond or a double bond;
X1 is chosen from S and N;
X2 is chosen from C and N;
R1, R2, R3, and R4 satisfy at least one of the following conditions:
(I) R1 and R2 are independently chosen from
hydrogen,
alkyl groups having 1 to 10 carbon atoms,
alkyl groups having 1 to 10 carbon atoms and one or more substituents chosen from halogens, a hydroxyl group, a phenyl group, and a cyano group,
cycloalkyl groups having 3 to 6 carbon atoms,
a halogen atom,
an adamantane group,
a phenyl group, and
a substituted phenyl group;
(II) R3 and R4 are independently chosen from
hydrogen,
a halogen atom,
a cyano group,
a hydroxyl group,
alkyl groups having 1 to 4 carbon atoms,
alkyl groups having 1 to 4 carbon atoms and one or more substituents chosen from halogens, a hydroxyl group, a phenyl group, and a cyano group,
a phenyl group, and
a substituted phenyl group;
(III) R3 and R4 are connected to form cycloalkyl or cycloalkenyl rings having 3 to 8 carbon atoms fused to the five-membered ring that contains X1, X2, and the nitrogen atom (in which case X2 and the carbon atom in the 5-membered ring next to X2 are also part of said cycloalkyl or cycloalkenyl rings);
(IV) R3 and R4 are connected to form a benzene ring fused to the five-membered ring that contains X1, X2, and the nitrogen atom (in which case X2 and the carbon atom in the 5-membered ring next to X2 are also part of said benzene ring); and
(V) R2 and R3 are connected to form a 5-membered or 6-membered N-heterocyclic ring having no substituent, which is fused to the five-membered ring that contains X1, X2, and the nitrogen atom (in which case X1 and the carbon atom in the 5-membered ring connected to R3 are also part of said 5-membered or 6-membered N-heterocyclic rings, R1 is a group as defined in condition (I), and R4 is a group as defined in condition (II)).

### Claim 2 (depends on 1)

The method of claim 1, wherein the carbon dioxide adduct of carbene has a structure represented by formula (II)
wherein R1 and R2 are independently chosen from
hydrogen,
alkyl groups having 1 to 10 carbon atoms,
alkyl groups having 1 to 10 carbon atoms and one or more substituents chosen from halogens, a hydroxyl group, a phenyl group, and a cyano group,
cycloalkyl groups having 3 to 6 carbon atoms,
a halogen atom,
an adamantane group,
a phenyl group, and
a substituted phenyl group;
wherein R3 and R4 satisfy at least one of the following conditions:
(I) R3 and R4 are independently chosen from
hydrogen,
a halogen atom,
a cyano group,
a hydroxyl group,
alkyl groups having 1 to 4 carbon atoms,
alkyl groups having 1 to 4 carbon atoms and one or more substituents chosen from halogens, a hydroxyl group, a phenyl group, and a cyano group,
a phenyl group, and
a substituted phenyl group;
(II) R3 and R4 are connected to form cycloalkyl or cycloalkenyl rings having 3 to 8 carbon atoms fused to the imidazole ring; and
(III) R3 and R4 are connected to form a benzene ring fused to the imidazole ring.

### Claim 3 (depends on 1)

The method of claim 1, wherein the carbon dioxide adduct of carbene has a structure represented by formula (III)
wherein R1 and R2 are independently chosen from
hydrogen,
alkyl groups having 1 to 10 carbon atoms,
alkyl groups having 1 to 10 carbon atoms and one or more substituents chosen from halogens, a hydroxyl group, a phenyl group, and a cyano group,
cycloalkyl groups having 3 to 6 carbon atoms,
a halogen atom,
an adamantane group,
a phenyl group, and
a substituted phenyl group;
wherein R3 and R4 satisfy at least one of the following conditions:
(I) R3 and R4 are independently chosen from
hydrogen,
a halogen atom,
a cyano group,
a hydroxyl group,
alkyl groups having 1 to 4 carbon atoms,
alkyl groups having 1 to 4 carbon atoms and one or more substituents chosen from halogens, a hydroxyl group, a phenyl group, and a cyano group,
a phenyl group, and
a substituted phenyl group; and
(II) R3 and R4 are connected to form a cycloalkyl or cycloalkenyl ring having 3 to 8 carbon atoms fused to the imidazoline ring.

### Claim 4 (depends on 1)

The method of claim 1, wherein the carbon dioxide adduct of carbene has a structure represented by formula (IV)
wherein R1 is chosen from
hydrogen,
alkyl groups having 1 to 10 carbon atoms,
alkyl groups having 1 to 10 carbon atoms and one or more substituents chosen from halogens, a hydroxyl group, a phenyl group, and a cyano group,
cycloalkyl groups having 3 to 6 carbon atoms,
a halogen atom,
an adamantane group,
a phenyl group, and
a substituted phenyl group;
wherein R3 and R4 satisfy at least one of the following conditions:
(I) R3 and R4 can be the same or different and are chosen from
hydrogen,
a halogen atom,
a cyano group,
a hydroxyl group,
alkyl groups having 1 to 4 carbon atoms,
alkyl groups having 1 to 4 carbon atoms and one or more substituents chosen from halogens, a hydroxyl group, a phenyl group, and a cyano group,
a phenyl group, and
a substituted phenyl group;
(II) R3 and R4 are connected to form a cycloalkyl or cycloalkenyl ring having 3 to 8 carbon atoms fused to the thiazole ring; and
(III) R3 and R4 are connected to form a benzene ring fused to the thiazole ring.

### Claim 5 (depends on 1)

The method of claim 1, wherein the carbon dioxide adduct has a structure represented by formula (V)
wherein R1, R2, and R3 satisfy at least one of the following conditions:
(I) R1 and R2 are independently chosen from hydrogen,
alkyl groups having 1 to 10 carbon atoms,
alkyl groups having 1 to 10 carbon atoms and one or more substituents chosen from halogens, a hydroxyl group, a phenyl group, and a cyano group,
cycloalkyl groups having 3 to 6 carbon atoms,
a halogen atom,
an adamantane group,
a phenyl group, and
a substituted phenyl group;
(II) R3 is chosen from
hydrogen,
a halogen atom,
a cyano group,
a hydroxyl group,
alkyl groups having 1 to 4 carbon atoms,
alkyl groups having 1 to 4 carbon atoms and one or more substituents chosen from halogens, a hydroxyl group, a phenyl group, and a cyano group,
a phenyl group, and
a substituted phenyl group; and
(III) R2 and R3 are connected to form a 5-membered or 6-membered N-heterocyclic ring having no substituent, which is fused to the triazole ring, and R1 is a group as defined in condition (I).

### Claim 6 (depends on 1)

The method of claim 1, wherein the substituted phenyl group has one, two, or three substituents, wherein the substituents are independently chosen from halogens, a hydroxyl group, an alkoxy group, a cyano group, alkyl groups having 1-5 carbon atoms, and alkyl groups having 1-5 carbon atoms with one or more substituents chosen from halogens, a hydroxyl group, a phenyl group, and a cyano group.

### Claim 7 (depends on 1)

The method of claim 1, wherein the macrocyclic oligomer contains 3 to 20 cyclic monomer units.

### Claim 8 (depends on 1)

The method of claim 1, wherein a molar ratio of the carbon dioxide adduct of carbene and the cyclic compound is 1:50 to 1:1000.

### Claim 9 (depends on 8)

The method of claim 8, wherein the molar ratio of the carbon dioxide adduct of carbene and the cyclic compound is 1:50 to 1:800.

### Claim 10 (depends on 9)

The method of claim 9, wherein the molar ratio of the carbon dioxide adduct of carbene and the cyclic compound is 1:50 to 1:500.

### Claim 11 (depends on 1)

The method of claim 1, wherein the alcohol initiator is chosen from methanol, ethanol, propanol, isopropanol, n-butanol, tert-butyl alcohol, benzyl alcohol, phenylethyl alcohol, ethylene glycol, diethylene glycol, or pentaerythritol.

### Claim 12 (depends on 11)

The method of claim 11, wherein the molar ratio of the initiator and the cyclic compound is 1:2 to 1:10000.

### Claim 13 (depends on 12)

The method of claim 12, wherein the molar ratio of the initiator and the cyclic compound is 1:50 to 1:500.

### Claim 14 (depends on 1)

The method of claim 1, further comprising heating the reaction mixture to a temperature in the range of 60° C. to 180° C.

### Claim 15 (depends on 14)

The method of claim 14, wherein the temperature is in the range of 100° C. to 160° C.