JPH0794488B2 - Optically active polymerization catalyst and method for synthesizing optically active polymer - Google Patents

Description

The present invention relates to an optically active polymerization catalyst comprising a specific asymmetric ligand compound and an anion initiator compound, and an optically active polymerization catalyst using the polymerization catalyst. A method for synthesizing a polymer.

In particular, the present invention relates to a high performance polymerization catalyst used for asymmetric polymerization of diphenyl-2-pyridylmethyl methacrylate and its derivatives.

[Prior Art and Problems] Conventionally, as a polymerization catalyst for obtaining an optically active polymer,
(−)-Spartine-butyllithium complex and lithium- (R) -N- (1-phenylethyl) anilide are known.

However, these catalysts have the following drawbacks. That is, when the (-)-spartine-butyllithium complex is used, the polymerization rate is slow, and a polymer having a high degree of polymerization and insoluble in ordinary organic solvents is likely to be formed. Lithium-
When (R) -N- (1-phenylethyl) anilide is used, only a polymer having low optical rotation can be obtained.

[Means for solving problems]

As a result of diligent studies on these problems, the present inventors have found a catalyst having novel and extremely excellent performance as an optically active polymerization catalyst, and arrived at the present invention.

That is, the present invention provides the following general formulas (I), (II), (III)
Or an asymmetric ligand compound represented by (IV) [However, R ₁ and R ₄ are R ₂ , R ₃ , R ₅ , R ₆ , R ₁₂ and R ₁₃ are C _{1 to} C ₁₀ alkyl groups;
R ₇ and R ₈ are —O—R ₁₄ , —S—R ₁₄ , R ₉ is R ₁₄ and R ₁₅ represent a C _{1 to} C ₁₀ alkyl group, X is hydrogen, C ₁
To C ₁₀ alkyl group or halogen, n ₁ is 3 or 5
-8, n2 is 3-8, m is 0-2, l is _2-
Which represents the number of 7] and an anion initiator compound, and an optically active polymer obtained by polymerizing a polymerizable monomer using the polymerization catalyst. The present invention relates to a method for synthesizing an active polymer.

The feature of the present invention is that by using the above catalyst, the degree of polymerization of the produced polymer can be easily adjusted and an optically active polymer having a high optical rotation can be obtained.

The asymmetric ligand compound for constituting the optically active polymerization catalyst of the present invention is represented by the above general formula (I), (II), (III) or (IV). Where R ₂ , R ₃ ,
R ₅ , R ₆ , R ₁₂ , R ₁₃ , R ₁₄ and R ₁₅ are preferably methyl groups, X is preferably a methyl group, n ₁ is preferably 5 or 6 and n ₂ is preferably 4 or 5. is there. In addition, a substituent may be attached to the aromatic ring or the heterocycle in the formula.

Examples of such asymmetric ligand compounds include the following formulas (1) to
Examples thereof include compounds having (5). In addition, * indicates an asymmetric carbon atom.

Next, the anionic initiator compound for constituting the optically active polymerization catalyst of the present invention may be one used as an anionic polymerization initiator and capable of forming a complex with the asymmetric ligand compound. Anything will do.

Specifically, an anion initiator comprising an alkali metal, an alkaline earth metal, aluminum or a similar metal as a counter ion and anions such as carbon, nitrogen, oxygen and sulfur as anions is used.

Preferably, there are anion initiators composed of carbon anions, and examples thereof include the following.

_{RMgX, R 2 Mg, RCaX,} Al (C 2 H 5) 3, LiR, LiAlH 4, NaR, KR
(However, R is an alkyl group having 1 to 50 carbon atoms, preferably 1 to 15 carbon atoms, and X is halogen.) Examples of the anionic initiator having an aralkyl group include the following.

Further, an anion initiator obtained from a nitrogen anion, that is, a secondary amine is also preferably used. For example, the secondary amine used as the anion of lithium amide includes the following.

The polymerizable monomer used in the synthesis of the optically active polymer of the present invention may be any one having a vinyl group.

Specifically, α-substituted acrylates such as methacrylic acid esters, acrylic acid esters, N-substituted maleimides, N, N-disubstituted or N-monosubstituted acrylamides and methacrylamides, styrene and styrene derivatives,
Conjugated dienes, methacrylonitrile, acrylonitrile, vinyl pyridine, etc., but especially diphenyl-2-pyridylmethyl methacrylate (D2PyMA) and its derivatives such as diphenyl-2- (6-methylpyridyl) methyl methacrylate (DMPyMA) It was found that an optically active polymer with high activity can be obtained by the asymmetric polymerization of.

A preferred method for preparing the catalyst of the present invention is to mix an anion initiator compound and an asymmetric ligand compound dehydrated and dried in an equimolar amount or slightly higher than the anion initiator compound in a solvent, for example, toluene. The use of the complexed catalyst as a polymerization catalyst. When the polymerizable monomer is polymerized using the polymerization catalyst thus prepared, the polymerizable monomer may be only the polymerizable monomer or may be dissolved in a solvent and polymerized. In this case, the solvent used must not inhibit anionic polymerization.

〔Example〕

Next, preferred examples of the present invention will be shown, but the present invention is not limited to these examples.

Example 1 Diphenyl-2-pyridylmethyl methacrylate (D2PyM
A) is the asymmetric ligand compound of the above formula (2), (3), (4) or (5) and monolithium amide of N, N′-diphenylethylenediamine (DPEDA-Li) or fluorenyllithium ( It was polymerized in toluene at low temperature to obtain an optically active polymer. Reaction conditions are D2PyMA 1g
20 ml of toluene was used to polymerize at -78 ° C. The monomer / Li molar ratio is [D2PyMA] / [Li] = 20, and the asymmetric ligand compound / Li molar ratio is [Ligand] / [Li] = 1.2.
The results of the reaction carried out for 24 hours are shown in Table 1.

Claims (2)

[Claims] 1. An asymmetric ligand compound represented by the following general formula (I), (II), (III) or (IV): [However, R ₁ and R ₄ are R ₂ , R ₃ , R ₅ , R ₆ , R ₁₂ and R ₁₃ are C _{1 to} C ₁₀ alkyl groups;
R ₇ and R ₈ are —O—R ₁₄ , —S—R ₁₄ , R ₉ is R ₁₄ and R ₁₅ represent a C _{1 to} C ₁₀ alkyl group, X is hydrogen, C ₁
To C ₁₀ alkyl group or halogen, n ₁ is 3 or 5
-8, n2 is 3-8, m is 0-2, l is _2-
Represents the number of 7] and an anion initiator compound. 2. An asymmetric ligand compound represented by the following general formula (I), (II), (III) or (IV) [However, R ₁ and R ₄ are R ₂ , R ₃ , R ₅ , R ₆ , R ₁₂ and R ₁₃ are C _{1 to} C ₁₀ alkyl groups;
R ₇ and R ₈ are —O—R ₁₄ , —S—R ₁₄ , R ₉ is R ₁₄ and R ₁₅ represent a C _{1 to} C ₁₀ alkyl group, X is hydrogen, C ₁
To C ₁₀ alkyl group or halogen, n ₁ is 3 or 5
-8, n2 is 3-8, m is 0-2, l is _2-
The number of 7] and an anion initiator compound are used to polymerize a polymerizable monomer to obtain an optically active polymer. Synthesis method.