US 2010O256329A1 (19) United States (12) Patent Application Publication (10) Pub. No.: US 2010/0256329 A1 Nozaki et al. (43) Pub. Date: Oct. 7, 2010

(54) STEREOSELECTIVE ALTERNATING Publication Classification COPOLYMERIZATION OF EPOXDE WITH (51) Int. Cl. CARBON DOXDE C08G 64/00 (2006.01) C07D 207/04 (2006.01) (75) Inventors: Kyoko Nozaki, Tokyo (JP); Koji (52) U.S. Cl...... 528/405; 548/403 Nakano, Tokyo (JP) (57) ABSTRACT Correspondence Address: The present invention provides a method for manufacturing MERCHANT & GOULD PC polycarbonate, which has a high conversion rate of a propy P.O. BOX 2903 lene oxide material into a polymer and can control stereo MINNEAPOLIS, MN 55402-0903 (US) regularity of the macromolecular structure, and a catalytic compound for the manufacturing method. (73) Assignee: The University of Tokyo, The manufacturing method of the present invention is a Bunkyo-ku, Tokyo (JP) method for manufacturing a polycarbonate copolymer by copolymerizing an epoxide compound as a monomer with (21) Appl. No.: 12/663,639 in the presence of a planar tetracoordinate type cobalt-Schiff base complex, wherein a ligand of the Schiff base is N,N'-bis(2-hydroxybenzylidene)ethylenedi (22) PCT Fled: Jun. 6, 2008 amine, N,N'-bis(2-hydroxybenzylidene)phenylenediamine, or a derivative thereof, and a methyl group substituted with an (86) PCT NO.: PCT/UP2008/060813 amino group having an asymmetrical carbon atom or an asymmetrical axis is introduced to the 3- and/or 3'-position of S371 (c)(1), the benzene ring derived from the salicyl group. In addition, (2), (4) Date: Jun. 15, 2010 the catalytic compound of the present invention is a cobalt Schiffbase complex, wherein a methyl group substituted with (30) Foreign Application Priority Data an amino group having an asymmetrical carbon atom or an asymmetrical axis is introduced to the 3- and/or 3'-position of Jun. 8, 2007 (JP) ...... 2007-153322 the salicyl group. US 2010/0256329 A1 Oct. 7, 2010

STEREOSELECTIVE ALTERNATING COPOLYMERIZATION OF EPOXDE WITH OAc CARBON DOXDE TECHNICAL FIELD / 0001. The present invention relates to a method for manu =N e/ o facturing polycarbonate by alternating copolymerization of CO epoxide and carbon dioxide, and a catalyst used for the manu Bu / Y. Bu facturing method. In particular, the present invention relates AcO to a method for manufacturing polycarbonate having a high Stereoregularity and a catalyst used for the manufacturing method.

BACKGROUND ART 0007 As a method for utilizing the above compound 0002 Recently, as a technology for efficient use of carbon which attain such a high Substrate conversion, they reported a dioxide, a method for manufacturing polycarbonate by copo method wherein, after all the first epoxy material (propylene lymerization of epoxide with carbon dioxide has been receiv oxide) is converted to a copolymer, the second epoxy material ing attention. In addition, researchand development aiming at (1-butene oxide) is further added to form a different polymer novel properties and functions, and expansion ofuses thereof, chain at the end of the first polymer chain, and thereby a block by controlling the stereoregularity of polycarbonate, are copolymer is manufactured. being carried out. DISCLOSURE OF THE INVENTION 0003 For example, control of stereoregularity by regu larly introducing an optically-active center in the main chain 0008. However, in the synthesis of a polycarbonate of polycarbonate is being investigated. An optically active copolymer, a catalyst which has Superior enantioselectivity and yet shows a high Substrate conversion has not been polycarbonate, which is obtained by alternating copolymer reported. Therefore, in order to further expand the possibility ization of one of the enantiomers of chiral epoxide with of controlling the stereoregularity of polycarbonate copoly carbon dioxide, has a main-chain structure with very high mers and realize a variety of Stereosequence of polycarbon Stereoregularity, and is predicted to display Superior mechani ate, the development of Such a catalytic compound is a new cal and physico-chemical properties, and therefore applica challenge. tion of a separation medium for chromatography and separa 0009. The present invention provides a method for manu tion membrane, a biodegradable material, a ferroelectric facturing a polycarbonate copolymer by copolymerizing an material, and a piezoelectric pyroelectric material is envi epoxide compound as a monomer with carbon dioxide in the Sioned. presence of a planar tetracoordinate-type cobalt-Schiff base complex, wherein a ligand of the Schiff base is N,N'-bis(2- 0004 While the above optically active polycarbonate hydroxybenzylidene)ethylenediamine (salen), N,N'-bis(2- could be manufactured by using one of the enantiomers of a hydroxybenzylidene)phenylenediamine (salph) or a deriva chiral epoxide, a chiral epoxide is usually obtained as a race tive thereof, and a methyl group Substituted with an amino mic mixture, and hence in the above manufacturing method, group having an asymmetrical carbonatom or an asymmetri an enantiomerically pure epoxide has to be prepared, which is cal axis, is introduced to the 3- and/or 3'-position of the very expensive. On the other hand, an optically active poly benzene ring derived from the salicyl group. carbonate can be synthesized through enantioselective alter 0010. In addition, another aspect of the present invention provides a cobalt-Schiff base complex usable as a polymer nating copolymerization with carbon dioxide, where one of ization catalyst for manufacturing polycarbonate, wherein a the enantiomers of a racemic epoxide is selectively copoly methyl group Substituted with an amino group having an merized. Therefore, studies aiming at the development of an asymmetrical carbon atom or an asymmetrical axis is intro enantioselective alternating copolymerization reaction using duced to the 3- and/or 3'-position of the salicyl group. a racemic mixture of epoxide are being carried out. 0011. The cobalt complex compound of the present inven 0005 X. Lu, et al. reported that they attempted an alter tion attain a high enantioselectivity when using a racemic nating copolymerization reaction of a racemic mixture of mixture of epoxide. Therefore, a variety of polycarbonate epoxide with carbon dioxide, using a binary catalyst of a copolymers with a controlled Stereoregularity can be manu Schiff base-cobalt complex in combination with a nucleo factured from the racemic mixture of epoxide and carbon philic reagent to obtain optically active polycarbonate (J. Am. dioxide. Chem. Soc., 2006, 128, 1664-1674). BEST MODE FOR CARRYING OUT THE 0006 K. Nakano, et al. discovered that, in the case when INVENTION the following compound belonging to the Schiffbase-cobalt 0012. The cobalt complex used as a catalyst in the present complex was used by itself, it could suppress the formation of invention comprises a Schiffbase that is a planartetra-dentate by-product, cyclic carbonate, and the conversion of the pro ligand. The typical Schiffbase ligand is a salen ligand (N,N'- pylene oxide to polycarbonate was about 80%, although the bis(salicylidene)ethylenediamine) and a derivative thereof enantioselectivity was not observed (Angew. Chem. Int. Ed, (hereinafter, referred to as a “salen-type ligand'). The salen 2006, 45,7274-7277). type ligand is obtained by a dehydration condensation reac US 2010/0256329 A1 Oct. 7, 2010 tion of Salicylaldehyde and ethylenediamine, and by using another diamine instead of ethylenediamine or by introducing -continued a Substituent in the aromatic ring part of Salicylic acid, a NR: variety of derivatives can be obtained. Specifically preferable compounds among Such derivatives are the Salcy ligand (N,N'-bis(salicylidene)-1,2-cyclohexanediamine) which is obtained by modifying the ethylenediamine part of the salen O ligand to cyclohexanediamine and a derivative thereof, or the salph ligand (N.N'-bis(salicylidene)-phenylenediamine), in MeO| Ph MeO which the ethylenediamine part is replaced by phenylenedi Ph amine, and a derivative thereof. 0013. A methyl group substituted with an amino group having an asymmetrical carbon center or an asymmetrical 0017 wherein, axis (hereinafter, referred to as an 'arm') can be introduced to 0018 X represents any one group or atom selected from the 3- and/or 3'-position of the Salicyl group contained in the group consisting of H. C.20 alkyl, C-2 alkoxy, C-2 these salen-type ligands. In the case when the arms are intro aryl, F, Cl, Br, and I, and Y represents an anionic ligand duced into both 3- and 3'-positions, the two substituents may selected from the group consisting of aliphatic carboxylate, be the same or different. The amino group constituting the aromatic carboxylate, Cl, Br, and I. arm may be a tertiary amino group, preferably is a pyrrolidi 0019. A specifically preferable cobalt-Schiff base com nyl group or a piperidinyl group, and most preferably is a plex of the present invention is the compound represented by pyrrolidinyl group. Thus, for example, in the case when the the following formula. amino group constituting the arm is a pyrrolidinyl group with a single Substituent, the carbon of the 5-membered ring to which the substituent is bound is the asymmetrical center, showing optical activity. Below, specific examples of the arm N are shown (Note: they are not limited to the following sub O stituents). / N / o N e/ o MeO Ph MeO Ph Bu O/"\, Bu O 0014. The absolute configuration around the asymmetri cal carbon center or the asymmetrical axis defining the con figuration of the amino group constituting the arm is either 1s. (R) or (S). The absolute configuration of the arm can be RN NHR selected and introduced depending on the absolute configu NR : ration of a polycarbonate having the desired optical activity. 0015 The central metal of the above cobalt complex is involved in the polymerization reaction of the present inven O tion, and so one or two reactive ligands can coordinate along t N the axial directions of the central metal so that the cobalt MeO Ph metal can easily react with the substrate. The most typical MeO ligands are carboxylates, halogens, etc., and a preferable one Ph is acetonate (AcO). 0016 Consequently, a preferable cobalt-Schiffbase com 0020. The catalytic system used in the present invention plex is the compound represented by the following formula: shows by itself a sufficient catalytic activity and displays a Superior enantioselectivity without the use of a promoter Such as a nucleophilic reagent, or the like. Further, in the present invention, as well as conventional catalytic systems used for manufacturing a polycarbonate copolymer, a combined cata lyst system of a cobalt-Schiff base complex in combination with a promoter Such as a nucleophilic reagent, or the like, may be used. 0021. In addition, the catalyst of the present invention is characteristic in that the Substrate conversion can reach to 100% (That is, it is possible to consume the substrate com pletely). In relation with this characteristic, the present inven tion has a preferable aspect as shown below. 0022. Namely, when an alternating copolymerization of a racemic mixture of chiral epoxide as a monomer with carbon dioxide is carried out in the presence of a catalyst of the RN present invention, one of the enantiomers of the monomer is selectively consumed at the beginning, and so until this enan US 2010/0256329 A1 Oct. 7, 2010

tiomer is completely consumed, an optically active polymer 0031. The molar ratio of one of the enantiomers of preferentially containing an asymmetrical carbon center with epoxide, which is preferentially incorporated in one block, either the S or R absolute configuration in a polymer main can be a value of 60% or more, preferably 70% or more, and chain is produced. more preferably 75% or more, based on the total amount of 0023 Therefore, according to one aspect of the present the epoxide monomer incorporated in the block. invention, one of the enantiomers contained in the monomer 0032. An epoxide compound usable as a monomeric mate is selectively consumed, and thus an optically active polycar rial for the manufacturing method of the present invention bonate preferentially containing an asymmetric carbon center comprises both a chiral epoxide and a meso-epoxide. Specifi with either the S or R absolute configuration in a polymer cally, it can comprise epoxides represented by the following main chain can be manufactured, by terminating the polymer formula: ization reaction with a reaction terminator, before this enan tiomer is completely consumed. 0024. In addition, when one of the enantiomers is com RI pletely consumed for the polymerization reaction in the pres ence of the catalyst of the present invention followed by a further polymerization reaction, the another enantiomer, Ob which was unused, is incorporated into the polymer main chain, and a polymer chain with an absolute configuration 0033 wherein, opposite to that of the above polymer chain is added. 0034) R' and R may be the same or different with the 0025. Therefore, according to another aspect of the proviso that they are not concurrently a hydrogen atom, and present invention, after one of the enantiomers is completely further, R' and R are independently a hydrogen atom, a consumed, a further polymerization reaction can manufac halogen atom, a substituted amino group (-NRR), cyano, ture a polycarbonate comprised of a block which preferen linear or branched C to Co alkyl, C. to Coalkenyl or C to tially contains an asymmetrical carbon center with the S Coalkynyl, Cato Co cycloalkyl, C to Cao aryl or C7 to Cao absolute configuration and a block which preferentially con arylalkyl, or tains an asymmetrical carbon center with the Rabsolute con I0035) R' and R together may form a saturated or unsat figuration in one polymer chain. urated C to Coalicyclic group: 0026. Further, when an alternating copolymerization 0036 the aryl moiety in the aryl or arylalkyl and the ali using a meso-epoxide compound as a monomer with carbon cyclic group may be substituted with one or more substituents dioxide in the presence of a catalyst of the present invention is selected from the group consisting of a halogen atom, linear carried out, ring opening of the epoxy ring and polymeriza or branched C to Co alkyl, C. to Coalkenyl or C to Co tion occur stereoselectively. alkynyl, and C to Co cycloalkyl, or 0027. Therefore, according to a further different aspect of 0037 two substituents bound to two adjacent carbons in the present invention, polycarbonate comprised of asym the aryl ring may together form a saturated or unsaturated Ca metrical carbon centers with only either the (R,R) or (S,S) to Coalicyclic group: absolute configuration in a polymer main chain and having a 0038 the alkyl, alkenyl, alkynyl and cycloalkyl, aryl and high Stereoregularity (and yet having optical activity) can be alicyclic groups may contain at least one heteroatom, wherein the heteroatom is at least one atom selected from the group manufactured. consisting of nitrogen, oxygen, Sulfur, phosphorus, and sili 0028. In addition, according to the manufacturing method COn; utilizing a catalyst of the present invention, it is possible to 0039 the halogen is at least one atom selected from the completely consume the Substrate, and so complete con group consisting of fluorine, chlorine, bromine, and iodine, sumption of the first epoxide followed by addition of the same 10040. Rand Rare linear or branched C, to Coalkyl, C. epoxide or a different second epoxide can synthesize a block to Coalkenyl or C to Coalkynyl, Cato Cocycloalkyl, or C. polymer having a high Stereoregularity. to Cao aryl or C7 to Cao arylalkyl, or 0029. Therefore, according to the manufacturing method I0041) R' and R together may form a saturated or unsat of the present invention, the adequate adjustment not only of urated C to Coalicyclic group; and further the component ratio of the enantiomers contained in the 0042 the heteroatom can be present in the following monomer, but also of the type of epoxide and the order of forms: addition enables to manufacture a variety of polycarbonate 0043 an oxygenatom may be involved in the alkyl chain copolymers having controlled Stereoregularity. of the alkyl and arylalkyl to form an ether bond, thereby 0030 A preferable aspect of the present invention com forming an aryloxy group. In addition, oxygen may form prises polycarbonate having a novel block copolymer struc carbonyl (C=O) with a carbon atom of an alkyl chain (in ture. Namely, the polycarbonate of the present invention is a cluding both cyclic and noncyclic), block copolymer comprised of a block which preferentially 0044 it may provide an ester structure or an amide struc contains an asymmetrical carbon center with the S absolute ture together with oxygen or nitrogen adjacent to the carbo configuration and a block which preferentially contains an nyl: asymmetrical carbon center with the Rabsolute configuration 0045 when S is present in place of oxygen, it can form a in a polymer main chain. Further, the polycarbonate of the structure such as thioether, thionyl (C=S), thioester, and the present invention is a block copolymer comprised of a block like. which contains an asymmetrical carbon center with only the 0046 More preferably, the epoxide compound usable for Sabsolute configuration and a block which contains an asym the manufacturing method of the present invention is a chiral metrical carbon center with only the Rabsolute configuration epoxide or a meso-epoxide represented by the following for in a polymer main chain. mula: US 2010/0256329 A1 Oct. 7, 2010

can continue in the presence of excess amounts of carbon dioxide until the epoxide is completely consumed, or after RI Sufficient progression of the reaction over several to several tens of hours, the reaction may be terminated with an adequate reaction terminator. Any reaction terminator is Ob usable without particular restriction as far as it is a conven tional reagent for terminating the polymerization reaction for 0047 wherein, polycarbonate. For example, a compound having an active 0048) R' and R may be the same or different with the proton Such as (for example, methanol), water, acid proviso that they are not concurrently a hydrogen atom, and (for example, hydrochloric acid) can be used. After the alter further, R' and Rare independently a hydrogenatom, linear nating copolymerization is finished, the unreacted material or branched C to Cs alkyl, C. to Cs alkenyl or C to Cs and the (when a solvent is used) are distilled away, and alkynyl, C to Cs cycloalkyl, or C to Caryl or C, to Co the resulting reaction product is purified by an adequate arylalkyl, or means such as reprecipitation or others. I0049) R' and R together may form a saturated or unsat 0059. The molecular weight of the polycarbonate manu urated C to Calicyclic group; factured by the present invention is typically 1,000 or higher, 0050 the aryl moiety in the aryl or arylalkyl and the ali preferably is 2,000 to 1,000,000, and even more preferably cyclic group may be substituted with one or more Substituents 3,000 to 100,000, based on the number average molecular selected from the group consisting of a halogen atom, linear weight M, measured by gel permeation chromatography or branched C to Cs alkyl, C. to Cs alkenyl or C to Cs (GPC; polystyrene equivalent). alkynyl, and C to Cs cycloalkyl, or 0060. The optically active polycarbonate obtained by the 0051 two substituents bound to two adjacent carbons in manufacturing method of the present invention can possess a the aryl ring may together form a saturated or unsaturated Ca relatively narrow molecular weight distribution (M/M). to Csalicyclic group: Specifically, it is less than 4, more preferably less than 2.5, 0052 the alkyl, alkenyl, alkynyl and cycloalkyl, aryland and most preferably is approximately 1.0 to approximately alicyclic groups may contain at least one heteroatom, 1.6. 0053 the halogen is at least one atom selected from the group consisting of fluorine, chlorine, bromine, and iodine. 0054 As a specific example for an specifically preferable EXAMPLES chiral epoxide as the monomer for the manufacturing method of the present invention, , 1-butene oxide, 0061 The present invention is more specifically explained 1-pentene oxide, 2-pentene oxide, 1-hexene oxide, 1-octene by the following examples; however, the present invention is oxide, 1-dodecene oxide, styrene oxide, vinylcyclohexene not limited to these examples. oxide, 3-phenylpropylene oxide, 3,3,3-trifluoropropylene I0062. The measurement of H NMR spectrum of the com oxide, 3-naphthylpropylene oxide, butadiene monoxide, pounds obtained in the examples of the present invention was 3-trimethylsilyloxypropylene oxide, etc., are exemplified, carried out using a JNM-ECP500 (500 MHz) manufactured and above all, propylene oxide is preferable. These chiral by JEOL Ltd. epoxides are usable as a racemic mixture (Note: it is not 0063. The molecular weight of optically active polycar limited to these). bonate was measured by using a high performance liquid 0055 Likewise, as a specific example for an specifically chromatography system (DG660B/PU713/UV702/RI704/ preferable meso-epoxide as the monomer, 2-butene oxide, C0631A) manufactured by GL Sciences Inc., and two Shodex cyclopentene oxide, and cyclohexene oxide are exemplified KF-804F columns manufactured by Showa Denko, K.K. with (Note: it is not limited to these). tetrahydrofuran as an eluate (40°C., 1.0 mL/min), standard 0056. On the other hand, carbon dioxide which is sub ized with a polystyrene standard, and was obtained by pro jected to copolymerization with a chiral epoxide is introduced cessing the data with analysis software (EZChrom Elite into a reaction vessel in a gaseous form, and used for the manufactured by Scientific Software, Inc.). reaction. In addition, the alternating copolymerization reac 0064. Further, in the examples of the present invention, the tion of the present invention is preferably carried out under optical purity of the optically active epoxide, which was not inert atmosphere in order to exclude the influence of oxygen, reacted, was estimated by the enantiomeric excess percentage etc., and so carbon dioxide coexists with an inert gas in the (% ee) which is calculated by converting the epoxide to a reaction vessel. The carbon dioxide pressure in the reaction corresponding cyclic carbonate. In order to obtain the enan vessel is 0.1 to 6 MPa, and preferably is 1.0 to 3.0 MPa. The tiomeric excess percentage, measurement was carried out by molar ratio of epoxide to carbon dioxide which are used for using a gas chromatograph system (GC-2010) manufactured the reaction is typically 1:0.1 to 1:10, preferably is 1:0.5 to by Shimadzu Corporation and an analytical column (CHIRA 1:30, and more preferably is 1:1.0 to 1:2.0. SIL-DEXCB manufactured by Chrompack Inc.) with helium 0057 The copolymerization reaction of the present inven as a carrier gas. The enantiomeric excess percentage was tion may be carried out in a solvent or without the use of a estimated according to the following formula with the peak solvent. When a solvent is used, toluene, methylene chloride, areas (referred to as A and As for the peak area of the Rand 1.2-dimethoxyethane, etc., may be used, and 1,2-dimethoxy S isomers, respectively) ethane is preferable. 0058. The alternating copolymerization of the present Enantiomer excess percentage (% ee)=100x|A-As? invention can be carried out at a temperature in the range of (AR+AS) approximately 0 to 60° C., and in general, it is carried out at 0065. Further, the following indicator(k) representing a room temperature. The alternating copolymerization reaction selectivity showing which enantiomer of the racemic body US 2010/0256329 A1 Oct. 7, 2010

was preferentially incorporated into the polymer was esti mL) were put into a 20 mL Schlenk flask, to which (S)-2- mated according to the formula below. (diphenylmethoxymethyl)pyrrolidine (S)-4, 450 mg, 1.7 mmol dissolved in tetrahydrofuran (20 mL) was slowly kilnrei 1-c(1+ee). In 1-c(1-ee) added. After stirring at 25°C. for 2 hours, the resulting pre 0.066 Here, ee is the enantiomeric excess of the unreacted cipitate was filtered off, and the filtrate was concentrated to epoxide obtained by the above method, and c is the conver give a salicylaldehyde derivative (S)-5 (384 mg. 84% yield). sion of epoxide. (0073 "H NMR (CDC1,500 MHz) & 10.29 (s, 1H), 7.56 7.50 (m, 5H), 7.40-7.29 (m, 8H), 4.36 (d. J=13.5 Hz, 1H), (1) Preparation of the Catalyst 3.99 (dd, J=9.9, 4.1 Hz, 1H), 3.68 (d. J=13.7 Hz, 1H), 2.96 (s, 3H), 2.38-2.34 (m, 1H), 2.20-2.15 (m, 1H), 2.10-2.02 (m, 0067. and tetrahydrofuran used as sol 1H), 1.86-1.80 (m, 1H), 1.46-140 (m. 1H), 1.30 (s, 9H), vents in the synthesis examples below were of anhydrous 0.72-0.62 (m. 1H). grade obtained from Kanto Chemical Co., Inc. and were used after passed through a solvent purifying apparatus manufac CHO tured by Glass Contour. Ethanol obtained from Kanto Chemi cal Co., Inc. was used, without purification. 0068 Cobalt acetate was obtained from Kanto Chemical Bu OH Co., Inc. Glacial acetic acid was obtained from Aldrich Chemical Co., Inc., and was used without purification. (1R, 2R)-1,2-diaminocyclohexane was obtained from Tokyo Chemical Industry Co., Ltd. and used without purification. (S)-2-(diphenylmethoxymethyl)pyrrolidine was prepared according to the method described in the publications (1) Enders, D.; Kipphardt, H.; Gerdes, P.; Brena-Valle, L. J.; Bhushan, V. Bull. Soc. Chim. Belg. 1988, 8-9, 691-704. (2) Ho, C.Y.; Chen, Y.C.; Wong, M. K. Yang, D. J. Org. Chem. 2005, 70, 898-906.). 0069 Salicylaldehyde derivative 3 used as a material in the following ligand synthesis was prepared according to the publication (DiMauro, E. F. Kozlowski, M. C. Org. Lett. HN NH2

2001, 3,3053-3056). (1R,2R)-6 0070 Further, the known Schiff base compound la used for the following complex synthesis was prepared according to the publication (DiMauro, E. F.; Kozlowski, M. C. Org. Lett. 2002, 4, 3781-3784). N N Synthesis Example A Synthesis of a Novel Schiff Base Compound Bu OH HO Bu A-1. Synthesis of Salcy Ligand 1b 0071 CHO Ph --> Bu OH + Ph -> N H Br On 3 (S)-4 CHO (0074 The obtained salicylaldehyde derivative (S)-5 (178 Bu OH mg, 0.39 mmol) was dissolved in ethanol (1.0 mL) and meth ylene chloride (3.0 mL), to which (1R,2R)-1,2-diaminocy clohexane (1R,2R)-6, 22 mg, 0.19 mmol dissolved in etha N nol (3.0 mL) was added. After stirring at 25°C. for 12 hours, the resulting mixture was concentrated to give the desired salcy ligand 1b (190 mg, 99% yield). O Ph 0075 "H NMR (CDC1,500 MHz) & 8.24 (s. 2H), 7.63 (d. / Ph J=7.3 Hz, 4H), 7.60 (d. J=7.6 Hz, 4H), 7.40-7.21 (m, 16H), (S)-5 6.95 (d. J=2.1 Hz, 2H), 3.99 (dd, J=9.6, 3.2 Hz, 2H), 3.92 (d. J=13.1 Hz, 2H), 3.81 (d. J=14.2 Hz, 2H), 3.30-3.25 (m, 2H), 2.90 (s, 6H), 2.45-2.39 (m, 2H), 2.10-2.03 (m, 2H), 2.00- 1.60 0072 Under argon gas atmosphere, salicylaldehyde (m. 12H), 1.48-141 (m, 2H), 1.22 (s, 18H), 0.38-0.29 (m, derivative 3 (248 mg, 0.91 mmol) and tetrahydrofuran (10 2H). US 2010/0256329 A1 Oct. 7, 2010

Synthesis Example B Synthesis of a Novel Cobalt-Schiff Base Complex B-1. Synthesis of Complex 2a 0076

1) Glacial acetic acid (5.0 equivalent) Co(OAc) Bu OH HO CH2Cl2 2) Reduced 25°C., 15 min pressure 35° C., 2.5 hr drying

la

Bu O

2a 0077 Under argon gas atmosphere, cobalt acetate (29 mg, (0078 H NMR (CDC1,500MHz) & 7.64(s, 2H), 7.40 (d. 0.16 mmol), salcy ligand 1a (110 mg, 0.16mmol), and dichlo J–2.2 Hz, 2H), 7.29 (d. J=2.2 Hz, 2H), 5.21 (d. J=12.1 Hz, romethane (1.0 mL) were put into a 20 mL Schlenk flask. The 2H), 4.31 (d. J=12.1 Hz, 2H), 4.12-4.06 (m, 2H), 4.01 (d. resulting mixture was stirred at room temperature for 15 min, J=8.2 Hz, 2H), 3.93-3.88 (m. 2H), 3.76-3.71 (m, 2H), 3.67 and then at 35°C. for 2.5 hours. Glacial acetic acid (65 mL) 3.62 (m. 2H), 3.49-3.41 (m, 6H), 2.91 (d. J=11.0 Hz, 2H), dissolved in dichloromethane (2.0 mL) was added and stirred 2.06-1.86 (m. 10H), 1.77-1.68 (m, 4H), 1.60- 1.54 (m. 2H), in the presence of air for 3.5 hours. After removal of volatile 1.34-1.24 (m, 24H). components under reduced pressure, followed by sufficient drying, the desired cobalt complex 2a was quantitatively B-2. Synthesis of Complex 2b obtained as a red-brown solid. 0079

1) Glacial acetic acid (5.0 t equivalent) Co(OAc)2 + Bu OH HO Bu -o-CH2Cl2 -e-2) Reduced 25°C., 15 min pressure 35° C., 2.5 hr drying

1b US 2010/0256329 A1 Oct. 7, 2010

-continued OAc

/e =N -N= Ph Ph Co Bu Y N Bu R = o1 AcO

GE) N H-N

2b

0080 Under argon gas atmosphere, cobalt acetate (23 mg, 0.13 mmol), salcy ligand 1b (127 mg, 0.13 mmol), and -continued dichloromethane (1.0 mL) were put into a 20 mL Schlenk flask. The resulting mixture was stirred at room temperature for 15 min, and then at 35° C. for 2.5 hours. After the tem perature was lowered to 25°C., glacial acetic acid (50 mL) dissolved in dichloromethane (2.0 mL) was added and stirred in the presence of air for 3 hours. After removal of volatile propylene components under reduced pressure, followed by sufficient carbonate CopolymerSubstrate conversion: selectivity: 32% >99% drying, the desired cobalt complex 2b was quantitatively Number average molecular weight: 15.400 gemol obtained as a red-brown solid. Polydispersity; 1.12 (2) Manufacturing of Polycarbonate I0085 Under argon gas atmosphere, cobalt complex 2a 0081 Propylene oxide used in the following polymeriza (12.4 mg., 0.014 mmol) and propylene oxide (2.0 mL, 28.6 tion experiments was obtained from Tokyo Chemical Indus mmol) were put into an autoclave, to which carbon dioxide try Co., Ltd., and dehydrated with calcium hydride, and then (1.4MPa) was injected and then stirred at 25°C. for 12 hours. distilled under argon atmosphere. The carbon dioxide pressure was released, and a most part of 0082 Complex 6 used for manufacturing polycarbonate the unreacted propylene oxide was recovered under reduced below was prepared according to the above-described K. pressure. After a solid crude product remaining in the auto Nakano, et al., Angew. Chem. Int. Ed, 2006, 45,7274-7277. clave was transferred with dichloromethane into a round 0083. The substrate conversion was estimated according bottom flask, followed by concentration and vacuum drying, to the following. Namely, after the polymerization, phenan a crude product of copolymer was obtained. 32% NMR yield threne was added as an internal standard to the reaction mix (internal standard substance: phenanthrene), C-10 ture, a part of the resulting mixture was extracted, and then a (c=0.50, CHCl). H NMR measurement was carried out. According to the individual peak areas of phenanthrene, polypropylene car bonate (PPC), and propylene carbonate (PC), yields of PPC NaI, PPhi, PhOH and PC were estimated, and their sum was regarded as the --- Substrate conversion. OD1 co, 120° C., 5 hr O O r Example 1 propylene carbonate Manufacturing of Polypropylene Carbonate Using Enantiomeric excess percentage: 13.3% R-isomer Cobalt Complex 2a of the Present Invention 0084 I0086. The unreacted epoxide which was recovered, sodium iodide (21 mg, 0.14 mmol), triphenylphosphine (38 mg, 0.14 mmol), and phenol (14 mg., 0.14 mmol) were put cobalt complex 2a into an autoclave, to which carbon dioxide (4.0 MPa) was + CO2 - - O O -- injected and then stirred at 120° C. for 5 hours. The carbon O 259 C., 12 hr r pi dioxide pressure was released, and a part of the reaction mixture was extracted to determine the enantiomeric excess O polypropylene percentage of the resulting propylene carbonate by gas chro carbonate matography (13.3% ee). k.re 2.0 was calculated according to the above formula. US 2010/0256329 A1 Oct. 7, 2010

Example 2 Comparative Example 1 Manufacturing of Polypropylene Carbonate Using Manufacturing of Polypropylene Carbonate Using the Known Cobalt Complex 6 Cobalt Complex 2b of the Present Invention 0090 0087

cobalt complex 6 + CO2 - - O O -- O 259 C., 2 hr r pi cobalt complex 2b O CO- - - - polypropylene D-1 -- 2 259 C., 84 hr ().pi -- carbonate OAc O polypropylene carbonate /e EN NE O N/

y- O Bu O/\ O Bu O AcO propylene carbonate e Substrate conversion: 28% Copolymer selectivity: 87% Number average molecular weight: 13.400 gemol Polydispersity; 1.16 () "K) propylene cobalt complex 6 carbonate 0088 Under argon gas atmosphere, cobalt complex 2b (17 Substrate conversion: 30% Copolymer selectivity: 98% mg, 0.014 mmol) and propylene oxide (2.0 mL, 28.6 mmol) Number average molecular weight: 12.200 gemol were put into an autoclave, to which carbon dioxide (1.4MPa) Polydispersity; 1.15 was injected and then stirred at 25° C. for 84 hours. The 0091 Under argon gas atmosphere, cobalt complex 6 (12 carbon dioxide pressure was released, and a most part of the mg, 0.014 mmol) and propylene oxide (2.0 mL, 28.6 mmol) unreacted propylene oxide was recovered under reduced were put into an autoclave, to which carbon dioxide (1.4MPa) pressure. After a solid crude product remaining in the auto was injected and then stirred at 25°C. for 2 hours. The carbon clave was transferred with chloroform into a round-bottom dioxide pressure was released, and a most part of the unre acted propylene oxide was recovered under reduced pressure. flask, followed by concentration and vacuum drying, a crude After a solid crude product remaining in the autoclave was product of copolymer was obtained. 24% NMR yield (inter transferred with chloroform into a round-bottom flask, fol nal standard Substance: phenanthrene). lowed by concentration and vacuum drying, a crude product of copolymer was obtained. 29% NMR yield (internal stan dard Substance: phenanthrene).

NaI, PPhi, PhOH --- O OD-1 . CO 120° C., 5 hr O NaI, PPhi, PhOH ^1 OD-1 + CO2 - 120° C., 5 hr - ) O O r propylene O carbonate propylene Enantiomeric excess percentage: 15.4% R-isomer carbonate Enantiomeric excess percentage: 0%

0089 The unreacted epoxide, which was recovered, 0092. The unreacted epoxide which was recovered, sodium iodide (21 mg, 0.143 mmol), triphenylphosphine (38 sodium iodide (21 mg, 0.14 mmol), triphenylphosphine (38 mg, 0.143 mmol), and phenol (14 mg., 0.143 mmol) were put mg, 0.14 mmol), and phenol (14 mg., 0.143 mmol) were put into an autoclave, to which carbon dioxide (4.0 MPa) was into an autoclave, to which carbon dioxide (4.0 MPa) was injected and then stirred at 120° C. for 5 hours. The carbon injected and then stirred at 120° C. for 5 hours. The carbon dioxide pressure was released, and a part of the reaction dioxide pressure was released, and a part of the reaction mixture was extracted to determine the enantiomeric excess percentage of the resulting propylene carbonate by gas chro mixture was extracted to determine the enantiomeric excess matography (0% ee).k, 1.0 was calculated according to the percentage of the resulting propylene carbonate by gas chro above formula. matography (15.4% ee).kre =2.7 was calculated according to 0093. The results of Examples 1 and 2, and Comparative the above formula. Example 1 are compared and shown in the table below. US 2010/0256329 A1 Oct. 7, 2010

Comparison of the Results of Examples 1 and 2, and Comparative Example 1 -continued OAc 0094)

Number average Reaction molecular weight Polydispersity rate ratio ye Catalyst (g mol) M.M., kre ry- -N.-N= 2a 15,400 1.12 2.O 2b 13,700 1.16 2.7 y-d Bu ^ Yo Bu 6 12,200 1.15 1 O AcO

e Example 3 Manufacturing of Polypropylene Carbonate Using Cobalt Complex 2a of the Present Invention (the propylene cobalt complex 6 Case When a High Substrate Conversion Rate was carbonate Substrate conversion: 79% Attained) Copolymer selectivity: 96% Number average molecular weight: 83,700 gemol 0095 Polydispersity; 1.28 0.098 Under argon gas atmosphere, cobalt complex 6 (5.9 mg, 0.0073 mmol) and propylene oxide (3.3 mL, 47.2 mmol) D-1 + CO2 cobalt complex 2a O O -- were put into an autoclave, to which carbon dioxide (1.4MPa) O room temp., 78 hr was injected and then stirred at 25° C. for 116 hours. The pi carbon dioxide pressure was released, and a most part of the O unreacted propylene oxide was recovered under reduced polypropylene pressure. After a solid crude product remaining in the auto carbonate clave was transferred with chloroform into a round-bottom flask, followed by concentration and vacuum drying, a crude product of copolymer was obtained. 76% NMR yield (inter try nal standard Substance: phenanthrene). y-d 1. A method for manufacturing a polycarbonate copolymer O by copolymerizing an epoxide compound as a monomer with propylene carbon dioxide in the presence of a planar tetracoordinate carbonate type cobalt-Schiff base complex, wherein a ligand of the Substrate conversion: 84% Schiff base is N,N'-bis(2-hydroxybenzylidene)ethylenedi Copolymer selectivity: s99% amine, N,N'-bis(2-hydroxybenzylidene)phenylenediamine, Number average molecular weight: 39,800 gemol or a derivative thereof, and a methyl group substituted with an Polydispersity; 1.16 amino group having an asymmetrical carbon atom or an asymmetrical axis is introduced to the 3- and/or 3'-position of 0096 Under argon gas atmosphere, cobalt complex 2a (12 the benzene ring derived from the Salicyl group. mg, 0.014 mmol) and propylene oxide (2.0 mL, 28.6 mmol) 2. A method according to claim 1, wherein the monomer is were put into an autoclave, to which carbon dioxide (1.4MPa) a racemic mixture of a chiral epoxide compound. was injected and then stirred at 25° C. for 78 hours. The 3. A method according to claim 2 comprising, carbon dioxide pressure was released, and a most part of the terminating the polymerization reaction by a reaction ter unreacted propylene oxide was recovered under reduced minator before one of the enantiomers contained in the pressure. After a solid crude product remaining in the auto monomer is completely consumed in the polymerization clave was transferred with chloroform into a round-bottom reaction, to obtain polycarbonate preferentially contain flask, followed by concentration and vacuum drying, a crude ing an asymmetric carbon center with either the S or R product of copolymer was obtained. 84% NMR yield (inter absolute configuration in a polymer main chain. nal standard Substance: phenanthrene). 4. A method according to claim 2 comprising, Comparative Example 2 continuing the polymerization reaction even after one of the enantiomers contained in the monomer is completely Manufacturing of Polypropylene Carbonate Using consumed, to obtain polycarbonate comprised of a block which preferentially contains an asymmetrical carbon the Known Cobalt Complex 6 (the Case When a center with the S absolute configuration and a block High Substrate Conversion Rate was Sought) which preferentially contains an asymmetrical carbon 0097 center with the R absolute configuration in a polymer main chain. 5. A method according to claim 1, wherein the monomer is a meso-epoxide compound.

D-1 CO --cobalt complex 6 O O 6. A method according to claim 1, further comprising, O * 2 so c. 116 he -- after the monomer is completely consumed in the alternat pi ing copolymerization reaction with carbon dioxide, car O rying out an alternating copolymerization reaction with polypropylene carbon dioxide by adding either the same epoxide com carbonate pound or a different kind of epoxide compound from the one used as the monomer. US 2010/0256329 A1 Oct. 7, 2010

7. A method according to claim 1, wherein the Schiffbase 12. A compound represented by the following formula: is N,N'-bis(2-hydroxybenzylidene)cyclohexanediamine. 8. A method according to claim 1, wherein the amino group is a pyrrolidinyl group, and the pyrrolidinyl group is Substi tuted so that the carbon atom at the 2-position is the asym metrical center. 9. A method according to claim 8, wherein the pyrrolidinyl group is any one group selected from the group consisting of an (S)-2-methoxymethyl-1-pyrrolidinyl group and an (S)-2- diphenyl(methoxy)methyl-1-pyrrolidinyl group. 10. A method according to claim 1, wherein the cobalt Schiff base complex is a ound represented by the fol lowing formula:

RN NHR2

NR:

RN NHR2 O NR: t N MeO Ph MeO Ph t O N MeO Ph wherein, MeO X represents any one group or atom selected from the Ph group consisting of H. Co alkyl, C-2 alkoxy, C-20 wherein, aryl, F, Cl, Br, and I, and Y represents an anionic ligand X represents any one group or atom selected from the Selected from the group consisting of aliphatic carboxy group consisting of H. C.20 alkyl, C-2 alkoxy, C-20 late, aromatic carboxylate, Cl, Br, and I. aryl, F, Cl, Br, and I, and Y represents an anionic ligand Selected from the group consisting of aliphatic carboxy 13. A compound represented by the following formula. late, aromatic carboxylate, Cl, Br, and I. 11. A method according to claim 1, wherein the cobalt Schiff base complex is a compound represented by the fol lowing formula.

(

/ NE Ne/ O Bu

Bu O O Bu O RN NHR -s, NR : RN NHR NR: O

O MeO Ph MeO Ph MeO Ph MeO Ph