13403-37-7Relevant academic research and scientific papers
Commercialization of the hydrolytic kinetic resolution of racemic epoxides: Toward the economical large-scale production of enantiopure epichlorohydrin
Larrow, Jay F.,Hemberger, Karl E.,Jasmin, Serge,Kabir, Hocine,Morel, Phillipe
, p. 3589 - 3592 (2003)
The hydrolytic kinetic resolution of racemic terminal epoxides utilizing chiral (salen)Co(III) catalysts provides practical access to enantiopure epoxides and diols. However, general issues surrounding catalyst activation combined with the specific problem of racemization of epichlorohydrin served to make the large-scale production of (R)- or (S)-epichlorohydrin difficult and uneconomical. A process for the large-scale production and isolation of active (salen)Co(III)OAc catalyst and a method of catalyst reduction after reaction using ascorbic acid have been developed to overcome these issues.
Homochiral Metal-Organic Cage for Gas Chromatographic Separations
Xie, Sheng-Ming,Fu, Nan,Li, Li,Yuan, Bao-Yan,Zhang, Jun-Hui,Li, Yan-Xia,Yuan, Li-Ming
, p. 9182 - 9188 (2018)
Metal-organic cages (MOCs) as a new type of porous material with well-defined cavities were extensively pursued because of their relative ease of synthesis and their potential applications in host-guest chemistry, molecular recognition, separation, catalysis, gas storage, and drug delivery. Here, we first reported that a homochiral MOC [Zn3L2] is explored to fabricate [Zn3L2] coated capillary column for high-resolution gas chromatographic separation of a wide range of analytes, including n-alkanes, polycyclic aromatic hydrocarbons, and positional isomers, especially for racemates. Various kinds of racemates such as alcohols, diols, epoxides, ethers, halohydrocarbons, and esters were separated with good enantioselectivity and reproducibility on the [Zn3L2] coated capillary column. The fabricated [Zn3L2] coated capillary column exhibited significant chiral recognition complementary to that of a commercial β-DEX 120 column and our recently reported homochiral porous organic cage CC3-R coated column. The results show that the homochiral MOCs will be very attractive as a new type of chiral selector in separation science.
ASYMMETRIC CYCLIZATIONS OF SOME CHLOROHYDRINS CATALYZED BY OPTICALLY ACTIVE COBALT (SALEN) TYPE COMPLEXES
Takfichi, Tsutomu,Arihara, Motoji,,Ishimori, Michihiro,Tsuruta, Teiji
, p. 3391 - 3398 (1980)
Optically active chloromethyloxirane was obtained from 1,3-dichloro-2-propanol by a process of asymmetric synthesis.The highest enantiomeric excess (e.e.) of chloromethyloxirane that could be obtained was 67percent, using Co(II) (3,5-Cl,Cl-sal)2(S-CHXDA) and K2CO3 as the catalyst and base, respectively.For purpose of comparison, asymmetric cyclizations of racemic 2,3-dichloro-1-propanol and 2-chloro-1-propanol were examined; optically active chloromethyloxirane and methyloxyrane were obtained according to kinetic resolution mechanisms, although the optical purities of oxiranes formed were not so high.The mechanisms for the asymmetric reactions were investigated by circular dichroism and absorption spectroscopies.It was found that the cobalt (salen) type complex forms a new complex with alkali metal carbonate, similarly to the function of crown ether.The substrate interacts with the newly formed chiral complex, followed by cyclization to give optically active oxiranes.
Synthesis of carbon monolith with bimodal meso/macroscopic pore structure and its application in asymmetric catalysis
Kim, Yong-Suk,Guo, Xiao-Feng,Kim, Geon-Joong
, p. 91 - 99 (2010)
Carbon monolith with bimodal meso/macroporous pore structures was synthesized by the nanocasting method, using corresponding monolith silica as templates. The pore system of this material was characterized by instrumental analysis. The adjacent macropores are interconnected through uniform-sized windows, and the walls of macrospheres consist of mesostructured pores. Chiral Co(III)-(BF3) salen immobilized on a meso/macroporous carbon monolith can be applied as an effective heterogeneous catalyst for an asymmetric reaction such as a hydrolytic kinetic reaction of terminal epoxides. The catalysts were prepared with different loading amounts of aluminium chloride to anchor the active salen complex, and the catalytic activity increased with increasing amount of aluminum chloride on the surfaces, showing up to 99 ee% of the product epichlorohydrin (ECH).
Synthesis of chiral epichlorohydrin by chloroperoxidase-catalyzed epoxidation of 3-chloropropene in the presence of an ionic liquid as co-solvent
Wu, Jinyue,Liu, Chen,Jiang, Yucheng,Hu, Mancheng,Li, Shuni,Zhai, Quanguo
, p. 727 - 731 (2010)
Asymmetric epoxidation of 3-chloropropene can be catalyzed by chloroperoxidase (CPO) from Caldariomyces fumago to prepare (R)-epichlorohydrin (ECH) in homogenous phosphate buffer/ionic liquid mixtures using t-butyl hydroperoxide (TBHP) as O2 donor. Reaction conditions were optimized by the investigation of the choice of oxidants, the presence of ionic liquids (ILs), pH effect and CPO consumption. The best ECH yield reached 88.8% within a duration of 60 min with high enantiomeric excesses (e.e. 97.1%) at pH 5.5 and room temperature, using 1-ethyl-3-methylimidazolium [EMIM][Br] as co-solvent. The ILs with shorter carbon chain was more efficient on chiral ECH preparation.
Molecular modification of a halohydrin dehalogenase for kinetic regulation to synthesize optically pure (S)-epichlorohydrin
Zhang, Xiao-Jian,Deng, Han-Zhong,Liu, Nan,Gong, Yi-Chuan,Liu, Zhi-Qiang,Zheng, Yu-Guo
, p. 154 - 160 (2019)
Asymmetric synthesis of chiral epichlorohydrin (ECH) from 1,3-dichloro-2-propanol (1,3-DCP) using halohydrin dehalogenases (HHDHs) is of great value due to the 100% theoretical yield and high enantioselectivity. The vital problem in the asymmetric synthesis is to prepare optically pure ECH. In this study, key amino acid residues located at halide ion channels of HheC (P175S/W249P) (HheCPS) were modified to regulate the kinetic parameters. HheCPS I81W, F86N and V94R were constructed with the corresponding halide ion channels destroyed. The catalytically efficiencies (kcat/Km) of the three mutants exhibited 0.38-, 0.23- and 0.23-fold decrease toward (S)-ECH and the reverse reaction was significantly inhibited. As the results, (S)-ECH was synthesized with >99% enantiomeric excess (e.e.) and 63.42%, 67.08% and 57.01% yields, respectively, under 20 mM 1,3-DCP as substrate. To our knowledge, this is the first investigation of the molecule kinetic modification of HHDHs and also the first report for the biosynthesis of optically pure (S)-ECH from 1,3-DCP using HHDHs.
Novel highly active polymer supported chiral Co(III)-salen catalysts for hydrolytic kinetic resolution of epichlorohydrin
Matkiewicz, Katarzyna,Bukowska, Agnieszka,Bukowski, Wiktor
, p. 43 - 52 (2013)
A series of novel polymer supported chiral Co(III)-salen catalysts based on the hydroxyl functionalized gel-type resins, the HEMA resins, has been developed. The terpolymers used as supports for the immobilization of the salen catalysts were derived from the mixtures of 2-hydroxyethyl methacrylate (HEMA), styrene and different divinyl monomers (divinylbenzene, diethylene and triethylene glycol dimethacrylates, 1,4-butanediol and 1,6-hexanediol dimethacrylates). It was found that the novel catalysts show the high catalytic activity in the hydrolytic kinetic resolution (HKR) of rac-epichlorohydrin in the medium of THF, TBME, CH2Cl2 and CH3CN. tert-Butyl methyl ether appeared to be the best medium for performing the resolution. An effect of the nature of the polymer matrices on activity of the supported catalysts was also observed. The activity could be improved by optimization of HEMA concentration in the mixture of the monomers and by selection of the cross-linker. The most active catalyst was prepared based on the HEMA resin derived form 30 mol.% of HEMA and diethylene glycol dimethacrylate as a cross-linker. In the presence of this catalyst the HKR could be performed even at 0.01 mol.% concentration of Co(III) ions. The catalysts could be recycled 10th time at 0.5 mol.% concentration without any additional reactivation. It allowed conducting the HKR of epichlorohydrin within less than 60 min even in the 10th cycle. The catalyst with the highest loading of catalytic centers could be also used successfully for conducting the HKR of epichlorohydrin in solvent-free conditions. Its activity can be compared to the most active heterogeneous catalyst of the HKR described to date.
Factors influencing recyclability of Co(III)-salen catalysts in the hydrolytic kinetic resolution of epichlorohydrin
Jain, Surbhi,Venkatasubbaiah, Krishnan,Jones, Christopher W.,Davis, Robert J.
, p. 8 - 15 (2010)
The recyclability of Co(III)-salen catalysts, where salen is defined by (R,R)-N,N′-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine, for the hydrolytic kinetic resolution (HKR) of racemic epichlorohydrin is a strong function of the counterion of the Co(III)-salen catalyst. The nature of the counterion determines whether the HKR reaction follows primarily a bimetallic or monometallic reaction path, which significantly affects catalyst recyclability. For example, Co(III)-salen initially containing the nucleophilic Cl- counterion catalyzes the HKR of epichlorohydrin according to a bimetallic reaction path but loses activity upon recycle, as Cl- is replaced with OH- during the reaction. In contrast, a Co(III)-salen catalyst containing non-nucleophilic SbF6- counterion catalyzes the reaction according to a monometallic reaction path and is quite stable during multiple recycles, albeit at a low rate with less selectivity. A mixed catalyst system with Co(III)-salen initially containing Cl- to which Co(III)-salen with SbF6- is later added demonstrates high activity and high stability to recycling. Additional experiments with Co(III)-salen initially containing the acetate counterion reveal a progressive decline in activity with multiple recycles even after regeneration with acetic acid between runs, suggesting a destructive role of the regeneration process.
Distannoxane-catalyzed selective acetylation of 3-chloropropane-1,2- diol: A convenient synthesis of enantiopure epichlorohydrin
Orita, Akihiro,Ito, Toshihide,Yasui, Yutaka,Otera, Junzo
, p. 1927 - 1929 (1999)
A distannoxane catalyst effects exclusive acetylation of the primary alcohol of 3-chloropropane-1,2-diol. This reaction provides a convenient access to enantiopure epichlorohydrin.
Poly(styrene)-supported co-salen complexes as efficient recyclable catalysts for the hydrolytic kinetic resolution of epichlorohydrin
Zheng, Xiaolai,Jones, Christopher W.,Weck, Marcus
, p. 576 - 583 (2006)
Here we describe an unprecedented synthetic approach to poly-(styrene)-supported chiral salen ligands by the free radical polymerization of an unsymmetrical styryl-substituted salen monomer (H2salen = bis(salicylidene)ethylenediamine). The new method allows for the attachment of salen moieties to the polymer main chain in a flexible, pendant fashion, avoiding grafting reactions that often introduce ill-defined species on the polymers. Moreover, the loading of the salen is controlled by the copolymerization of the styryl-substituted salen monomer with styrene in different ratios. The polymeric salen ligands are metallated with cobalt(II) acetate to afford the corresponding supported Co-salen complexes, which are used in the hydrolytic kinetic resolution of racemic epichlorohydrin, exhibiting high reactivity and enantioselectivity. Remarkably, the copolymer-supported Co-salen complexes showed a better catalytic performance (>99% ee, 54 % conversion, one hour) in comparison to the homopolymeric analogues and the small molecule Co-salen complex. The soluble poly(styrene)-supported catalysts were recovered by precipitation after the catalytic reactions and were recycled three times to afford almost identical enantiomeric excesses as the first run, with slightly reduced reaction rates.
