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

doi:10.1016/j.tetasy.2003.09.018

Cited by 46 publications

(18 citation statements)

References 7 publications

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“…[58] This substrate was suspected to undergo chlorine-catalyzed racemization that can be promoted in the presence of Co IIIsalen species. [59][60][61] Therefore, supported Co-salen catalysts are advantageous, because the catalysts can readily be removed from the reaction mixture after the HKR. [42] Prior to the catalytic reaction, Co II precatalysts 5 a-e were oxidized to the corresponding Co III active species in the open air with the help of excessive acetic acid.…”

Section: Metallation Of Salen Polymers With Cobalt(ii) Acetatementioning

confidence: 99%

Poly(styrene)‐Supported Co–Salen Complexes as Efficient Recyclable Catalysts for the Hydrolytic Kinetic Resolution of Epichlorohydrin

Zheng

Jones

Weck

2005

Chemistry A European J

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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.

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Section: Metallation Of Salen Polymers With Cobalt(ii) Acetatementioning

confidence: 99%

Poly(styrene)‐Supported Co–Salen Complexes as Efficient Recyclable Catalysts for the Hydrolytic Kinetic Resolution of Epichlorohydrin

Zheng

Jones

Weck

2005

Chemistry A European J

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“…1,2 The attractive features of the HKR include: high selectivity factors (k rel values) across a wide range of terminal epoxides, allowing access to highly enantioenriched (>99% ee) products in close to theoretical yields; a practical (and scaleable) 3 reaction protocol involving a commercially available catalyst; ready accessibility at low cost of a wide variety of terminal epoxides in racemic form; and absence of useful alternative approaches to the preparation of enantiopure terminal epoxides. 4 However, despite the relatively low catalyst loadings used in HKR reactions (0.2-2 mol%) and demonstrated catalyst recycleability with key substrates, 2,5 the principal cost determinant in the HKR remains the catalyst.…”

Section: Introductionmentioning

confidence: 99%

New oligomeric catalyst for the hydrolytic kinetic resolution of terminal epoxides under solvent-free conditions

White

Jacobsen

2003

Tetrahedron: Asymmetry

102

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“…In HKR of styrene oxide, CoB3 showed distinguished major configurations for two resolution products due to (S,S)-configuration of Co-salen at homogeneous level (entries 15 vs. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] [41]. Particularly, HB6 showed two major configurations contrary to CoB3 (entries 20 vs. 15).…”

Section: Catalytic Hydrolytic Kinetic Resolution Of Epoxidesmentioning

confidence: 99%

Macroporous Helical Silica Immobilizing Cobalt-Salen Complex Catalyzed Asymmetric Hydrolytic Kinetic Resolution of Epoxides

Huang

Liu

et al. 2015

Catal Surv Asia

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Based on an entropy-driven principle, new macroporous helical silica rods were synthesized by using mild templates in sol-gel, then functionalized for immobilizing Co-salen complexes to catalyze enantioselective hydrolytic kinetic resolution of epoxides. Characterization revealed both silica supports and heterogeneous Co-salen complexes were macroporous helical materials with affirmative chirality. Catalysis revealed enantioselective adsorption of substrate on silica supports dominated major configuration of resolution products rather than configuration of Co-salen. The (S)-amino alcohol-doped silica and Co-(R,R)salen comprised the most enantioselective combination, which proved chiral synergy between support and Co-salen did exist. This work would contribute to the design of new support materials for asymmetric catalysis.

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Commercialization of the hydrolytic kinetic resolution of racemic epoxides: toward the economical large-scale production of enantiopure epichlorohydrin

Cited by 46 publications

References 7 publications

Poly(styrene)‐Supported Co–Salen Complexes as Efficient Recyclable Catalysts for the Hydrolytic Kinetic Resolution of Epichlorohydrin

Poly(styrene)‐Supported Co–Salen Complexes as Efficient Recyclable Catalysts for the Hydrolytic Kinetic Resolution of Epichlorohydrin

New oligomeric catalyst for the hydrolytic kinetic resolution of terminal epoxides under solvent-free conditions

Macroporous Helical Silica Immobilizing Cobalt-Salen Complex Catalyzed Asymmetric Hydrolytic Kinetic Resolution of Epoxides

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