Enantioselective binding and extraction of zwitterionic amino acids by chiral lanthanide complexes

Tsukube, Hiroshi; Uenishi, Jun’ichi; Kanatani, Tatsuya; Itoh, Hiroyuki; Yonemitsu, Osamu

doi:10.1039/cc9960000477

Cited by 30 publications

(15 citation statements)

References 17 publications

(1 reference statement)

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“…The resulting intrinsic selectivities ranged from 1.8 to 4.5 for non-aromatic a-amino acids. 114 Some chiral lanthanide(III) tris(b-diketonates) are known to act as effective receptors for anionic substrates in solutions and are frequently used as chiral shift reagents in NMR spectroscopy. 115 The negatively charged and highly coordinated complexes can interact and bind the ammonium part of the a-amino acid in an intramolecular fashion via electrostatic interaction (Fig.…”

Section: Metal Complexes and Metalloids As Reactive Extractantsmentioning

confidence: 99%

Chiral separation by enantioselective liquid–liquid extraction

et al. 2011

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The literature on enantioselective liquid-liquid extraction (ELLE) spans more than half a century of research. Nonetheless, a comprehensive overview has not appeared during the past few decades. Enantioselective liquid-liquid extraction is a technology of interest for a wide range of chemists and chemical engineers in the fields of fine chemicals, pharmaceuticals, agrochemicals, fragrances and foods. In this review the principles and advances of resolution through enantioselective liquid-liquid extraction are discussed, starting with an introduction on the principles of enantioselective liquid-liquid extraction including host-guest chemistry, extraction and phase transfer mechanisms, and multistage liquid-liquid extraction processing. Then the literature on enantioselective liquid-liquid extraction systems is reviewed, structured on extractant classes. The following extractant classes are considered: crown ether based extractants, metal complexes and metalloids, extractants based on tartrates, and a final section with all other types of chiral extractants.

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Section: Metal Complexes and Metalloids As Reactive Extractantsmentioning

confidence: 99%

Chiral separation by enantioselective liquid–liquid extraction

et al. 2011

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“…The resulting anionic species can interact with the ammonium moiety of the bound amino acid through electrostatic interaction, so that the parent lanthanide tris^-diketonates) binds the zwitterionic amino acid via two-point binding. Both functional groups of the amino acid are positionally fixed on the lanthanide complex and chiral discrimination is sometime possible (38).…”

Section: Further Applications Of Rare Earth Complexes In Liquid Membrmentioning

confidence: 99%

New Tactics in Design of Ion-Specific Carriers: Approaches Based on Computer Chemistry and Rare Earth Complex Chemistry

Tsukube

1996

ACS Symposium Series

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New approaches for development of specific carriers for use in liquid membrane are described: (i) computer-aided design of cation-specific carriers and (ii) functionalization of rare earth complexes as anion carriers. A new series of Li(I) and Ag(I) ion-specific carriers are successfully designed using MM2, MNDO and density functional calculations. Computer chemistry provides a rational basis for design and characterization of cation-specific carriers of armed crown ether -and podand-types. Lipophilic lanthanide tris(β-diketonates) are shown to be a new class of membrane carriers. They form 1:1 complexes with anionic guests and mediate transport of amino acid derivatives. Since these complexes exhibit different anion transport properties from those of crown ethers, further applications of rare earth complexes offer promising possibilities in the development of specific anion carriers for liquid membrane systems.Liquid membranes incorporating host species can effect rapid and selective transport of a variety of guest species and have wide applications in sensing and separation processes (1). As observed in biomembrane transport systems, host molecules recognize guest species of interest and selectively transport them. Valinomycin is an example of such biological carriers. It specifically mediates biological transport of K(I) cation, but rarely carries other substrates such as organic ammonium cations. In contrast, the synthetic ionophore 18-crown-6 and other crown ethers are known to transport alkali, alkaline earth, heavy and transition metal cations as well as organic substrates. This means that synthetic carriers can mediate artificial transport of various guests, while naturally occurring carriers transport only limited kinds of biological guests such as K(I) cation and biogenetic amines. Since the carrier dramatically improves transport performance, development of new, specific carriers is the most exciting task in liquid membrane science and technology (2,3). This chapter describes new tactics in carrier chemistry which have recently been established in our laboratory. They provide new strategies and concepts in the design of powerful carriers which are specific for some metal cations and organic guests. Our discussion here focuses on (i) computer-aided design of organic carriers specific for Li(I) and Ag(I) cations and (ii) 0097-6156/96A)642-0142$15.00A)

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“…However, the large number of steps often required for their synthesis [182] and, consequently, their cost as well as their limited loadability makes them not very suitable for preparative purposes. Examples of ligand-exchange [193] or anion-exchange selectors [183] able to discriminate amino acid derivatives have also been described.…”

Section: Chiral Extractionsmentioning

confidence: 99%