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Neranon, K., Alberch, L. & Ramström, O. (2020). Design, Synthesis and Self-Assembly of Functional Amphiphilic Metallodendrimers. ChemistryOpen, 9(1), 45-52
Open this publication in new window or tab >>Design, Synthesis and Self-Assembly of Functional Amphiphilic Metallodendrimers
2020 (English)In: ChemistryOpen, ISSN 2191-1363, Vol. 9, no 1, p. 45-52Article in journal (Refereed) Published
Abstract [en]

A new family of alkynylated, amphiphilic dendrimers consisting of amidoamine linkers connected to 5,5 '-functionalized 2,2 '-bipyridine cores has been developed and evaluated in the formation of metallodendrimers of different generations and in self-assembly protocols. A convergent synthetic strategy was applied to provide dumbbell-shaped amphiphilic dendrimers, where the 2,2 '-bipyridine cores could be coordinated to Fe-II centers to afford corresponding metallodendrimers. The ability of the metallic- and non-metallic dendritic structures to self-assemble into functional supramolecular aggregates were furthermore evaluated in aqueous solution. Spherical aggregates with sizes of a few hundred nanometers were generally produced, where controlled disassembly of the metallodendrimers through decomplexation could be achieved.

Place, publisher, year, edition, pages
WILEY-V C H VERLAG GMBH, 2020
Keywords
amphiphiles, metallodendrimers, self-assembly, coordination, nanomaterials, supramolecular systems
National Category
Organic Chemistry
Identifiers
urn:nbn:se:kth:diva-269025 (URN)10.1002/open.201900298 (DOI)000513071200008 ()31921545 (PubMedID)2-s2.0-85079403995 (Scopus ID)
Note

QC 20200312

Available from: 2020-03-12 Created: 2020-03-12 Last updated: 2020-03-12Bibliographically approved
Karalius, A., Zhang, Y., Kravchenko, O., Elofsson, U., Szabo, Z., Yan, M. & Ramström, O. (2020). Formation and Out‐of‐Equilibrium, High/Low State Switching of a Nitroaldol Dynamer in Neutral Aqueous Media. Angewandte Chemie International Edition, 59
Open this publication in new window or tab >>Formation and Out‐of‐Equilibrium, High/Low State Switching of a Nitroaldol Dynamer in Neutral Aqueous Media
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2020 (English)In: Angewandte Chemie International Edition, ISSN 1433-7851, E-ISSN 1521-3773, Vol. 59Article in journal (Refereed) In press
National Category
Organic Chemistry
Identifiers
urn:nbn:se:kth:diva-267001 (URN)10.1002/anie.201911706 (DOI)000508501500001 ()
Note

QC 20200203

Available from: 2020-01-29 Created: 2020-01-29 Last updated: 2020-02-03Bibliographically approved
Xie, S., Zhou, J., Chen, X., Kong, N., Fan, Y., Hammer, G., . . . Yan, M. (2019). A versatile catalyst-free perfluoroaryl azide-aldehyde-amine conjugation reaction. MATERIALS CHEMISTRY FRONTIERS, 3(2), 251-256
Open this publication in new window or tab >>A versatile catalyst-free perfluoroaryl azide-aldehyde-amine conjugation reaction
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2019 (English)In: MATERIALS CHEMISTRY FRONTIERS, ISSN 2052-1537, Vol. 3, no 2, p. 251-256Article in journal (Refereed) Published
Abstract [en]

In a tri-component reaction, an electrophilically-activated perfluoroaryl azide, an enolizable aldehyde and an amine react readily at room temperature without any catalysts in solvents including aqueous conditions to yield a stable amidine conjugate. The versatility of this reaction is demonstrated in the conjugation of an amino acid without prior protection of the carboxyl group, and in the synthesis of antibiotic-nanoparticle conjugates.

Place, publisher, year, edition, pages
ROYAL SOC CHEMISTRY, 2019
National Category
Materials Chemistry
Identifiers
urn:nbn:se:kth:diva-244534 (URN)10.1039/c8qm00516h (DOI)000457644400009 ()2-s2.0-85060918688 (Scopus ID)
Note

QC 20190403

Available from: 2019-04-03 Created: 2019-04-03 Last updated: 2019-12-20Bibliographically approved
Timmer, B. & Ramström, O. (2019). Acid-Assisted Direct Olefin Metathesis of Unprotected Carbohydrates in Water. Chemistry - A European Journal, 25(63), 14408-14413
Open this publication in new window or tab >>Acid-Assisted Direct Olefin Metathesis of Unprotected Carbohydrates in Water
2019 (English)In: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 25, no 63, p. 14408-14413Article in journal (Refereed) Published
Abstract [en]

The ability to use unprotected carbohydrates in olefin metathesis reactions in aqueous media is demonstrated. By using water-soluble, amine-functionalized Hoveyda-Grubbs catalysts under mildly acidic aqueous conditions, the self-metathesis of unprotected alkene-functionalized alpha-d-manno- and alpha-d-galactopyranosides could be achieved through minimization of nonproductive chelation and isomerization. Cross-metathesis with allyl alcohol could also be achieved with reasonable selectivity. The presence of small quantities (2.5 vol %) of acetic acid increased the formation of the self-metathesis product while significantly reducing the alkene isomerization process. The catalytic activity was furthermore retained in the presence of large amounts (0.01 mm) of protein, underlining the potential of this carbon-carbon bond-forming reaction under biological conditions. These results demonstrate the potential of directly using unprotected carbohydrate structures in olefin metathesis reactions under mild conditions compatible with biological systems, and thereby enabling their use in, for example, drug discovery and protein derivatization.

Place, publisher, year, edition, pages
WILEY-V C H VERLAG GMBH, 2019
Keywords
carbene ligands, carbohydrates, homogeneous catalysis, olefin metathesis, synthetic methods
National Category
Organic Chemistry
Identifiers
urn:nbn:se:kth:diva-264872 (URN)10.1002/chem.201903155 (DOI)000496034100021 ()31390489 (PubMedID)2-s2.0-85074340512 (Scopus ID)
Note

QC 20191217

Available from: 2019-12-17 Created: 2019-12-17 Last updated: 2019-12-17Bibliographically approved
Zhang, Y., Xie, S., Yan, M. & Ramström, O. (2019). Enzyme- and ruthenium-catalyzed dynamic kinetic resolution involving cascade alkoxycarbonylations for asymmetric synthesis of 5-Substituted N-Aryloxazolidinones. Molecular Catalysis, 470, 138-144
Open this publication in new window or tab >>Enzyme- and ruthenium-catalyzed dynamic kinetic resolution involving cascade alkoxycarbonylations for asymmetric synthesis of 5-Substituted N-Aryloxazolidinones
2019 (English)In: Molecular Catalysis, ISSN 2468-8231, Vol. 470, p. 138-144Article in journal (Refereed) Published
Abstract [en]

AAsymmetric synthesis of N-aryloxazolidinones via dynamic kinetic resolution was developed. A ruthenium-based catalyst was used in the racemization of beta-anilino alcohols, while Candida antarctica lipase B (CAL-B) was applied for two selective alkoxycarbonylations operating in cascade. Various N-aryloxazolidinone derivatives were obtained in high yields and good enantiopurities.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Asymmetric synthesis, Candida Antarctica lipase B, Cascade alkoxycarbonylation, Dynamic kinetic resolution, Oxazolidinone, Candida, Isomers, Ruthenium, Yeast, Alkoxycarbonylation, Oxazolidinones, Kinetics
National Category
Organic Chemistry
Identifiers
urn:nbn:se:kth:diva-252525 (URN)10.1016/j.mcat.2019.03.020 (DOI)000469906600017 ()2-s2.0-85063965626 (Scopus ID)
Note

QC 20190613

Available from: 2019-06-13 Created: 2019-06-13 Last updated: 2019-12-20Bibliographically approved
Xie, S., Manuguri, S., Ramström, O. & Yan, M. (2019). Impact of Hydrogen Bonding on the Fluorescence of N-Amidinated Fluoroquinolone. Chemistry - An Asian Journal, 14(6), 910-916
Open this publication in new window or tab >>Impact of Hydrogen Bonding on the Fluorescence of N-Amidinated Fluoroquinolone
2019 (English)In: Chemistry - An Asian Journal, ISSN 1861-4728, E-ISSN 1861-471X, Vol. 14, no 6, p. 910-916Article in journal (Refereed) Published
Abstract [en]

The fluorescence properties of AIE-active N-amidinated fluoroquinolones, efficiently obtained by a perfluoroaryl azide-aldehyde-amine reaction, have been studied. The fluorophores were discovered to elicit a highly sensitive fluorescence quenching response towards guest molecules with hydrogen-bond-donating ability. This effect was evaluated in a range of protic/aprotic solvents with different H-bonding capabilities, and also in aqueous media. The influence of acid/base was furthermore addressed. The hydrogen-bonding interactions were studied by IR, NMR, UV/Vis and time-resolved fluorescence decay, revealing their roles in quenching of the fluorescence emission. Due to the pronounced quenching property of water, the N-amidinated fluoroquinolones could be utilized as fluorescent probes for quantifying trace amount of water in organic solvents.

Place, publisher, year, edition, pages
Wiley-VCH Verlagsgesellschaft, 2019
Keywords
aggregation-induced emission, fluorescence quenching, fluoroquinolones, hydrogen bonds, water sensors
National Category
Organic Chemistry
Identifiers
urn:nbn:se:kth:diva-248338 (URN)10.1002/asia.201801916 (DOI)000461836500032 ()30762939 (PubMedID)2-s2.0-85062327816 (Scopus ID)
Note

QC 20190408

Available from: 2019-04-08 Created: 2019-04-08 Last updated: 2019-12-20Bibliographically approved
Ren, Y., Hu, L. & Ramström, O. (2019). Multienzymatic cascade synthesis of an enantiopure (2R,5R)-1,3-oxathiolane anti-HIV agent precursor. Molecular Catalysis, 468, 52-56
Open this publication in new window or tab >>Multienzymatic cascade synthesis of an enantiopure (2R,5R)-1,3-oxathiolane anti-HIV agent precursor
2019 (English)In: Molecular Catalysis, ISSN 2468-8231, Vol. 468, p. 52-56Article in journal (Refereed) Published
Abstract [en]

An enantiopure (2R,5R)-1,3-oxathiolane was obtained using a multienzymatic cascade protocol. By employing a combination of surfactant-treated subtilisin Carlsberg and Candida antarctica lipase B, the absolute configuration of the resulting 1,3-oxathiolane ring was efficiently controlled, resulting in an excellent enantiomeric excess (>99%). This enantiopure 1,3-oxathiolane derivative is a key precursor to anti-HIV agents, such as lamivudine, through subsequent N-glycosylation.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
1, 3-Oxathiolane, Candida antarctica lipase B, Enzyme, HIV, Subtilisin Carlsberg
National Category
Chemical Sciences
Identifiers
urn:nbn:se:kth:diva-246434 (URN)10.1016/j.mcat.2019.02.013 (DOI)000463293300007 ()2-s2.0-85061747406 (Scopus ID)
Note

QC 20190329

Available from: 2019-03-29 Created: 2019-03-29 Last updated: 2019-12-20Bibliographically approved
Xie, S., Proietti, G., Ramström, O. & Yan, M. (2019). Photoactivatable Fluorogens by Intramolecular C-H Insertion of Perfluoroaryl Azide. Journal of Organic Chemistry, 84(22), 14520-14528
Open this publication in new window or tab >>Photoactivatable Fluorogens by Intramolecular C-H Insertion of Perfluoroaryl Azide
2019 (English)In: Journal of Organic Chemistry, ISSN 0022-3263, E-ISSN 1520-6904, Vol. 84, no 22, p. 14520-14528Article in journal (Refereed) Published
Abstract [en]

Molecules, capable of fluorescence turn-on by light, are highly sought-after in spatio-temporal labeling, surface patterning, monitoring cellular and molecular events, and high-resolution fluorescence imaging. In this work, we report a fluorescence turn-on system based on photoinitiated intramolecular C-H insertion of azide into the neighboring aromatic ring. The azide-masked fluorogens were efficiently synthesized via a cascade nucleophilic aromatic substitution of perfluoroaryl azides with carbazoles. The scaffold also allows for derivatization with biological ligands, as exemplified with D-mannose in this study. This photoinitiated intramolecular transformation led to high yields, high photo-conversion efficiency, and well-separated wavelengths for photoactivation and fluorescence excitation. The mannose-derivatized structure enabled spatio-temporal activation and showed high contrast and signal amplification. Live cell imaging suggested that the mannose-tagged fluorogen was transported to the lysosomes.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2019
National Category
Chemical Sciences
Identifiers
urn:nbn:se:kth:diva-269136 (URN)10.1021/acs.joc.9b02050 (DOI)000497259900015 ()31589042 (PubMedID)2-s2.0-85074604850 (Scopus ID)
Note

QC 20200312

Available from: 2020-03-12 Created: 2020-03-12 Last updated: 2020-03-28Bibliographically approved
Abellan-Flos, M., Timmer, B. J. J., Altun, S., Aastrup, T., Vincent, S. P. & Ramström, O. (2019). QCM sensing of multivalent interactions between lectins and well-defined glycosylated nanoplatforms. Biosensors & bioelectronics, 139, Article ID 111328.
Open this publication in new window or tab >>QCM sensing of multivalent interactions between lectins and well-defined glycosylated nanoplatforms
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2019 (English)In: Biosensors & bioelectronics, ISSN 0956-5663, E-ISSN 1873-4235, Vol. 139, article id 111328Article in journal (Refereed) Published
Abstract [en]

Quartz crystal microbalance (QCM) methodology has been adopted to unravel important factors contributing to the "cluster glycoside effect" observed in carbohydrate-lectin interactions. Well-defined, glycosylated nanostructures of precise sizes, geometries and functionalization patterns were designed and synthesized, and applied to analysis of the interaction kinetics and thermodynamics with immobilized lectins. The nanostructures were based on Borromean rings, dodecaamine cages, and fullerenes, each of which carrying a defined number of carbohydrate ligands at precise locations. The synthesis of the Borromeates and dodecaamine cages was easily adjustable due to the modular assembly of the structures, resulting in variations in presentation mode. The binding properties of the glycosylated nanoplatforms were evaluated using flow-through QCM technology, as well as hemagglutination inhibition assays, and compared with dodecaglycosylated fullerenes and a monovalent reference. With the QCM setup, the association and dissociation rate constants and the associated equilibrium constants of the interactions could be estimated, and the results used to delineate the multivalency effects of the lectin-nanostructure interactions.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
QCM, Carbohydrates, Lectins, Multivalency, Nanoplatforms
National Category
Organic Chemistry
Identifiers
urn:nbn:se:kth:diva-255296 (URN)10.1016/j.bios.2019.111328 (DOI)000472696000013 ()31136921 (PubMedID)2-s2.0-85066129421 (Scopus ID)
Note

QC 20190730

Available from: 2019-07-30 Created: 2019-07-30 Last updated: 2019-12-20Bibliographically approved
Ren, Y., Svensson, P. H. & Ramström, O. (2018). A Multicontrolled Enamine Configurational Switch Undergoing Dynamic Constitutional Exchange. Angewandte Chemie International Edition, 57(21), 6256-6260
Open this publication in new window or tab >>A Multicontrolled Enamine Configurational Switch Undergoing Dynamic Constitutional Exchange
2018 (English)In: Angewandte Chemie International Edition, ISSN 1433-7851, E-ISSN 1521-3773, Vol. 57, no 21, p. 6256-6260Article in journal (Refereed) Published
Abstract [en]

A multiresponsive enamine-based molecular switch is presented, in which forward/backward configurational rotation around the C=C bond could be precisely controlled by the addition of an acid/base or metal ions. Fluorescence turn-on/off effects and large Stokes shifts were observed while regulating the switching process with Cu-II. The enamine functionality furthermore enabled double dynamic regimes, in which configurational switching could operate in conjunction with constitutional enamine exchange of the rotor part. This behavior was used to construct a prototypical dynamic covalent switch system through enamine exchange with primary amines. The dynamic exchange process could be readily turned on/off by regulating the switch status with pH.

Place, publisher, year, edition, pages
WILEY-V C H VERLAG GMBH, 2018
Keywords
dynamic exchange, enamines, fluorescence, E/Z isomerization, molecular switches
National Category
Physical Chemistry
Identifiers
urn:nbn:se:kth:diva-230434 (URN)10.1002/anie.201802994 (DOI)000432710100049 ()29601656 (PubMedID)2-s2.0-85046299449 (Scopus ID)
Note

QC 20180615

Available from: 2018-06-15 Created: 2018-06-15 Last updated: 2019-12-20Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-1533-6514

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