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Akkarasamiyo, S., Sawadjoon, S., Orthaber, A. & Samec, J. S. M. (2018). Tsuji-Trost Reaction of Non-Derivatized Allylic Alcohols. Chemistry - A European Journal, 24(14), 3488-3498
Open this publication in new window or tab >>Tsuji-Trost Reaction of Non-Derivatized Allylic Alcohols
2018 (English)In: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 24, no 14, p. 3488-3498Article in journal (Refereed) Published
Abstract [en]

Palladium-catalyzed allylic substitution of non-derivatized enantioenriched allylic alcohols with a variety of uncharged N-, S-, C- and O-centered nucleophiles using a bidentate BiPhePhos ligand is described. A remarkable effect of the counter ion (X) of the XPd[kappa(2)-BiPhePhos][kappa(3)-C3H5] was observed. When ClPd[kappa(2)-BiPhePhos][eta(3)-C3H5] (complexI) was used as catalyst, non-reproducible results were obtained. Study of the complex by X-ray crystallography, (PNMR)-P-31 spectroscopy, and ESI-MS showed that a decomposition occurred where one of the phosphite ligands was oxidized to the corresponding phosphate, generating ClPd[kappa(1)-BiPhePhosphite-phosphate][eta(3)-C3H5] species (complexII). When the chloride was exchanged to the weaker coordinating OTf- counter ion the more stable Pd[kappa(2)-BiPhePhos][eta(3)-C3H5](+)+[OTf] (-) (complexIII) was formed. ComplexIII performed better and gave higher enantiospecificities in the substitution reactions. ComplexIII was evaluated in Tsuji-Trost reactions of stereogenic non-derivatized allylic alcohols. The desired products were obtained in good to excellent yields (71-98%) and enantiospecificities (73-99%) for both inter- and intramolecular substitution reactions with only water generated as a by-product. The methodology was applied to key steps in total synthesis of (S)-cuspareine and (+)-lentiginosine. A reaction mechanism involving a palladium hydride as a key intermediate in the activation of the hydroxyl group is proposed in the overall transformation.

Keywords
asymmetric catalysis, cuspareine, OH activation, palladium, Tsuji-Trost reaction
National Category
Organic Chemistry
Identifiers
urn:nbn:se:uu:diva-350623 (URN)10.1002/chem.201705164 (DOI)000426764400020 ()29178406 (PubMedID)
Available from: 2018-05-22 Created: 2018-05-22 Last updated: 2018-05-22Bibliographically approved
Calard, F., Wani, I. H., Hayat, A., Jarrosson, T., Lere-Porte, J.-P., Jafri, S. H., . . . Orthaber, A. (2017). Designing sterically demanding thiolate coated AuNPs for electrical characterization of BPDT in a NP-molecule-nanoelectrode platform. MOLECULAR SYSTEMS DESIGN & ENGINEERING, 2(2), 133-139
Open this publication in new window or tab >>Designing sterically demanding thiolate coated AuNPs for electrical characterization of BPDT in a NP-molecule-nanoelectrode platform
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2017 (English)In: MOLECULAR SYSTEMS DESIGN & ENGINEERING, ISSN 2058-9689, Vol. 2, no 2, p. 133-139Article in journal (Refereed) Published
Abstract [en]

Molecular electronics with single or few molecules requires a stable metal-molecule nanojunction platform. Herein, we report the design and synthesis of gold nanoparticles coated with sterically demanding thiol ligands that are essential to fabricate a versatile and stable nanoelectrode-molecule-nanoparticle platform suitable for electrical characterization of small organic molecules. By combining.-tetraphenylmethane ether functionalized alkyl thioacetate and alkyl thiols, we prepared highly stable gold nanoparticles in a one-phase reaction providing simple and efficient purification. This robust preparation gives highly pure nanoparticles in very high yields (up to 90%) with long-time shelf stability. The synthesis in this work has superior reproducibility compared to previous synthesis processes that are currently being used for such molecular electronics platforms. Electron microscopy confirms the formation of uniform and small nanoparticles in the range of 5 to 7 nm. These nanoparticles with different ligand surface coverages were placed in a 20 nm nanoelectrode setup using dielectrophoretic forces. This setup was utilized to characterize the conductivity of the molecular wire 4,4'-biphenyldithiol introduced via ligand placeexchange under ambient conditions.

Place, publisher, year, edition, pages
ROYAL SOC CHEMISTRY, 2017
National Category
Engineering and Technology
Identifiers
urn:nbn:se:uu:diva-323512 (URN)10.1039/c6me00095a (DOI)000400987200003 ()
Available from: 2017-06-14 Created: 2017-06-14 Last updated: 2018-04-12Bibliographically approved
Blunder, M., Orthaber, A., Bauer, R., Bucar, F. & Kunert, O. (2017). Efficient identification of flavones, flavanones and their glycosides in routine analysis via off-line combination of sensitive NMR and HPLC experiments. Food Chemistry, 218, 600-609
Open this publication in new window or tab >>Efficient identification of flavones, flavanones and their glycosides in routine analysis via off-line combination of sensitive NMR and HPLC experiments
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2017 (English)In: Food Chemistry, ISSN 0308-8146, E-ISSN 1873-7072, Vol. 218, p. 600-609Article in journal (Refereed) Published
Abstract [en]

We present a standardized, straightforward and efficient approach applicable in routine analysis of flavonoids combining sensitive NMR and HPLC experiments. The determination of the relative configuration of sugar moieties usually requires the acquisition of 13C NMR shift values. We use a combination of HPLC and sensitive NMR experiments (1D-proton, 2D-HSQC) for the unique identification of known flavones, flavanones, flavonols and their glycosides. Owing to their broad range of polarity, we developed HPLC and UHPLC methods (H2O/MeOH/MeCN/HCOOH) which we applied and validated by analyzing 46 common flavones and flavanones and exemplified for four plant extracts. A searchable data base is provided with full data comprising complete proton and carbon resonance assignments, expansions of HSQC-spectra, HPLC parameters (retention time, relative retention factor), UV/Vis and mass spectral data of all compounds, which enables a rapid identification and routine analysis of flavones and flavanones from plant extracts and other products in nutrition and food chemistry.

Keywords
NMR, Flavones, Flavanones, HPLC, MS, Data base
National Category
Analytical Chemistry
Identifiers
urn:nbn:se:uu:diva-306576 (URN)10.1016/j.foodchem.2016.09.077 (DOI)000386409700078 ()27719955 (PubMedID)
Available from: 2016-10-28 Created: 2016-10-28 Last updated: 2017-12-28Bibliographically approved
Morales Salazar, D., Mijangos, E., Pullen, S., Gao, M. & Orthaber, A. (2017). Functional small-molecules & polymers containing P[double bond, length as m-dash]C and As[double bond, length as m-dash]C bonds as hybrid π-conjugated materials. Chemical Communications, 53(6), 1120-1123
Open this publication in new window or tab >>Functional small-molecules & polymers containing P[double bond, length as m-dash]C and As[double bond, length as m-dash]C bonds as hybrid π-conjugated materials
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2017 (English)In: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, Vol. 53, no 6, p. 1120-1123Article in journal (Refereed) Published
Abstract [en]

Stable phospha- and arsaalkenes were used to synthesize polymers containing unsaturated P[double bond, length as m-dash]C and As[double bond, length as m-dash]C moieties. The composition, chemical environment, structure, optical, and electronic properties of the monomers and polymers were elucidated. The incorporation of the heteroatom-carbon double bonded units efficiently perturbs the optoelectronics and solid state features of both monomeric and polymeric scaffolds. Proof-of principle work supports their responsive character through post-functionalisation and electrochromic behaviour. To the best of our knowledge, this is the first example of a polymer containing arsenic-carbon double bonds.

National Category
Organic Chemistry Inorganic Chemistry
Identifiers
urn:nbn:se:uu:diva-312610 (URN)10.1039/c6cc08736a (DOI)000393978300026 ()28054056 (PubMedID)
Funder
Lars Hierta Memorial FoundationStiftelsen Olle Engkvist ByggmästareSwedish Research Council, 2013-4763
Available from: 2017-01-12 Created: 2017-01-12 Last updated: 2017-11-29Bibliographically approved
Xiong, R., Bornhof, A.-B., Arkhypchuk, A., Orthaber, A. & Borbas, E. (2017). Furan- and Thiophene-Based Auxochromes Red-shift Chlorin Absorptions and Enable Oxidative Chlorin Polymerizations. Chemistry - A European Journal, 23(17), 4089-4095
Open this publication in new window or tab >>Furan- and Thiophene-Based Auxochromes Red-shift Chlorin Absorptions and Enable Oxidative Chlorin Polymerizations
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2017 (English)In: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 23, no 17, p. 4089-4095Article in journal (Refereed) Published
Abstract [en]

The de novo syntheses of chemically stable chlorins with five-membered heterocyclic (furane, thiophene, formylfurane and formylthiophene) substituents in selected meso- and beta-positions are reported. Heterocycle incorporation in the 3- and 13-positions shifted the chlorin absorption and emission to the red (up to lambdaem =680 nm), thus these readily incorporated substituents function analogously to auxochromes present in chlorophylls, for example, formyl and vinyl groups. Photophysical, theoretical and X-ray crystallographic experiments revealed small but significant differences between the behavior of the furan- and the thiophene-based auxochromes. Four regioisomeric bis-thienylchlorins (3,10; 3,13, 3,15 and 10,15) were oxidatively electropolymerized; the chlorin monomer geometry had a profound impact on the polymerization efficiency and the electrochemical properties of the resulting material. Chemical co-polymerization of 3,13-bis-thienylchlorin with 3-hexylthiophene yielded an organic-soluble red-emitting polymer.

Keywords
chlorins, electrochemistry, photophysics, polymerization, porphyrinoids
National Category
Organic Chemistry
Research subject
Chemistry with specialization in Organic Chemistry
Identifiers
urn:nbn:se:uu:diva-317978 (URN)10.1002/chem.201604655 (DOI)000399312700011 ()27859811 (PubMedID)
Funder
Stiftelsen Olle Engkvist ByggmästareSwedish Research Council, 2013-4655Swedish Research Council, 2013-4763
Available from: 2017-03-22 Created: 2017-03-22 Last updated: 2017-12-28Bibliographically approved
Gupta, A. K., Akkarasamiyo, S. & Orthaber, A. (2017). Rich Coordination Chemistry of pi-Acceptor Dibenzoarsole Ligands. Inorganic Chemistry, 56(8), 4504-4511
Open this publication in new window or tab >>Rich Coordination Chemistry of pi-Acceptor Dibenzoarsole Ligands
2017 (English)In: Inorganic Chemistry, ISSN 0020-1669, E-ISSN 1520-510X, Vol. 56, no 8, p. 4504-4511Article in journal (Refereed) Published
Abstract [en]

A series of dibenzoarsole (also known as 9-arsafluorene) derivatives have been prepared, and their coordination chemistry has been investigated. The different ligand topology and the arsenic substituents govern the reactivity of the ligands. We report various crystal structures of palladium and platinum complexes derived from this family of ligands. The biphenyl backbone of the bridged bidentate ligands allows very flexible coordination. We have also studied the application of an allylic Pd complex in nucleophilic substitution reactions, revealing that the benzoarsole substituent is susceptible to metal insertion.

National Category
Inorganic Chemistry
Identifiers
urn:nbn:se:uu:diva-322810 (URN)10.1021/acs.inorgchem.7b00100 (DOI)000399625600030 ()28345894 (PubMedID)
Available from: 2017-06-08 Created: 2017-06-08 Last updated: 2017-06-08Bibliographically approved
El Nahhas, A., Shameem, M. A., Chabera, P., Uhlig, J. & Orthaber, A. (2017). Synthesis and Characterization of Cyclopentadithiophene Heterofulvenes: Design Tools for Light-Activated Processes. Chemistry - A European Journal, 23(24), 5673-5677
Open this publication in new window or tab >>Synthesis and Characterization of Cyclopentadithiophene Heterofulvenes: Design Tools for Light-Activated Processes
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2017 (English)In: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 23, no 24, p. 5673-5677Article in journal (Refereed) Published
Abstract [en]

The development of new materials for solar-to-energy conversion should consider stability, ease of fabrication, and beneficial photophysical properties. In this context, a set of novel -conjugated building blocks, with phospha- and arsaalkenes possessing a unique dithienyl annulated heterofulvenoid core, have been prepared as air- and moisture-stable sensitizers. These compounds unify electron-donor and -acceptor moieties, making them potential candidates for light-harvesting applications. Optical characterization of these systems was performed by steady-state and time-resolved absorption spectroscopy, supported by time-dependent DFT calculations. Tuning of the optical properties of these systems can be achieved by varying the pnictogen element at the bridgehead position, giving a bathochromic shift of approximate to 40nm and coordinating the phosphaalkene towards gold Au-I centers. The latter results in a approximate to 2000-fold extension of the approximate to 10ps lifetime of uncoordinated systems well into the ns regime.

Place, publisher, year, edition, pages
WILEY-V C H VERLAG GMBH, 2017
Keywords
arsaalkene, electrochemistry, main group elements, phosphaalkene, pnictogens, time-resolved spectroscopy
National Category
Chemical Sciences
Identifiers
urn:nbn:se:uu:diva-322721 (URN)10.1002/chem.201700917 (DOI)000400044400006 ()28248442 (PubMedID)
Funder
Swedish Research Council, 2013-4763Knut and Alice Wallenberg FoundationÅForsk (Ångpanneföreningen's Foundation for Research and Development)
Available from: 2017-05-29 Created: 2017-05-29 Last updated: 2017-05-29Bibliographically approved
Arkhypchuk, A. I., Orthaber, A. & Borbas, K. E. (2017). Synthesis and Characterization of Ferrocenyl Chlorins, 1,1'-Ferrocene-Linked Chlorin Dimers, and their BODIPY Analogues. Inorganic Chemistry, 56(5), 3044-3054
Open this publication in new window or tab >>Synthesis and Characterization of Ferrocenyl Chlorins, 1,1'-Ferrocene-Linked Chlorin Dimers, and their BODIPY Analogues
2017 (English)In: Inorganic Chemistry, ISSN 0020-1669, E-ISSN 1520-510X, Vol. 56, no 5, p. 3044-3054Article in journal (Refereed) Published
Abstract [en]

We present the synthesis and characterization of meso-ferrocenyl-substituted hydroporphyrins (chlorins) and 1,1' -linked chlorin dimers. The dipyrromethane chlorin precursors were also transformed into Fc-substituted BODIPYs and 1,1'-ferrocenyl-linked BODIPY dimers. The chlorin dimers were studied by 1D and 2D NMR experiments and DFT calculations, which showed that their solution structures were dependent on the central metal. Monomeric and dimeric Ni(II) chlorins had similar H-1 NMR spectra. Monomeric and dimeric free base, Zn(II), and Pd(II) chlorins, on the other hand, showed significantly more different spectra. The eclipsed conformer of the free base chlorin dimer was calculated to be energetically more favored than the open form. The chlorin and BODIPY fluorescence emissions were quenched in the Fcsubstituted compounds; these could be recovered by oxidation of the Fe(II) center. Cyclic voltammetry showed up to five oxidation waves for the free base chlorin dimer, which suggests that the macrocycles were not behaving independently of each other.

National Category
Inorganic Chemistry
Identifiers
urn:nbn:se:uu:diva-320661 (URN)10.1021/acs.inorgchem.6b03158 (DOI)000395847300076 ()28186734 (PubMedID)
Funder
Swedish Research Council, 2013-4655Stiftelsen Olle Engkvist Byggmästare
Available from: 2017-06-30 Created: 2017-06-30 Last updated: 2017-06-30Bibliographically approved
Das, B., Orthaber, A., Ott, S. & Thapper, A. (2017). Water oxidation catalyzed by mononuclear iron and cobalt polypyridine complexes. Paper presented at 18th International Conference on Biological Inorganic Chemistry (ICBIC), JUL 31-AUG 04, 2017, Florianópolis, BRAZIL. Journal of Biological Inorganic Chemistry, 22(Supplement: 1), S259-S259
Open this publication in new window or tab >>Water oxidation catalyzed by mononuclear iron and cobalt polypyridine complexes
2017 (English)In: Journal of Biological Inorganic Chemistry, ISSN 0949-8257, E-ISSN 1432-1327, Vol. 22, no Supplement: 1, p. S259-S259Article in journal, Meeting abstract (Other academic) Published
Keywords
water oxidation, iron, cobalt
National Category
Inorganic Chemistry
Identifiers
urn:nbn:se:uu:diva-350096 (URN)10.1007/s00775-017-1475-y (DOI)000419606600227 ()
Conference
18th International Conference on Biological Inorganic Chemistry (ICBIC), JUL 31-AUG 04, 2017, Florianópolis, BRAZIL
Funder
Swedish Energy AgencyKnut and Alice Wallenberg FoundationSwedish Research Council
Available from: 2018-05-04 Created: 2018-05-04 Last updated: 2018-05-04Bibliographically approved
Xiong, R., Arkhypchuk, A. I., Kovacs, D., Orthaber, A. & Borbas, K. E. (2016). Directly linked hydroporphyrin dimers. Chemical Communications, 52(58), 9056-9058
Open this publication in new window or tab >>Directly linked hydroporphyrin dimers
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2016 (English)In: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, Vol. 52, no 58, p. 9056-9058Article in journal (Refereed) Published
Abstract [en]

Directly linked hydroporphyrin (chlorin) dimers were accessed regioselectively from bromochlorins. Versatile 15-borylated chlorins were prepared in excellent yield via Miyaura borylation. Suzuki coupling yielded meso-beta-linked homo- and heterodimers, and meso-blinked dimers. The photophysical and electrochemical properties of the dimers are reported.

National Category
Other Chemistry Topics
Identifiers
urn:nbn:se:uu:diva-300581 (URN)10.1039/c6cc00516k (DOI)000379431000018 ()26859412 (PubMedID)
Funder
Swedish Research Council, 2013-4655Stiftelsen Olle Engkvist Byggmästare
Available from: 2016-08-09 Created: 2016-08-09 Last updated: 2017-11-28Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0001-5403-9902

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