Srećko I Kirin

Srećko I Kirin
Ruđer Bošković Institute | RBI

About

68
Publications
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Introduction
Srećko I Kirin currently works at Ruđer Bošković Institute. Srećko does research in Catalysis, Inorganic Chemistry and Supramolecular Chemistry. His current project is 'Minimal artificial enzymes: Expanding the application of "backdoor induction" through new substrates and new asymmetric reactions.'
Additional affiliations
March 2008 - present
Ruđer Bošković Institute
Position
  • Research Associate
April 2006 - December 2007
Pennsylvania State University
Position
  • PostDoc Position
April 2001 - March 2006
Universität Heidelberg
Position
  • PostDoc Position

Publications

Publications (68)
Article
Full-text available
Ferrocene derivatives with mono- (8a–c) and bis-1,2,3-triazolyl (9 and 10a–13c) chelating groups were synthesized by regioselective copper(I)-catalysed 1,3-dipolar cycloaddition of terminal alkynes with ferrocene azides. Metal complexes of the ligands were prepared with Cu(II) and Zn(II) salts. Crystal structures of ligands 9 and 11a were determine...
Article
Amides are common molecules which are most often prepared using benzotriazole oxide coupling reagents. Such amides can be derivatised with compounds that contain a triple carbon-carbon bond in order to...
Article
In this review, we analyze the stereochemistry of hexacoordinated metal complexes with flexible tridentate ligands. Unlike rigid ligands, which can adopt only specific coordination modes, flexible ligands open more possibilities to fine-tuning the system for a specific application. Bis-tridentate [M(A-B-A)2] complexes of flexible ligands can form t...
Article
The crystal structure of tris[dimethyl 5-({1-[(pyridin-2-yl-κ N )carbamoyl-κ O ]ethyl}carbamoyl)benzene-1,3-dicarboxylate]zinc(II) dinitrate acetonitrile trisolvate, [Zn(C 19 H 19 N 3 O 6 ) 3 ](NO 3 ) 2 ·3CH 3 CN or [Zn( L ) 3 ](NO 3 ) 2 ·3CH 3 CN, ( 1 ), has been determined by single-crystal X-ray diffraction. The neutral ligand L coordinates to t...
Article
Full-text available
Heme and nonheme-type flavone synthase enzymes, FS I and FS II are responsible for the synthesis of flavones, which play an important role in various biological processes, and have a wide range of biomedicinal properties including antitumor, antimalarial, and antioxidant activities. To get more insight into the mechanism of this curious enzyme reac...
Article
We present a double-stranded ferrocene pseudopeptide 2b which exhibits stimuli responsive chirality inversion triggered by solvent exchange or acid addition. Compound 2b exists as a mixture of self-assembled fast exchanging oligomers which macroscopically behave as a chiroptical switch with two stable states. The ferrocene group inversion results i...
Article
p-Disubstituted phenyldiketopiperazines 1 (R = H), 2 (R = NO2) and 3 (R = -N(CH3)2) were synthesized and characterized by NMR in solution and IR spectroscopy. The identity of the compounds was confirmed and their fragmentation analyzed by ESI-MS and HRMS spectrometry. X-ray single crystal structures revealed that the three compounds crystallize in...
Article
Three novel structures of 9,10-anthracene amino acid conjugates have been determined by combination of single crystal and powder X-ray diffraction measurements, pseudopotential plane wave DFT optimizations and ¹³C solid state NMR spectroscopy, including GIPAW calculation of the NMR parameters. All three structures show anti-conformation of amino ac...
Article
Chelating 1,4-disubstituted mono- (8a−8d) and bis-1,2,3-triazole-based (9a−11a) ligands were prepared by regioselective copper(I)-catalysed 1,3-dipolar cycloaddition of terminal alkynes with aromatic azides, together with bioconjugate 13a synthesized by amide coupling of L-phenylalanine methyl ester to 11a. Cu(II) and Zn(II) complexes were prepared...
Preprint
Chelating 1,4-disubstituted mono- (8a−8d) and bis-1,2,3-triazole-based (9a−11a) ligands were prepared by regioselective copper(I)-catalysed 1,3-dipolar cycloaddition of terminal alkynes with aromatic azides, together with bioconjugate 13a synthesized by amide coupling of L-phenylalanine methyl ester to 11a. Cu(II) and Zn(II) complexes were prepared...
Preprint
Chelating 1,4-disubstituted mono- (8a−8d) and bis-1,2,3-triazole-based (9a−11a) ligands were prepared by regioselective copper(I)-catalysed 1,3-dipolar cycloaddition of terminal alkynes with aromatic azides, together with bioconjugate 13a synthesized by amide coupling of L-phenylalanine methyl ester to 11a. Cu(II) and Zn(II) complexes were prepared...
Article
A variety of structurally different complexes of the isopropyl-bis(2-picolyl)amine (iPr-bpa) ligand were prepared with ZnA2 and CuA2 salts (A = Br─, Br─/PF6─, BF4─/F─, ClO4─). The choice of different counterion affected the stoichiometry, coordination number, geometry and formation of geometrical isomers. Crystal structures of four Zn(II) complexes...
Article
Metal complexes of iminodiacetamide (imda) ligands and metal ions Zn(II), Cu(II), Ni(II), and Co(II) were prepared using eight imda ligands (L1-L8) substituted with groups of different steric and electronic properties on the central amine N atom (H atom, methyl, isopropyl, and benzyl) and the para position of the phenyl rings (nitro and dimethylami...
Article
Full-text available
The Cover Feature shows a supramolecular catalytic system, envisioned as a factory machine. The worker uses a chiral cyclohexane to control the chirality in the remote rhodium machine head which does the selective hydrogenation reaction. The transfer of chirality is achieved by stacked phenyl‐phosphine gears shown in the insides of the machine. The...
Article
(p-Cymene)-ruthenium bioconjugates ML (1) and ML 2 (2), bearing phosphane ligands substituted with chiral or non-chiral amino acid esters, L, were synthetized and characterized by instrumental methods (NMR, CD, MS) and DFT calculations (using the wB97xD functional). Cytotoxic activity of complexes 1 and 2 was investigated by using human cervical ca...
Article
This paper describes the synthesis and characterization of 21 chiral monodentate ligands L, assembled of three building blocks utilizing amide bonds: a metal binding triphenylphosphine, a chiral cyclic diamine and an additional substituent for fine‐tuning the steric and/or electronic properties. Cis square‐planar metal complexes of Rh(I) and Pt(II)...
Article
The trans-configured square-planar complex of dichloropalladium and chiral monodentate phosphine ligands forms self-complementary dimers through 16 hydrogen bonded amides and π-π stacking in chlorinated solvents. The self-assembly is controled by cis-trans isomerisation of the metal center, where trans-configuration governs the dimer formation.
Article
Full-text available
Triphenyphosphine amino acid bioconjugates Ph2P-pC6H4-Aaa-OR, Aa = glycine (1G), alanine (2A), valine (3V), isoleucine (4I), proline (5P) or phenylalanine (6F), have been synthesized and used as monodentate ligands for the preparation of twelve metal complexes, [MCl2(Lig)2], M = Pd(II) or Pt(II). All prepared compounds were characterized by spectro...
Article
Non-covalent self-assembled chiral alanyl aminopyridine ligand exhibits supramolecular chirality in solution, independent of the organic solvent used. The supramolecular chirality of the assemblies is completely inverted by complexation to zinc ions. Up to now, such supramolecular metal-ligand system has not been reported in the literature.
Article
Full-text available
This paper describes the synthesis of an amide based conjugate of ferrocene (Fc), ethylenediamine (eda) and iminodiacetamide (imda), Fc-eda-imda (2). The compound (2) is characterized by various spectroscopic, crystallographic and thermoanalytical techniques in solid state and in solution. By crystallization of the title compound 2 from methanol or...
Article
Full-text available
Metal complexes with ML or ML2 stoichiometry have been isolated in the reaction of Zn(NO3)2, ZnBr2 or M(NO3)2 / Na(BF4)2, M = Zn(II), Co(II) or Ni(II), with either amino acid or amine substituted tridentate nitrogen ligands based on bis(2-picolyl)amine (bpa) or bis(2-quinolidylmethyl)amine (bqa). The stoichiometry (M : L = 1:1 or 1:2) and stereoche...
Article
In this study, we developed an effective approach for increasing the equilibrium adsorption capacity of the interpenetrating polymer networks (IPNs) toward polar aromatic compounds. For this purpose, a novel post-cross-linked polystyrene/poly (methyl acryloyl diethylenetriamine) (CMPS_pc/PMADETA) IPNs was synthesized and its adsorption was evaluate...
Article
Full-text available
Proteins were proved to be type-independent templates for the biomineralization of iron ions into hematite mesocrystals with tunable structures and morphologies under hydrothemal conditions. Our finding could pave the way for the synthesis of mesocrystals with controlled stuctures and morphologies using templates of low-cost proteins.
Article
Bioconjugate bidentate ligands 2-10 were obtained by tethering triphenylphosphanecarboxylic acid to amino acid substituted spacers with different flexibility, ranging from a rigid enediyne-based beta-turn inducer to flexible linear aliphatic chains with up to eight carbon atoms. The 21 synthesized ligands revealed up to 81% ee selectivity in rhodiu...
Article
Full-text available
This paper describes the synthesis and characterization of 5-(diphenylphosphanyl)isophthalic acid bioconjugates (Lig-[R]2). In addition to symmetrically disubstituted conjugates with amino acids, peptides or amines, a convenient one-pot, two-step procedure for the synthesis of conjugates bearing two different substituents is reported. The 28 prepar...
Article
Full-text available
Pseudo-peptide Me2N-pC6H4C(O)-Phe-OEt (1) exhibits two polymorphic forms which crystallizes in non-centrosymmetric space groups, monoclinic 1m (P21) and orthorhombic 1o (P212121). Both forms occur concomitantly or as a pure phase depending on the solvent of crystallization. Single crystal X-ray diffraction revealed equivalent two-dimensional layers...
Article
Full-text available
Amino acid substituted monodentate triphenylphosphine ligands Lig-Aa(1)-Aa(2)-Aa(3)-Z 5 and 6, with a C-terminal ester or amide group, respectively, were prepared in a few simple synthetic steps. Supramolecular in situ formed complexes [Rh(COD)( Lig-Aa(1)-Aa(2)-Aa(3)-Z)(2)]BF4 3 and 4 with a prochiral coordination sphere of the metal are selective...
Article
The synthesis and spectroscopic characterization of 21 l,l′-disubstituted ferrocenoyl peptides of the general formula [Fe(C5H4-CO-Aal-OR) (C5H4-CO-Aa2-OR′)] is reported, with Aal and Aa2 being different amino acids. The one-pot synthesis from activated ferrocene-l,l′-dicarboxylic acid and two different amino acid esters gives the unsymmetrical ferr...
Article
Using mono- and 1,n′-disubstituted ferrocenecarboxylic acid, the aminoethylglycine (aeg) derivatives Fe[C5H4-CO-aeg-OtBu][C5H5] (1) and Fe[C5H4-CO-aeg-OtBu]2 (2) have been synthesized. Complexes 1 and 2 are further reacted to substitute the aeg with the nitrogen-containing ligands dpa-ph-CO2H or py-AcOH to yield complexes 3–6. Each of these is trea...
Article
The metal does the trick! Atomic absorption spectroscopy (AAS) of cobalt atoms is used as an accurate method to determine the cellular uptake and nuclear localization of metal bioconjugates. Surprisingly, the PNA conjugates show highest uptake efficiency, and an accumulation 150 % higher than in the culture medium is achieved.
Article
Das Metall bringt's! Die Atomabsorptionsspektroskopie (AAS) von Cobaltatomen erwies sich als geeignete Methode zur Untersuchung der Zellaufnahme und Lokalisierung im Zellkern von Metall-Biokonjugaten. Überraschenderweise zeigen Peptidnucleinsäure(PNA)-Konjugate die höchste Zellaufnahme mit einer Anreicherung von bis zu 150 % gegenüber dem Zellkultu...
Article
This work reports structural investigations on two metal complexes of the functionalized (p-carboxylatobenzyl)-bis(2-picolyl)amine ligand 1 (HL). The complex {[HLPdCl]Cl × H2O}2 (2Pd) has a square-planar coordination around the Pd ion. It forms discrete dimers by intermolecular hydrogen bonding involving the protonated ligand HL. The coordination a...
Article
Aminoferrocene, H2N–Fc, has been substituted to the C-terminus of six amino acids using the HBTU/HOBt coupling protocol. The synthesized bioconjugates Boc-Aaa-NH-Fc, Aaa=Gly (1), Leu (2), Phe (3), Val (4), Cys(Acm) (5), Tyr(tBu) (6) (Acm=acetamidomethyl, tBu=tert-butyl), have been characterized by 1H NMR, 13C NMR, EI-MS, EI-HRMS, UV and CD spectros...
Article
The two-step syntheses of the substituted di(2-pyridyl)amine ligands (dpa), dpa-CH2CO2H (1) and dpa-PhCO2H (2), are described. Ligands 1 and 2 are successfully coupled to the amino acid phenylalanine, yielding the derivatives 4 and 6, respectively. Four CuII(dpa)2 complexes, [Cu(dpa-CH2CO2tBu)2(NO3)2] (3Cu), [Cu(dpa-CH2CO-PheOMe)2(H2O)2](NO3)2·2MeO...
Article
The inorganic nucleoside analog [Boc-aeg{Cu(pda)py-Ac}-OMe] (3) is prepared and fully characterized. The X-ray single crystal analysis reveals that 3 assembles by apical Cu-O bonds into a coordination polymer, with short Cu-Cu distances of 5.32 and 5.78 angstrom. The solid state structure of 3 is in accordance with an isotactic structural model for...
Article
Full-text available
The investigation of RNA structure, dynamics and biological function often requires the site-specific incorporation of non-natural moieties. Here we describe the functionalization of RNA transcripts by aldehyde–hydrazine chemistry using a simple initiator nucleotide that carries an acetal-protected aldehyde function. This initiator nucleotide was e...
Article
We describe a simple procedure for the manual solid-phase synthesis of peptides. No expensive or specialized equipment is needed. Moreover, a variety of markers can be attached to the N-terminus. We describe two organometallic markers and a fluroescent dye, in addition to an unlabeled derivative that serves as a comparison. The experiment described...
Article
Eight novel thioesters were obtained and characterized by elemental analysis, mass spectrometry, infrared and NMR spectroscopy. The data were analyzed on the basis of the relevant resonance structures. The X-ray single crystal structure of o-methoxythiophenyl 4-methylbenzoate is reported.
Article
An experimental and computational study on the conformational preference of 1,n′-disubstituted ferrocenoyl amino acids and dipeptides is presented. Only l-amino acids were used for the synthesis of Fe[C5H4-CO-Met-Met-OMe]2 (4), but according to the X-ray structure a 4:1 mixture of l,d,M,d,l and l,d,M,l,l isomers is obtained (l describes amino acid...
Article
The solid phase synthesis of PNA oligomers with the internal dipeptide Gly-Phe is presented and the interaction with complementary DNA investigated. UV absorbance melting experiments with different but complementary DNA sequences show that stable PNA x DNA duplexes are only obtained when there is no DNA base opposite the dipeptide unit. Instead, th...
Article
We present a detailed structural study of peptide derivatives of 1'-aminoferrocene-1-carboxylic acid (ferrocene amino acid, Fca), one of the simplest organometallic amino acids. Fca was incorporated into di- to pentapeptides with D- and L-alanine residues attached to either the carboxy or amino group, or to both. Crystallographic and spectroscopic...
Article
Full-text available
Ferrocene peptide conjugates display an array of structural features including helical ferrocene based chirality and a number of different intramolecular hydrogen bonding patterns. In this tutorial review we present a rigorous nomenclature for these systems, followed by a section that summarises and categorises the structures known to date. The iss...
Article
Abstract 10.1002/ejoc.200500377.abs The high-pressure synthesis of new rod-like and U-shaped polycyclic compounds containing two 7-metallonorbornene (silicon or germanium) units fused to the 7-oxanorbornene rings is described. In addition, the structural features of adduct 9 established by X-ray structure determination and DFT calculations of model...
Article
Full-text available
We present a systematic study on unsymmetrical amino acid derivatives of 1,1'- ferrocene dicarboxylic acid. A convenient and general one pot synthetic procedure is presented in which the unsymmetrical amino acid derivatives are readily separated by column chromatography. The following ferrocene derivatives Fe[C(5)H(4)- CO- Aaa(1)- OMe][ C(5)H(4)- C...
Article
Four chelating nitrogen ligands 2-5 derived from N,N-bis(2-picolyl)amine (bpa, 1) were synthesized, namely, (PyCH(2))(2)N-CH(2)-p-C(6)H(4)-CO(2)R (R = Me, 2, and R = H, 3) and (PyCH(2))(2)N-(CH(2))(n)-CO(2)H (n = 2, 4, and n = 5, 5). Amino acid conjugates 6 and 7 were formed by condensation of 3 with H-Phe-OMe and H-betaAla-OMe, respectively. Cu(II...
Article
Full-text available
The unnatural organometallic amino acid 1'-aminoferrocene-1-carboxylic acid (Fca) induces a turn structure in a tetrapeptide with anti-parallel strands which is stabilized by two intra-molecular hydrogen bonds in the solid state and in solution.
Article
Full-text available
Complexes of a N,N-bis(2-picolyl)amine (bpa) derivative with a pendant ethoxyethanol side chain (bpa(CH2)2O(CH2)2OH) (1) with late divalent transition metal ions Co(II), Ni(II), Cu(II) and Zn(II) have been studied. All complexes, [[bpa(CH2)2O(CH2)2OH]Co(NO3)](NO3) (1Co), [[bpa(CH2)2O(CH2)2OH]Ni(NO3)](NO3) (1Ni), [[bpa(CH2)2O(CH2)2OH]Cu(H2O)(NO3)](N...
Article
The main electron ionisation induced fragmentation processes of fused norbornene analogues containing SiMe2 or GeMe2 and oxygen bridges, as well as their dependence on substitution, were investigated using mass (MS) and tandem mass (MS/MS) spectrometric analysis. Formation of the rearrangement ions of m/z 176 in the mass spectra of fused norbornene...
Article
The synthesis of fused norbornene analogues containing silicon and oxygen atoms in bridgehead positions is reported. This novel type of compound can be readily obtained in stereospecific Diels-Alder [4+2] cycloaddition of siloles with oxanorbornene derivatives as appropriate dienophiles by the use of high pressure (9 kbar).
Article
Preparation of a novel type of cycloadducts composed of a 7-silanorbornene ring condensed to the 7-oxanorbornene moiety (5–7) is described and their spectroscopic features are discussed in detail. The X-ray data for 5 are also presented. Finally, formation of silanole 8 by nucleophilic cleavage of an endocyclic silicon–carbon bond in 7 is described...
Article
Cu(I) complexes of monodentate ligands R-2,4-diphenyloxazoline (1) and R-2-isopropyl-4-phenyloxazoline (2) exhibit significant increase of enantioselectivity in cyclopropanation of styrene versus ligands 3–6, indicating participation in the catalytic cycles of conformationally distinguishable 2:1 (ligand/Cu) complexes, stabilized by π stacking of p...
Article
CD study of the chiral enamines 4-9 revealed the presence of the azastil-bene-like chromophore, and exciton coupling between this chromophore (A) and aromatic chromophore B. Coupled excitons in 5 and 8 suggest M (−) absolute conformation between chromophores A and B. © 1996 Wiley-Liss, Inc.
Article
Optically active enamines of 2-(2′-pyrido)acetophenone or 2-(2′-quinolino)acetophenone with (R)-1-phenylethylamine, (R)-1-(1-naphthyl)ethylamine, (R)-cyclohexylethylamine, and (R)-phenylglycinol were prepared and their copper(I) complexes used in the enantioselective cyclopropanation of styrene with ethyl- and menthyldiazoacetate. Enantioselectivit...
Article
Full-text available
The X-ray crystal structure of (R,S)--amino--caprolactone hydrochloride (compound1) and -amino--methyl--valerolactone hydrochloride semihydrate (compound2) are presented. Both compound1 and compound2 belong to the orthorhombic system. Caprolactone-hydrochloride1 crystallizes in the space groupP212121 witha=5.1948(7),b=8.7404(8),c=17.907(1) .V=813.0...
Article
Full-text available
The molecule of the tide compound, bis(2-amino-4-hydroxypentanoato-N,O,O'')copper(II), possesses crystallographic 1BAR symmetry. The Cu coordination geometry is distorted square bipyramidal. By virtue of the centre of symmetry, the metal atom and four of the six ligand donor atoms are in an equatorial plane and are rigorously coplanar. The structur...

Projects

Projects (2)
Project
This project aims at the development of chiral transition metal catalysts with particular emphasis on inspiration taken from nature. A beta-turn structure is proposed as key feature of chiral catalysts that resemble artificial enzymes with a minimal but functional outer-coordination sphere. These minimal artificial enzymes could find applications in asymmetric synthesis of drugs or drug intermediates produced by pharmaceutical industry. In asymmetric catalysis it is well established that the chiral information should be incorporated as close as possible to the coordination sphere of the catalytic metal. We challenge this important principle and use a catalytic metal center that is only prochiral. The chirality is transmitted by "backdoor induction" via hydrogen bonding of distant pendant amino acids that represent the outer-coordination sphere. Preliminary results provide a proof of concept and strongly indicate that simple amino acid bioconjugates of monodentate triphenylphosphane ligands can form supramolecular L2M complexes with Rh(I) that selectively catalyze a model asymmetric hydrogenation reaction with major impact of the distant amino acid sequence on selectivity [Kirin and Kokan, RSC Adv. 2012, Eur. J. Org. Chem. 2013 and Organometallics 2014; ee’s up to 84 %]. Within this project, a significant extension is proposed including (i) the use of new ligand bioconjugates with phosphorous or nitrogen donor atoms, (ii) the use of new substrates and (iii) the use of other transition metals for different asymmetric reactions, namely Ru(II)-catalyzed hydrogenation, Pd(II)-catalyzed alkylation and Ln(III) catalyzed silylcyanation.
Archived project
Organometallic nucleobase derivatives (OrDeNs) correspond to a new generation of conjugates in which metallocenes are linked to the basic structural elements of heredity. Due to their electrophoric and bioactive properties, OrDeNs are of use in (bio)analytical and medicinal chemistry. The preparation of OrDeNs is based on the copulation reaction between the organometallic part with a heterocyclic base, by using different linkers. The choice of fragments usually follows the target of the ever-growing diversity of structural motifs. In this project all modifications of OrDeNs structures will be directed toward derivatives with marked electrochemical and biological properties.