TY  - JOUR
A1  - Benassi, Rois
A1  - Bregulla, Antje
A1  - Friedrich, Alwin
A1  - Henning, Dietrich
A1  - Heydenreich, Matthias
A1  - Mickler, Wulfhard
A1  - Kleinpeter, Erich
A1  - Kempter, Gerhard
A1  - Schilde, Uwe
A1  - Taddei, F.
T1  - NMR spectroscopic and theoretical structural study of 5-exo-methylene-substituted hydantoins
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Kleinpeter, Erich
A1  - Heydenreich, Matthias
A1  - Woller, Jochen
A1  - Wolf, Gunter
A1  - Koch, Andreas
A1  - Kempter, Gerhard
A1  - Pihlaja, Kalevi
T1  - Configuration and stereodynamics of exo/endoisomeric push-pull alkenes of pentadiene structure
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Kleinpeter, Erich
A1  - Heydenreich, Matthias
A1  - Kalder, L.
A1  - Koch, Andreas
A1  - Henning, Dietrich
A1  - Kempter, Gerhard
T1  - NMR spectroscopic and theoretical structural analysis of 5,5-disubstituted hydantoins in solution
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Heydenreich, Matthias
A1  - Koch, Andreas
A1  - Ristau, Thomas
A1  - Knoll, Susanne
A1  - Heinicke, Jochen
A1  - Sieler, Joachim
A1  - Niemitz, Matthias
A1  - Mühlstädt, Manfred
A1  - Kleinpeter, Erich
T1  - Conformational analysis of sulfur-containing heterocycles ; part I: synthesis and structural determination of diastereomerically pure 4,6-bis(phenoxymethyl)-1,2,5-trithiepanes
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Heydenreich, Matthias
A1  - Koch, Andreas
A1  - Kleinpeter, Erich
A1  - Zimmermann, Thomas
T1  - Dynamic NMR study of the flexibility of 2-amino-3-aroyl-4,6-diaryl-pyrylium salts
Y1  - 1997
UR  - http://www.springerlink.com/content/110258
U6  - https://doi.org/10.1007/s002160050205
SN  - 0937-0633
ER  - 
TY  - JOUR
A1  - Kleinpeter, Erich
A1  - Heydenreich, Matthias
A1  - Kalder, L.
A1  - Koch, Andreas
A1  - Henning, Dietrich
A1  - Kempter, Gerhard
A1  - Benassi, Rois
A1  - Taddei, F.
T1  - NMR spectroscopic and theoretical structural analysis of 5,5-disubstituted hydantoins in solution
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Kleinpeter, Erich
A1  - Koch, Andreas
A1  - Heydenreich, Matthias
A1  - Chatterjee, S. K.
A1  - Rudorf, Wolf-Dieter
T1  - Study of the pi-electron distribution in push-pull alkenes by 1H and 13C NMR spectroscopy, IV : the conformation and dynamic behaviour of substituted N-Phenyl-2,3-dihydro-4(1H)-pyridones
Y1  - 1995
ER  - 
TY  - JOUR
A1  - Kleinpeter, Erich
A1  - Szatmári, István
A1  - Lázár, László
A1  - Koch, Andreas
A1  - Heydenreich, Matthias
A1  - Fulop, Ferenc
T1  - Visualization and quantification of anisotropic effects on the 1H NMR spectra of 1,3-oxazino[4,3- alpha]isoquinolines - indirect estimates of steric compression
N2  - The anisotropic effects of the phenyl, alpha- and beta-naphthyl moieties in four series of 1,3-oxazino[4,3- a]isoquinolines on the H-1 chemical shifts of the isoquinoline protons were calculated by employing the Nucleus Independent Chemical Shift (NICS) concept and Visualized as anisotropic cones by a through-space NMR shielding grid. The signs and extents of these spatial effects on the H-1 chemical shifts of the isoquinoline protons were compared with the experimental H-1 NMR spectra. The differences between the experimental delta (H-1)/ppm values and the calculated anisotropic effects of the aromatic moieties are discussed in terms of the steric compression that occurs in the Compounds studied.
Y1  - 2009
U6  - https://doi.org/10.1016/j.tet.2009.07.038
SN  - 0040-4020
ER  - 
TY  - JOUR
A1  - Kleinpeter, Erich
A1  - Heydenreich, Matthias
A1  - Chatterjee, S. K.
A1  - Rudorf, Wolf-Dieter
T1  - Study of the pi-electron distribution in push-pull alkenes by 1H and 13C NMR spectroscopy, III : the conformation of 3,4-Dihydro-4-oxo-2H-thiins
Y1  - 1994
ER  - 
TY  - JOUR
A1  - Kleinpeter, Erich
A1  - Heydenreich, Matthias
A1  - Chatterjee, S. K.
A1  - Rudorf, Wolf-Dieter
T1  - Study of the pi-electron distribution in push-pull alkenes by 1H and 13C NMR spectroscopy
Y1  - 1994
ER  - 
TY  - JOUR
A1  - Sarodnick, Gerhard
A1  - Linker, Torsten
A1  - Heydenreich, Matthias
A1  - Koch, Andreas
A1  - Starke, Ines
A1  - Fürstenberg, Sylvia
A1  - Kleinpeter, Erich
T1  - Quinoxalines XV : convenient synthesis and structural study of pyrazolo[1,5-alpha]quinoxalines
N2  - A series of aryloxymethylquinoxaline oximes, hitherto unknown and synthesized from the corresponding aldehydes, afforded in only one step pyrazolo[1,5-;]quinoxalines in the presence of acetic anhydride at high temperatures. A formal [3,5]-sigmatropic rearrangement was proposed as the mechanistic rationale for this unprecedented transformation. Saponification with potassium hydroxide furnished the free phenol derivatives which were studied by NMR spectroscopy and accompanying theoretical DFT calculations, establishing intramolecular hydrogen bonding and the spatial magnetic properties. Additionally, mass spectrometric fragmentation was investigated by B/E-linked scans and collision-induced dissociation experiments. The fragmentation pattern devoted a new gas phase rearrangement process, which proved to be unique and characteristic for pyrazolo[1,5-;]quinoxalines.
Y1  - 2009
UR  - http://pubs.acs.org/journal/joceah
U6  - https://doi.org/10.1021/Jo802398g
SN  - 0022-3263
ER  - 
TY  - JOUR
A1  - Szatmari, Istvan
A1  - Toth, Diana
A1  - Koch, Andreas
A1  - Heydenreich, Matthias
A1  - Kleinpeter, Erich
A1  - Fulop, Ferenc
T1  - Study of the substituent-influenced anomeric effect in the ring-chain tautomerism of 1-alkyl-3-aryl-naphth[1,2- e][1,3]oxazines
N2  - The stabilities of the trans (B) and cis (C) tautomeric ring forms that are experimentally observed in the ring- chain tautomeric interconversion of 1-alkyl-3-aryl-2,3-dihydro-1H-naphth[1,2-e][1,3]oxazines has been investigated. Stability differences are explained by the analysis of the natural bond orbital results for the lone pairs of electrons that are on the heteroatoms in the oxazine ring system and by regression analysis of the calculated 13C NMR chemical shift values.
Y1  - 2006
UR  - http://onlinelibrary.wiley.com/doi/10.1002/ejoc.200600563/pdf
U6  - https://doi.org/10.1002/ejoc.200600563
ER  - 
TY  - JOUR
A1  - Kihampa, Charles
A1  - Nkunya, Mayunga H. H.
A1  - Joseph, Cosam C.
A1  - Magesa, Stephen M.
A1  - Hassanali, Ahmed
A1  - Heydenreich, Matthias
A1  - Kleinpeter, Erich
T1  - Anti-mosquito and antimicrobial nor-halimanoids, isocoumarins and an anilinoid from Tessmannia densiflora
N2  - The nor-halimane diterpenoid tessmannic acid and its methyl, 2-methylisopropyl and 1-methylbutyl esters, the unusual isocoumarins 8-hydroxy-6-methoxy-3-pentylisocoumarin and 7-chloro-8-hydroxy-6-methoxy-3-pentylisocoumarin, and 5- pentyl-3-methoxy-N-butylaniline were isolated from the stem and root bark extracts of Tessmannia densiflora Harms (Caesalpiniaceae) that showed mosquito larvicidal activity. The structures were determined on interpretation of spectroscopic data. Tessmannic acid and its methyl ester exhibited antibacterial and antifungal activity. The compounds also caused high larvae and adult Anopheles gambiae mosquitoe mortality effects, and stronger mosquito repellency than that shown by the standard repellent DEET, hence indicating Tessmannia species to be potential sources of bioactive natural products.
Y1  - 2009
UR  - http://www.sciencedirect.com/science/journal/00319422
U6  - https://doi.org/10.1016/j.phytochem.2009.07.024
SN  - 0031-9422
ER  - 
TY  - JOUR
A1  - Thóth, Diána
A1  - Szatmári, István
A1  - Heydenreich, Matthias
A1  - Koch, Andreas
A1  - Kleinpeter, Erich
A1  - Fulop, Ferenc
T1  - Synthesis and conformational analysis of naphthylnaphthoxazine derivatives
N2  - Four new primary aminonaphthols (4, 5, 9 and 10) were synthesized from 1- or 2-naphthol and 1- or 2- naphthaldehyde via naphthoxazines in modified Mannich condensations. Simple ring-closure reactions of these aminonaphthols with paraformaldehyde, 4-nitrobenzaldehyde, phosgene or 4-chlorophenyl isothiocyanate led to new heterocyclic derivatives. In these transformations, either an sp2 or an sp3 carbon was inserted between the hydroxy and amino groups. The effects of substituents and the naphthyl ring on the conformation were investigated by means of NMR measurements, employing both dipolar and scalar couplings. The structures were confirmed by DFT quantum chemical calculations involving computed coupling constants, intramolecular distances between nuclei and the relative energies of the preferred conformers.
Y1  - 2009
UR  - http://www.sciencedirect.com/science/journal/00222860
U6  - https://doi.org/10.1016/j.molstruc.2009.04.015
SN  - 0166-1280
ER  - 
TY  - JOUR
A1  - Schuster, Ildikó
A1  - Koch, Andreas
A1  - Heydenreich, Matthias
A1  - Kleinpeter, Erich
A1  - Forró, Enikö
A1  - Lázár, László
A1  - Sillanpää, Reijo
A1  - Fulop, Ferenc
T1  - Synthesis and Conformational Analysis of Tetrahydroisoquinoline-Fused 1,3,2-Oxazaphospholidines and 1,2,3- Oxathiazolidines
N2  - The cyclizations of tetrahydroisoquinoline 1,2-amino alcohols with phenylphosphonic dichloride, bis(2- chloroethyl)phosphoramidic dichloride, thionyl chloride and sulfuryl chloride were utilized to synthesize 1,5,6,10b- tetrahydro-1,3,2-oxazaphospholo[4,3-a]isoquinolines (2, 3), 1,5,10,10a-tetrahydro-1,3,2-oxazaphospholo[3,4- b]isoquinolines (8, 9), 1,5,6,10b-tetrahydro-1,2,3-oxathiazolo[4,3-a]isoquinolines (4-6) anda 1,5,10,10a-tetrahydro- 1,2,3-oxathiazolo[3,4-b]isoquinoline (11), which are the first representatives of these ring systems. NMR spectroscopic analysis revealed the existence of conformational equilibria that are fast on the NMR timescale. Theoretical DFT calculations pointed to the participation of generally two preferred conformers in the conformational equilibria; the positions of the equilibria were indicated by the experimental NMR spectroscopic parameters, and they are in good agreement with the theoretically calculated energy differences of the participating conformers. For two compounds, which could be not isolated (10, 12), both the preferred conformers and the stereochemistry could be concluded from the DFT calculation results.
Y1  - 2008
ER  - 
TY  - JOUR
A1  - Holdt, Hans-Jürgen
A1  - Müller, Holger
A1  - Potter, Matthias
A1  - Kelling, Alexandra
A1  - Schilde, Uwe
A1  - Starke, Ines
A1  - Heydenreich, Matthias
A1  - Kleinpeter, Erich
T1  - The first sandwich complex with an octa(thioether) coordination sphere : Bis(maleonitrile-tetrathia-12-crown- 4)silver(I)
N2  - The new tetrathiacrown ethers maleonitrile-tetrathia-12-crown-4 (mn12S(4)) and maleonitrile-tetrathia-13-crown- 4 (mn13S(4)) have been prepared and characterised by X-ray crystallographic analysis. These crown ethers form 2:1, 3:2 and 1: 1 complexes with AgY (Y = BF4, PF6). The crystal structures of [Ag(mn12S(4))(2)]BF4 (3a), [Ag(mn13S(4))(2)]BF4 (4a) and [Ag-2(mn13S(4))(3)](PF6)(2) (6b) have been determined. Compound 3a contains the centrosymmetric sandwich complex cation [Ag(mn12S(4))(2)](+) where each mn12S(4) ligand is coordinated to the Ag centre in an endo manner through all four S atoms. The 2:1 complex [Ag(mn12S(4))(2)](+) is the first sandwich complex with a tetrathiacrown ether and the first complex with an octa(thioether) coordination sphere. The crystal structure of compound 4a also reveals a 2:1 complex. This complex, [Ag(mnl3S(4))(2)](+), exhibits a half-sandwich structure. One mn13S(4) ligand coordinates to Ag+ by all four S donor atoms and the other 13S(4) crown by only one S atom. Compound 6b contains a dinuclear Ag complex. The Ag complexes 3a,b-8a,b were also studied by electrospray ionisation mass spectrometry. Collision-induced dissociation (CID) was used to compare the relative stability of 2:1 complexes [AgL2]+ and 1:1 complexes [AgL](+) (L = mn12S(4), mn13S(4)). The C-13 NMR chemical shifts of 2:1 and 1:1 Ag complexes and their corresponding free ligands were also estimated and compared. The free energy of the barrier of ring inversion (Delta G(double dagger)) for [Ag(mn12S(4))(2)](+) was determined to be 64 kJmol(-1).
Y1  - 2006
UR  - http://www3.interscience.wiley.com/cgi-bin/jhome/27721/
U6  - https://doi.org/10.1002/ejic.200501109
SN  - 1434-1948
ER  - 
TY  - JOUR
A1  - Heydenreich, Matthias
A1  - Koch, Andreas
A1  - Klod, Sabrina
A1  - Szatmari, Istvan
A1  - Fulop, Ferenc
A1  - Kleinpeter, Erich
T1  - Synthesis and conformational analysis of naphth[1', 2':5,6][1,3]oxazino[3,2-c][1,3]benzoxazine and naphth[1', 2':5,6][1,3]oxazino[3,4-c][1,3]benzoxazine derivatives
JF  - Tetrahedron
N2  - A new functional group, the hydroxy group, was inserted into a Betti base by reaction with salicylaldehyde, and the naphthoxazine derivatives thus obtained were converted by ring-closure reactions with formaldehyde, acetaldehyde, propionaldehyde or phosgene to the corresponding naphth[1',2':5,6][1,3]oxazino[3,2-c][1,3]benzoxazine derivatives. Further, the conformational analysis of these polycyclic compounds by NMR spectroscopy and an accompanying molecular modelling are reported; especially, both quantitative anisotropic ring current effects of the aromatic moieties in these compounds and steric substituent effects were employed to determine the stereochemistry of the naphthoxazinobenzoxazine derivatives.
Y1  - 2006
UR  - http://www.sciencedirect.com/science/journal/00404020
U6  - https://doi.org/10.1016/j.tet.2006.09.037
SN  - 0040-4020
VL  - 62
IS  - 48
SP  - 11081
EP  - 11089
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Heydenreich, Matthias
A1  - Koch, Andreas
A1  - Sarodnick, Gerhard
A1  - Kleinpeter, Erich
T1  - Quinoxalines XIV : Synthesis, H-1, C-13, N-15 NMR spectroscopic, and quantum chemical study of 1H-pyrazolo[3,4- b]quinoxalines (flavazoles)
N2  - The synthesis of a series of 1H-pyrazolo[3,4-b]quinoxalines (flavazoles) by acylation, alkylation, halogenation, and aminomethylation of the parent compound is reported and their structure is investigated by H-1, C-13 and N-15 NMR spectroscopy. The restricted rotation about the partial C, N double bond of the N-acyl derivatives 7-10 is studied by dynamic NMR spectroscopy and the barriers to rotation are determined. In order to assign unequivocally the 15 N chemical shifts of N-4 and N-9, in case of 3-substituted flavazoles, exemplary the H-1, C-13, and N-15 NMR chemical shifts of 34, 35, and 39 are also theoretically calculated by quantum chemical methods [ab initio at different levels of theory (HF/6-3G* and B3LYP/6-31G*)]. (C) 2005 Elsevier Ltd. All rights reserved
Y1  - 2005
SN  - 0040-4020
ER  - 
TY  - JOUR
A1  - Kleinpeter, Erich
A1  - Marsat, Jean-Noël
A1  - Heydenreich, Matthias
A1  - von Berlepsch, Hans
A1  - Laschewsky, André
T1  - Self-Assembly into Multicompartment Micelles and Selective Solubilization by Hydrophilic-Lipophilic- Fluorophilic Block Copolymers
Y1  - 2011
SN  - 0024-9297
ER  - 
TY  - JOUR
A1  - Kleinpeter, Erich
A1  - Csütörtöki, Renáta
A1  - Szatmári, István
A1  - Heydenreich, Matthias
A1  - Koch, Andreas
A1  - Starke, Ines
A1  - Fulop, Ferenc
T1  - Novel piperidine-fused benzoxazino- and quinazolinonaphthoxazines-synthesis and conformational study
N2  - The reactions of 1-(amino(2-hydroxyphenyl)methyl)-2-naphthol (3) and 1-(amino(2-aminophenyl)methyl)-2-naphthol (6) with glutardialdehyde resulted in the formation of piperidine-fused benzoxazinonaphthoxazine 4 and quinazolinonaphthoxazine 7, respectively, both in diastereopure form. The full conformational search protocols of 4 and 7 were successfully carried out by NMR spectroscopy and accompanying molecular modelling; the global minimum-energy conformers of all diastereomers were computed, and the assignments of the most stable stereoisomers, Gtct1 for 4 and Gtct1 for 7, were corroborated by spatial NOE information relating to the H7a-H10a-H15b and H,H coupling patterns of the protons in the flexible part of the piperidine moiety. Additionally, mass spectrometric fragmentation was investigated in collision-induced dissociation experiments. The elemental compositions of the ions were determined by accurate mass measurements.
Y1  - 2012
SN  - 0040-4020
ER  -