Organisch-Chemisches Institut	Tel. (0251) 83-33210 Fax: (0251) 83-39772 e-mail: orgchem@uni-muenster.de www: uni-muenster.de/Chemie.oc/
Corrensstrasse 40 48149 Münster Geschäftsführender Direktor: Prof. Dr. Stefan Grimme
Forschungsschwerpunkte 2003 - 2004    zurück    weiter

The laboratory of single crystal X-ray structure determination   The laboratory of single crystal X-ray structure determination is working as a service department for the institute and the department. There are several close co-operations with other institutes in Germany, in Europe, and all over the world. The laboratory runs two Enraf-Nonius CAD4-diffractometers and two Nonius KappaCCD diffractometers. One of the conventional diffractometers and one CCD-system are placed on a rotating anode generator, the other CCD-diffractometer is equipped with a detector optimized for Cu-radiation. To meet the requirements of organic and organometallic chemists, both Cu- and Mo-radiation is used. All instruments are equipped with liquid nitrogen cooling devices. A zone-melting device with infrared laser for crystallizing liquids directly on the diffractometer is also available. Preparation of air- or moisture-sensitive crystals is possible under an argon atmosphere or in a glove box. To the laboratory belong several computers of the latest technology, both for controlling the instruments and for solving, refining and presentation of the single crystal X-ray structures. Due to direct access to the Cambridge structural database also structural comparison with known structures is possible. Beside the two permanent positions of a technician and a structural chemist also students and post-docs are working here. The laboratory provides the institute with more than four hundred X-ray structures per year, ready for publication. It is also involved in the teaching of graduate or doctoral students. Publications: B. Kramer, R. Fröhlich, K. Bergander, S. R. Waldvogel: The O-substitution Pattern of the MoCl5-Mediated Oxidative Aryl-Aryl Coupling Reaction. Synthesis, 91 - 96 (2003). S. Venne-Dunker, G. Kehr, R. Fröhlich, G.Erker: Selective Intramolecular [N]CH Activation in Bis(1-ethenylamino-Cp)zirconium-Butadiene Complexes and Related Systems. Organometallics, 22, 948 - 958 (2003). C. Möllers, J. Prigge, B. Wibbeling, R. Fröhlich, A. Brockmeyer, H. J. Schäfer, E. Schmälzlin, C. Bräuchle, K. Meerholz, E.-U. Würthwein: Polyamino-Substituted 1-Oxa-3,5-diazahexatrienes and 1-Oxa-3,5,7-triazooctatetraenes (N-Acyl-oligocyan-amides): Synthesis, Structures, Cyclovoltametry and NLO Porperties - Experiment and Theory. Eur. J. Org. Chem., 1198 - 1208 (2003). S. Döring, V. V. Kotov, G. Erker, G. Kehr, K. Bergander, O. Kataeva, R. Fröhlich: Synthesis and Dynamic Features of (Chloro)zirconocene Cations Stabilised by Pendant (Diarylphosphanyl)alkyl and (Dimethylamino)alkyl Substituents at Their Cyclopentadienyl Ring Systems. Eur. J. Inorg. Chem., 1599 - 1607 (2003). N. B. Singh, A. Pathak, R. Fröhlich: Solid-State Complexation Reaction between p-Benzoquinone and p-Nitroaniline. Aust. J. Chem., 56, 329 - 333 (2003). M. Albrecht, S. Kamptmann, R. Fröhlich: 3,3'-{(1E,2E)-Hydrazine-1,2-diylidene-di[(E)methylylidene]}dibezene-1,2-diol (BCAz-H4): an easy to prepare but very useful building block for the self-assembly of triple-stranded helicates; the X-ray crystal structure of Na4[BCAz)3Ti2].7 dmf .H2O. Polyhedron, 22, 643 - 647 (2003). H. V. Huynh, R. Fröhlich, F. E. Hahn: Synthesis and Molecular Strcuture of [Fe2Cl2(µ-S-tBu)2(η1-η1-µ-dppe)] (dppe= Ph2P(CH2)2PPh2). Z. Naturforsch., 58b, 359 - 361 (2003). G. Haufe, S. Pietz, D. Wölker, R. Fröhlich: Synthesis of Fluorinated Cycloalkyl N-Phenylcarbamates and Their Microbial Defluorination/Oxygenation by Beauveria bassiana. Eur. J. Org. Chem., 2166 - 2175 (2003). D. Vagedes, G. Erker, G. Kehr, R. Fröhlich, S. Grimme, C. Mück-Lichtenfeld: Formation of a Doubly C,N-Bridged Six-Membered Metallacyclic Bis[(2-imida-zolyl)zirconocene] Dication. Z. Naturforsch., 58b, 305 - 310 (2003). V. V. Kotov, R. Fröhlich, G. Kehr, G. Erker: Synthesis and structural features of [(C5H4-CMe2NMe2)2TiCl], a bis(cyclopentadienyl)Ti(III) complex with internal dimethylamino coordination. J. Organomet. Chem., 676, 1 - 7 (2003). J. Heimann, H. J. Schäfer, R. Fröhlich, B. Wibbeling: Cathodic Cyclisation of N-(Oxoalkyl)pyridinium Salts - Formation of Tricyclic Indolizidine and Quinolizidine Derivatives inAqueous Medium. Eur. J. Org. Chem., 2919 - 2932 (2003). M. Tamm, B. Dreßel, Th. Lügger, R. Fröhlich, S. Grimme: Chelate Complexes of Functionalized Cycloheptatrienyl Ligands: Molybdenum Complexes with Linked Cycloheptatrienyl-Phosphane Ligands and Their Use in Catalytic Carbon-Carbon Bond Formation. Eur. J. Inorg. Chem., 1088 - 1098 (2003). O. Lukin, J. Recker, A. Böhmer, W. M. Müller, T. Kubota, Y. Okamoto, M. Nieger, R. Fröhlich, F. Vögtle: Eine topologisch chirale molekulare Hantel. Angew. Chem., 115, 458 - 461 (2003), Angew. Chem. Int. Ed., 42, 442 - 445 (2003). J. Cano Sierra, D. Hüerländer, M. Hill, G. Kehr, G. Erker, R. Fröhlich: Formation of Dinuclear Titanium and Zirconium Complexes by Olefin Metathesis - Catalytic Preparation of Organometallic Catalyst Systems. Chem. Eur. J., 9, 3618 - 3622 (2003). J. K. Eberhardt, R. Fröhlich, E.-U. Würthwein: N-Acylamidine Palladium(II) Com-plexes. Synthesis, Structures, and catalytic Activity for Suzuki-Miyaura Cross-Coupling Reactions: Experiments and DFT Calculations. J. Org. Chem., 68, 6690 - 6694 (2003). M. Albrecht, S. Schmid, M. deGroot, P. Weis, R. Fröhlich: Self-assembly of an unpolar enantiomerically pure helicate-type metalla-cryptand. Chem. Commun., 2526 - 2527 (2003). P. Liptau, L. Tebben, G. Kehr, B. Wibbeling, R. Fröhlich, G. Erker: Preparation of Optically Active a-Amino[3]ferrocenophanes - Building Blocks for Chelate Ligands in Asymmetric Catalysis. Eur. J. Inorg. Chem., 3590 - 3600 (2003). M. Hill, G. Kehr, R. Fröhlich, G. Erker: Organic Functional Group Transformations in the Periphery of a Group-4 Metallocene Complex: 2H-Pyrrole Formation at a Pendant Boron Lewis Acid. Eur. J. Inorg. Chem., 3583 - 3589 (2003). A. Snell, G. Kehr, B. Wibbeling, R. Fröhlich, G. Erker: Structural Features of a Sulfur-Containing Group 4 Metalla[11]-crown-4-Derivative. Z. Naturforsch., 58b, 838 - 842 (2003). D. Mirk, O.Kataeva, R. Fröhlich, S. R. Waldvogel: The First Direct Chlorination of Iodoarenes - A Side-Chain Directed Process. Synthesis, 2410 - 2414 (2003). A. Bierstedt, J. Roels, J. Zhang, Y. Wang, R. Fröhlich, P. Metz: A symmetry-based approach to the heterobicyclic core of the zaragozic acids - model studies in the C2-symmetric series. Tetrahedron Letters, 44, 7867 - 7870 (2003). M. Albrecht, I. Janser, S. Meyer, P. Weis, R. Fröhlich: A metallosupramolecular tetrahedron with a huge internal cavity. Chem. Commun., 2854 - 2855 (2003). M. C. Schopohl, K. Bergander, O. Kataeva, R. Fröhlich, S. R. Waldvogel: Synthesis and Characterization of Enantiomerically Pure Menthylamines and Their Isocyanates. Synthesis, 2689 - 2694 (2003). M. Tamm, A. Kunst, F. E. Hahn, T. Pape, R. Fröhlich: Biometallorganische Koordina-tionsverbindungen: Synthese und Strukutren von Übergangsmetallkomplexen mit Tropidinyl- und Tropidin-Liganden. Z. Anorg. Allg. Chem., 629, 2408 - 2414 (2003). D. Vagedes, G. Erker, G. Kehr, K. Bergander, O. Kataeva, R. Fröhlich, S. Grimme, C. Mück-Lichtenfeld: Tris(pentafluorophenyl)borane adducts of substituted imidazoles: conformational features and chemical behavior upon deprotonation. J. Chem. Soc., Dalton Trans., 1337 - 1344 (2003). S. Ünaldi, R. Aumann, R. Fröhlich: C-Cα Insertion: Insertion of an Alkyne into the C-C Single Bond between the Carbene-Carbon Atom and the a-Carbon Atom of a Fischer Carbene Complex by an Unprecedented Metalla(di-p-methane) Skeletal Rearrangement. Chem. Eur. J., 9, 3300 - 3309 (2003). P. Liptau, T. Seki, G. Kehr, A. Abele, R. Fröhlich, G. Erker, S. Grimme: Formation of a Chelate Bis(phosphino)[3]ferrocenophane Ligand and Ist Use in Palladium-Catalyzed Alternating CO/Ethene Copolymerization. Organometallics, 22, 2226 - 2232 (2003). C. Schultz-Fademrecht, M. Zimmermann, R. Fröhlich, D. Hoppe: Synthesis of Enantio-pure 2,5-Dihydro-3-iodofurans and Substituted 3-Iodofurans by Iodocyclization of 4-Hydroxy-1,2-alkadienyl Carbamates. Synlett, 1969 - 1972 (2003). A. Snell, G. Kehr, O. Kataeva, R. Fröhlich, G. Erker: Preparation and characterization of some structural variants of Cp*Ti(1,2-propandiolato)complexes. J. Organomet. Chem., 687, 171 - 177 (2003). B. Kramer, R. Fröhlich, S. R. Waldvogel: Oxidative Coupling Reactions Mediated By MoCl5 Leading to 2,2'-Cyclolignans: The Specific Role of HCl. Eur. J. Org. Chem., 3549 - 3554 (2003). M. Niehues, G. Kehr, R. Fröhlich, G. Erker: Generation and Structural Characterization of an [(Imidazol-2-ylidene)HfCl5]-Anion/Imidazolium Cation Salt. Z. Naturforsch., 58b, 1005 - 1008 (2003). E. Kh. Kazakova, A. V. Prosvirkin, V. V. Yanilkin, R. Fröhlich, W. D. Habicher: A Novel and Effective Strategy of Constructing of "Tube-Like" Double Resorcin[4]-arenes. J. Inclusion Phenom. Macrocyclic Chem., 47, 149 - 153 (2003). W.-H. Sun, T. Zhang, L. Wang, Y. Chen, R. Fröhlich: Supramolecular helical architecture assembled by double-helical [Ag2L2] units. J. Organomet. Chem., 689, 43 - 49 (2004). M. Albrecht, I. Janser, S. Kamptmann, P. Weis, B. Wibbeling, R. Fröhlich: Dicatechol-diimines:easily accessible ligands for the self-assembly of dinuclear triple-stranded helicates. J. Chem. Soc., Dalton Trans., 37 - 43 (2004). Th. Glaser, Th. Lügger, R. Fröhlich: Synthesis, Crystal Structures, and Magnetic Proper-ties of a Mono- and a Dinuclear Copper(II) Complex of the 2,4,6-Tris(2-pyridyl)-1,3,5-triazine Ligand. Eur. J. Inorg. Chem., 394 - 400 (2004). P. Liptau, M. Neumann, G. Erker, G. Kehr, R. Fröhlich, S. Grimme: Responsive Iron Neighboring Group Participation in Amino-Substituent-Stabilized [3]Ferrocenophane α-Carbenium Ions: A Combined Theoretical and Experimental Study. Organometallics, 23, 21 - 25 (2004). M. Tamm, Th. Bannenberg, R. Fröhlich, S. Grimme, M. Gerenkamp: Mono- and dinuclear molybdenum complexes with sterically demanding cycloheptatrienyl ligands. J. Chem. Soc., Dalton Trans., 482 - 491 (2004). W.-L. Nie, G. Erker, G. Kehr, R. Fröhlich: Bildung eines neuartigen ansa-Metallocen-Gerüsts durch intramolekulare photochemische [2+2]-Cycloaddition von Bis(2-alkenyl-indenyl)zirconium-Komplexen. Angew. Chem., 116, 313 - 317 (2004), Angew. Chem. Int. Ed., 43, 310 - 313 (2004). M. Seppi, R. Kalkofen, J. Reupohl, R. Fröhlich, D. Hoppe: Hoch enantiomerenangereicherte Keton-Homoenolat-Reagentien durch (-)-Spartein-vermittelte γ-Deprotonierung von achiralen 1-Alkenylcarbamaten. Angew. Chem., 116, 1447 - 1451 (2004), Angew. Chem. Int. Ed., 43, 1423 - 1427 (2004). J. Reuber, R. Fröhlich, D. Hoppe: Highly Enantioenriched Homoenolate Reagents by Asymmetric γ-Deprotonation of Achiral 1-Silyl-Substituted 1-Alkenyl Carbamates. Org. Letters, 6, 783 - 786 (2004). P. Becker, R. Fröhlich: Crystal Growth and Crystal Structure of the Metastable Bismuth Orthoborate BiBO3. Z. Naturforsch. 59b, 256 - 258 (2004). M. Hill, G. Kehr, G. Erker, O. Kataeva, R. Fröhlich: Formation of a bifunctional zirconocene complex that favours intramolecular -B(C6F5)2 addition to a Cp ring over σ-ligand abstraction. Chem. Commun., 1020 - 1021 (2004). G. Erker, G. Kehr, R. Fröhlich: Developing some functional group chemistry at the Group 4 bent metallocene frameworks. J. Organomet. Chem., 689, 1402 - 1412 (2004). M. Hogenbirk, G. Schat, O. S. Akkerman, F. Bickelhaupt, J. Schottek, M. Albrecht, R. Fröhlich, G. Kehr, G. Erker, H. Kooijman, A. L. Spek: (µ-Methylene)bis-(methylzirconocene): Preparation, Molecular Structure, and Thermal Disproportionation. Eur. J. Inorg. Chem., 1175 - 1182 (2004). M. Zimmermann, B. Wibbeling, D. Hoppe: Synthesis of Enantiomerically and Diastereomerically Pure 4-Hydroxy-1,2-alkadienyl Carbamates and Their Application in a Modified Nazarov Cyclization Towards Chiral Cyclopentenones. Synthesis, 765 - 774 (2004). K. Hegemann, R. Fröhlich, G. Haufe: Synthesis of Enantiopure 9-Oxabicyclononanediol Derivatives by Lipase-Catalyzed Transformations and Determination of Their Absolute Configuration. Eur. J. Org. Chem., 2181 - 2192 (2004). F. E. Hahn, Th. von Fehren, R. Fröhlich: The Ti(IV)Complex of a Benzannulated N-Heterocyclic Carbene. Z. Naturforsch. 59b, 348 - 350 (2004). F. E. Hahn, Th. von Fehren, L. Wittenbecher, R. Fröhlich: The Pd(II)Complex of a Bidentate Di(benzimidazol-2-ylidene) Ligand. Z. Naturforsch. 59b, 541 - 543 (2004). F. E. Hahn, Th. von Fehren, L. Wittenbecher, R. Fröhlich: Cleavage of a Dibenzotetraazafulvalene to Yield a Rh(I)Carbene Complex. Z. Naturforsch. 59b, 348 - 350 (2004). J. W. Strauch, J.-L. Fauré, St. Bredeau, C. Wang, G. Kehr, R. Fröhlich, H. Luftmann, G. Erker: (Butadiene)metallocene/B(C6F5)3 Pathway to Catalyst Systems for Stereoselective Methyl Methacrylate Polymerization: Evidence for an Anion Dependent Metallocene Catalyzed Polymerization Process. J. Am. Chem. Soc., 126, 2089 - 2104 (2004). G. Erker, G. Kehr, R. Fröhlich: The (Butadiene)zirconocenes and Related Compounds. Adv. Organomet. Chem. 51, 109 - 162 (2004). J. Cano Sierra, G. Kehr, R. Fröhlich, G. Erker: A Fulvene Route to Group 4 Metallocene Complexes Bearing 4,7-Bis(dimethylamino)-Substituted Indenyl Ligands. Eur. J. Inorg. Chem., 2260 - 2265 (2004). N. Habersaat, R. Fröhlich, E.-U. Würthwein: 4H-Imidazoles and Imidazoles from Anionic and Dipolar Electrocyclization Reactions of 2,4-Diazapenta-1,3-dienes. Eur. J. Org. Chem., 2567 - 2581 (2004). M. Albrecht, I. Janser, H. Houjou, R. Fröhlich: Long-Range Stereocontrol in the Self-Assembly of Two-Nanometer-Dimensioned Triple-Stranded Dinuclear Helicates. Chem. Eur. J., 10, 2839 - 2850 (2004). W. Iwanek, R. Fröhlich, V. Schurig: The Synthesis of Oxazaborolo-benzoxazaborinine Derivatives from Resorcinarene from (1S,2R)-ephedrine. J. Incl. Phenom. Macrocylic Chem. 49, 75-79 (2004). L. Tebben, G. Kehr, R. Fröhlich, G. Erker: The Synthesis of Optically Axtive Primary Amino[3]ferrocenophanes. Synthesis, 1971 - 1976 (2004). M. Albrecht, I. Janser, R. Fröhlich: Synthesis of Triscatechol Derivatives - Building Blocks with an Idealized C3-Symmetry for Metallo-Supramolecular Chemistry. Synthesis, 1977 - 1982 (2004). Th. Glaser, I. Liratzis, Th. Lügger, R. Fröhlich: Synthesis and Characterization of Ti Complexes Using 4-tert-Butyl-2,6-bis(hydroxymethyl)phenol: X-ray Strcutures of a Confacial Bioctahedron with Terminal Nucleophilic Phenylmethoxide Ligands, and a Ti4O16 Core Protected by Two Hydrophobic Binding Pockets. Eur. J. Inorg. Chem., 2683 - 2689 (2004). W. Steffen, T. Blömker, N. Kleigrewe, G. Kehr, R. Fröhlich, G. Erker: Generation of bis(iminoalkyl)pyridine cobalt(I) cations under metal alkyl free conditions that polymerize ethene. Chem. Commun., 1188 - 1189 (2004). K. Gerdes, P. Sagar, R. Fröhlich, B. Wibbeling, E.-U. Würthwein: 4,5-Dihydro-3H-benzo[c]azepines from 1,7-Electrocyclization Reactions of 2-Aza-4,5,-benzoheptatrienyllithium Compounds. Eur. J. Org. Chem., 3465 - 3476 (2004). D. Mirk, A. Willner, R. Fröhlich, S. R. Waldvogel: Iodinated Biaryls Synthesized by the Direct Dehydrodimerization of Iodoarenes Using Phenyliodine(III) Bis(trifluoroacetate) (PIFA). Adv. Synth. Catal., 346, 675 - 681 (2004). F. E. Hahn, M. Münder, R. Fröhlich: Homoleptic Nickel(0) Phenyl Isocyanide Complexes. Z. Naturforsch. 59b, 850 - 854 (2004). G. Unger, G. Erker, G. Kehr, R. Fröhlich: An Internally Coordinated Metalla[14]-crown-5 System with a Pentagonal-dipyramidal Coordination Geometry of the Central Titanium Atom. Z. Naturforsch. 59b, 917 - 920 (2004). S. Das, A. Pramanik, R. Fröhlich: Amarendra Patra. Facile acid-catalyzed condensation of 2-hydroxy-2,2'-biindan-1,1',3,3'-tetrone with phenols, methoxy-aromatic systems and enols. Tetrahedron 60, 10197 - 10205 (2004). D. M. Shendage, R. Fröhlich, G. Haufe: Highly Efficient Stereoconservative Amidation and Deamidation of α-Amino Acids. Org. Letters, 6, 3675- 3678 (2004). G. Erker, S. Venne-Dunker, G. Kehr, N. Kleigrewe, R. Fröhlich, Ch. Mück-Lichtenfeld, St. Grimme:Evidence for a Carbon-Carbon Coupling Reaction To Proceed through a Planar-Tetracoordinate Carbon Intermediate. Organometallics, 23, 4391 - 4395 (2004). M. Hill, G. Erker, G. Kehr, R. Fröhlich, O. Kataeva: Exploring CH-Activation Pathways in Bifunctional Zirconocene/Borane Systems. J. Am. Chem. Soc., 126, 11046 - 11057 (2004). F. E. Hahn, Ch. Ochs, Th. Lügger, R. Fröhlich: An Unsymmetrical Tripodal Ligand with NOS2-Donor Set: Coordination Chemistry with Nickel(II) and Zinc(II). Inorg. Chem. 43, 6101 - 6107 (2004). F. Hannig, R. Fröhlich, K. Bergander, G. Erker, J. L. Petersen: Structural and Spectroscopic Evidence for Intramolecular Agostic M...H-C and Dative ZrF-C(ortho) Interactions in the Zwitterionic Metal Complexes [(C5H4)SiMe2(N-t-Bu)]M(+)(µ-C4H6)B(-) (C6F5)3, M = Ti, Zr. Organometallics, 23, 4495- 4502 (2004). S. Behr, K. Hegemann, H. Schimanski, R. Fröhlich, G. Haufe: Synthesis of γ-Lactones from Cycloocta-1,5-diene - Starting Materials for Natural-Product Synthesis. Eur. J. Org. Chem., 3884 - 3892 (2004). G. Erker, G. Kehr, R. Fröhlich: Metallocene carbene chemistry. Russ. Chem. Bull., Int. Edit. 53, 1007 - 1019 (2004). P. Sagar, R. Fröhlich, E.-U. Würthwein: Eine vielseitige Aminobenzanellierungs-methode durch Deprotonierung von 2-(1-Alkinyl)benzaldiminen und ähnlichen 2-Aza-2,4-heptadienyl-6-inen: eine mehrstufige Umlagerungskaskade. Angew. Chem., 116, 5812 - 5815 (2004), Angew. Chem. Int. Ed., 43, 5694 - 5697 (2004). J. Merten, R. Fröhlich, P. Metz: Enantioselektive Totalsynthese der hoch oxygenierten1,10-seco-Eudesmanolide Eriolanin und Eriolangin. Angew. Chem., 116, 6117 - 6120 (2004), Angew. Chem. Int. Ed., 43, 5991 - 5994 (2004). M. Albrecht, I. Janser, J. Runsink, G. Raabe, P. Weis, R. Fröhlich: Selektion unterschiedlicher Spezies aus einer dynamischen kombinatorischen Bibliothek von Koordinationsverbindungen. Angew. Chem., 116, 6832 - 6836 (2004), Angew. Chem. Int. Ed., 43, 6662 - 6666 (2004). R. Kalkofen, S. Brandau, B. Wibbeling, D. Hoppe: Synthese von stereohomogenen Cyclopropancarbaldehyden und Cyclopropylketonen durch Cycloalkylierung von 4-Hydroxy-1-alkenylcarbamaten. Angew. Chem., 116, 6836 - 6838 (2004), Angew. Chem. Int. Ed., 43, 6667 - 6669 (2004). M. Albrecht, I. Janser, J. Fleischhauer, Y. Wang, G. Raabe, R. Fröhlich: An enantiomerically pure dinuclear triple-stranded helicate: X-ray structure, CD spectroscopy and DFT calculations. Mendeleev Comm. 14, 250 -253 (2004). C. Cornelißen, G. Erker, G. Kehr, R. Fröhlich: Formation and reactions of metal-metal bonded heterobimetallic (C5H4PR2)-bridged (Zr-Ir) and (Zr-Rh) complexes: evidence for the participation of metal hydride intermediates. J. Chem. Soc., Dalton Trans., 4059 - 4063 (2004). G. Erker, G. Kehr, R. Fröhlich: Some selected chapters from the (butadiene)-zirconocene story. J. Organomet. Chem., 689, 4305 - 4318 (2004). L. R. Chadwick, D. Nikolic, J. E. Burdette, C. R. Overk, J. L. Bolton, R. B. van Breemen, R. Fröhlich, H. H.S. Fong, N. R. Farnsworth, G. F. Pauli: Estrogens and Congeners from Spent Hops (Humulus lupulus). J. Nat. Prod. 67, 2024 - 2032 (2004). M. Özlügedik, J. Kristensen, J. Reuber, R. Fröhlich, D. Hoppe: Stereoselective Synthesis of Highly Substituted Bicylic γ-Lactones Using Homoaldol Addition of 1-(1-Cycloalkenyl)methyl Carbamates. Synthesis, 2303 - 2316 (2004). I. Bauer, G. G. Sergeenko, I. S. Nizamov, G. Theumer, R. Fröhlich, A. R. Burilov, V. I. Maslennikova, W. D. Habicher: Synthesis of in,out-isomeric phosphite and phosphate cryptands. ARKIVOC, 38-46 (2004). Th. C. Rosen, S. Yoshida, R. Fröhlich, K. L. Kirk, G. Haufe: Fluorinated Phenylcyclopropylamines. 2. Effects of Aromatic Ring Substitution and of Absolute Configuration on Inhibition of Microbial Tyramine Oxidase. J. Med. Chem. 47, 5860 - 5871 (2004). D. Mirk, B. Wibbeling, R. Fröhlich, S. R. Waldvogel: Oxidative Coupling of Alkylated Anisole Derivatives Using MoCl5. Synlett, 1970 - 1974 (2004). N. Gudimalla, R. Fröhlich, D. Hoppe: Stereoselective Synthesis of Baylis-Hillman Type Adducts via Allenolates Generated by Acyl Migration. Org. Letters, 6, 4005 - 4008 (2004). C. Cornelißen, G. Erker, G. Kehr, R. Fröhlich: Formation and Structure of a Bis(Cyclopentadienyl)(formamidinato)zirconium Cation Complex. Z. Naturforsch. 59b, 1246 - 1252 (2004). M. Albrecht, I. Janser, R. Fröhlich: Catechol imine ligands: from helicates to supramolecular tetrahedra. Chem. Comm., 157 - 165 (2005). A. Dutt, R. Fröhlich, A. Pramanik: -Turn mimic in tripeptide with Phe(1)-Aib(2) as corner residues and β-strand structure in an isomeric tripeptide: an X-ray diffraction study. J. Chem. Soc., Org. Biomol. Chem., 661 - 665 (2005). X. Tian, M. Woski, Ch. Lustig, T. Pape, R. Fröhlich, D. Le Van, K. Bergander, N. W. Mitzel: N,N-Diisopropylaminomethyllithium: Synthesis, Oxidative Degradation, and Organoaluminium and -gallium Derivatives. Organometallics, 24, 82 - 88 (2005). V. N. Kovtonyuk, L. S. Kobrina, O. Kataeva, G. Haufe: Formation of Fluorinated 1-Oxaspiro[2.5]octa-4,7-dienes from Polyfluorinated Cyclohexa-2,5-dienones with Diazomethane and Reactions with Aryl and 2-Chloroethyl Isocyanates. Eur. J. Org. Chem., 1178 - 1183 (2005). St. Knüppel, C. Wang, G. Kehr, R. Fröhlich, G. Erker: Bis(enamino-Cp) Group 4 metal complex chemistry: developing a Mannich-Type carbon-carbon coupling reaction at the bent metallocene framework. . J. Organomet. Chem., 690, 14 - 32 (2005). N. Gudimalla, R. Fröhlich, D. Hoppe: A Simple and Practical Approach to α-Halo- and α-Phenylthio-α,β-Enones. Synthesis, 415 - 418 (2005). D. M. Shendage, R. Fröhlich, K. Bergander, G. Haufe: Asymmetric Synthesis of γ-Fluorinated α-Amino Acid Derivatives. . J. Org.  Chem., 719 - 727 (2005). Xin Tian, Roland Fröhlich, Norbert W. Mitzel: Organoaluminium and -gallium compounds with N,N-diiospropylaminomethyl groups. J. Chem. Soc., Dalton Trans., 380 - 3084 (2005). X. Tian, R. Fröhlich, N. W. Mitzel: A Gallium-Nitrogen Heteronorbornane with Bulky tButyl Substituents. Z. Naturforsch. 60b, 243 - 246 (2005). X. Tian, R. Fröhlich, N. W. Mitzel: The Crystal Structures of Dimeric Di(tert-butyl)aluminium and -gallium Iodides. Z. Naturforsch. 60b, 247 - 250 (2005). S. Ye, S. Yoshida, R. Fröhlich, G. Haufe, K. L. Kirk: Fluorinated phenylcyclopropyl-amines. Part 4: Effects of aryl substituents and stereochemistry on the inhibition of monoamime oxidases by 1-aryl-2fluoro-cyclopropylamines. Bioorg. Med. 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