Fachbereich 12 - Chemie und Pharmazie
Organisch-Chemisches Institut
Fachbereichsprojekte

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 three hundred X-ray structures per year, ready for publication. It is also involved in the teaching of graduate or doctoral students.

Veröffentlichungen:

P. Becker, R. Fröhlich: Crystal structure of trisodium gallium borate, Na₃GaB₄O₉, a new anhydrous borate structure type. Z. Kristallogr. NCS, 216, 31-32 (2001).

H.-P. Wu, R. Aumann, R. Fröhlich, P. Saarenketo: “Dimers“ and “Trimers“ of Tetrahydroindenes and Hexahydroazulenes, Respectively Generated from [2-(1-Cycloalkenyl)ethynyl]carbene Complexes (M = Cr, W) by Cascade Cyclization/Cycloaddition Reactions. Chem. Eur. J., 7, 700-710 (2001).

R. Aumann, I. Göttker-Schnetmann, R. Fröhlich, P. Saarenketo, C. Holst: Enaminone Substituents Attached to Cyclopentadienes: 3E/3Z Stereochemistry of 1-Metalla-1,3,5-hexatriene Intermediates (M = Cr, W) as a Functional Criterion for the Formation of Cyclopentadienes and Six-Membered Heterocycles, Respectively. Chem. Eur. J., 7, 711-720 (2001).

O. Maier, R. Fröhlich, E.-U. Würthwein: Polydonor-Substituted 1-Oxa- and 1-Thia-3,5-diazahexatrienes: Synthesis, Structures, Ring-Chain Tautomerism and Theoretical Calculations. Eur. J. Org. Chem., 83-92 (2001).

M. Brüggemann, C. Holst, D. Hoppe: First Enantioselective Total Synthesis of Both (+)- and (-)-Metachromin A. Eur. J. Org. Chem., 647-654 (2001).

O. Stratmann, B. Kaiser, R. Fröhlich, O. Meyer, D. Hoppe: Configurational Stability of an Enantioenriched a-Thiobenzyllithium Derivative and Stereochemical Course of Its Electrophilic Substitution Reactions. Synthesis of Enantiomerically Pure Tertiary Benzylic Thiols. Chem. Eur. J., 7, 423-435 (2001).

G. Kehr, R. Roesmann, R. Fröhlich, C. Holst, G. Erker: Protonation of the Heterocyclic Cp-Anion Equivalent [Pyrrolyl-B(C₆F₅)₃]Li Formation of a Useful Neutral Brønsted Acid for the Generation of Homogeneous Metallocene Ziegler Catalysts. Eur. J. Inorg. Chem., 535-538 (2001).

R. Aumann, K. Roths, R. Fröhlich: Rearrangment of carbiminium carbonyl metalate by mutual exchange of alkoxy- and amino functionalities (M = W, Cr). ).J. Organomet. Chem., 617-618, 322-328 (2001).

F. E. Hahn, L. Wittenbecher, M. Kühn, T. Lügger, R. Fröhlich: A zwitterionic carbene-stannylene adduct via cleavage of a dibenzotetraazafulvene by a stannylene. J. Organomet. Chem., 617-618, 629-634 (2001).

M. Tamm, T. Bannenberg, A. Grzegorzewski, R. Fröhlich: 2-Azaallenylidene complexes: syntheses and structures of chromium and tungsten complexes with a (cyclopropenylidene)-2-azaethenylidene ligand. J. Organomet. Chem., 617-618, 640-646 (2001).

M. Abrecht, M. Napp, M. Schneider, P.Weis, R. Fröhlich: Kinetic versus thermo-dynamic control of the self-assembly of isomeric double-stranded dinuclear titanium(IV) complexes from a phenylalanine-bridged dicatechol ligand. Chem. Commun., 409-410 (2001).

K. Kunz, G. Erker, G. Kehr, R. Fröhlich: Synthesis and Structural and Chemical Features of Formimidoyl-Functionalized Lithium Cyclopentadienides. Organo-metallics, 20, 392-400 (2001).

D. Kunz, R. Fröhlich, G. Erker: Preparation and Structural Features of Lithium Cyclopentadienides that Contain Amino Acid-Derived Cp-Substituents. Organo-metallics, 20, 572-574 (2001).

M. Tamm, T. Bannenberg, B. Dressel, R. Fröhlich, D. Kunz: Molybdenum Complexes of Sterically Demanding Cycloheptatrienyl Ligands. Organometallics, 20, 900-904 (2001).

M. Tamm, K. Baum, R. Fröhlich, P. Saarenketo: Synthesis and Reactivity of Doubly Bridged m-h₅:h7-Cyclopentadienylcycloheptatrienyl Dimolybdenum Complexes. Organo-metallics, 20, 1376-1386 (2001).

H. Laqua, R. Fröhlich, B. Wibbeling, D. Hoppe: Synthesis of enantioenriched indene-derived bicyclic alcohols and tricyclic cyclopropanes via (-)-spaeteine-mediated lithiation of a racemic precursor and kinetic resolution during the cyclocarbolithiation. J. Organomet. Chem., 621, 96-104 (2001).

T. Dreier, G. Unger, G. Erker, B. Wibbeling, R. Fröhlich: Group 4 metallocenes containing substituents at their Ð-ligands: synthesis and characterization of the parent bis[2-(2-furyl)indenyl]zirconocene system. J. Organomet. Chem., 622, 143-148 (2001).

C. Held, R. Fröhlich, P. Metz: Enantioselektive Synthese des Ricciocarpine A und B. Angew. Chem., 113, 1091 1093 (2001); Angew. Chem. Int. Ed., 40, 1058 - 1060 (2001).

N. B. Singh., A. Srivastava, R. Fröhlich: Single crystal formation by solid state reaction between 8-hydroxychinoline and 2,4,5-trichlorophenol. J. Chem. Soc., Perkin Trans. 2, 838-842 (2001).

N. Kleigrewe. T. Brackemeyer, G. Kehr, R. Fröhlich, G. Erker: Synthesis and Structural Behavior of the Tris(h-cyclopentadienyl)zirconium Betaine Complex Cp₂[h⁵-C₅H₄B(C₆F₅ )₃]Zr. Organometallics, 20, 1952-1955 (2001).

L. Peters, R. Fröhlich, A. S. F. Boyd, A. Kraft: Noncovalent Interactions between Tetrazole and an N,N'-Diethyl-Substituted Benzamidine. J. Org. Chem., 66, 3291- 3298 (2001).

C. Schultz-Fademrecht, B. Wibbeling, R. Fröhlich, D. Hoppe: Synthesis of Enantiomerically Enriched Allenes by (-)-Sparteine-Mediated Lithiation of Alkynyl Carbamates. Org. Letters, 3, 1221-1224 (2001).

T. Dreier, R. Fröhlich, G. Erker: Preparation and structural features of 1-(2-pyridyl)- and 1-(2-furyl)indenyl-zirconium complexes. J. Organomet. Chem., 621, 197-206 (2001).

H.-P. Wu, R. Aumann, R. Fröhlich, E. Wegelius: A Convenient Regio- and Stereoselective Approach to the Angular Allylation of Bicyclic Cyclopentadienes Generated by the (1-Alkynyl)carbene Complex Route. Organometallics, 20, 2183-2190 (2001).

I. Göttker-Schnetmann, R. Aumann, O. Kataeva, C. Holst, R. Fröhlich: Spiro-Fused Cyclopentadienes and Novel Pyridinium Carbonyltungstates from (1-Alkynyl)carbene Tungsten Complexes and exo-Methylene N-Heterocycles. Competition between 1,4-Addition, 1,2-Addition, and Metathesis. Organometallics, 20, 2889-2904 (2001).

A. Reichert, R. Fröhlich, R. Ferguson, A. Kraft: Binding Interactions between 3-aryl-1,2,4-oxadiazol-5-ones and a trisimidazoline base. J. Chem. Soc., Perkin Trans. 1, 1321-1328 (2001).

D. Alickmann, R. Fröhlich, E.-U. Würthwein: Base-Induced Heterochiral Dimerization of an Oxiranyl Carbaldimine: Stereoselective Synthesis of a Highly Functionalized Aziridine. Org. Letters, 3, 1527-1530 (2001).

K. Kunz, G. Erker, St. Döring, R. Fröhlich, G. Kehr: Generation of Homogeneous (sp³-C₁)-Bridged Cp/Amido and Cp/Phosphido Group 4 Metal Ziegler-Natta Catalyst Systems. J. Am. Chem. Soc., 123, 6181-6182 (2001).

M. Essers, B. Wibbeling, G. Haufe: Synthesis of the first fluorinated cantharidin analogues. Tetrahedron Lett., 42, 5249-5433 (2001). M.Albrecht, K. Witt, H. Röttele, R. Fröhlich: Stereoselective formation of a trinuclear hexa-stranded helicate-type zinc(II) complex. Chem. Commun., 1330-1331 (2001).

M. Plitzner, U. Heinl, R. Mattes, R. Fröhlich: Struktur eines Blei(II)-Komplexes mit verknüpften Monothioquadratationen als Liganden. Z. Anorg. Allgem. Chem., 627, 1426 - 1428 (2001).

T. Jödicke, F. Menges, G. Kehr, G. Erker, U. Höweler, R. Fröhlich: Conformational Features of Group-4 ansa-Metallocenes with Long (CH₂)_n-Chains Connecting Their Cyclopentadienyl Ligands. Eur. J. Inorg. Chem., 2097 - 2106 (2001).

P. Vossmann, K. Hornig, R. Fröhlich, E.-U. Würthwein: Asymmetric Addition of Aldehydes and Ketones to Chiral 2-Azapentadienyl Lithium Compounds: Diastereo-selective Synthesis of 4-Vinyl-4,5-dihydro-oxazoles. Synthesis, 1415-1426 (2001).

H. Bernsmann, M. Gruner, R. Fröhlich, P. Metz: A shortcut to the smaller fragment of pamamycin-607. Tetrahedron Lett., 42, 5337-5390 (2001).

M. Albrecht, M. Napp, M. Schneider, P. Weis, R. Fröhlich: Dinuclear Titanium(IV) Complexes from Amino Acid Bridged Dicatechol Ligands: Foramtion, Structure, and Conformational Analysis. Chem. Eur. J., 7, 3966-3975 (2001).

C. Ochs, F. E. Hahn, R. Fröhlich: Coordination Chemistry of Unsymmetrical Tripodal Ligands with NNO2 Donor Set. Eur. J. Inorg. Chem., 2427 - 2436 (2001).

A. Deiters, B. Wibbeling, D. Hoppe: Enantio- and Diastereoselective Synthesis of a 3,4-Divinylpyrrolidine via Asymmetric Deprotonation and Cyclization of a 9-Chloro-5-aza-2,7-nonadiene. Adv. Synth. Catal., 343, 181-183 (2001).

F.E. Hahn, D. Le Van, M. C. Moyes, T. von Fehren, R. Fröhlich, E.-U. Würthwein: Ungewöhnliche Boldung eines Azaphospholens aus 1,3,4,5-Tetramethylimidazol-2-yliden und Diisopropylaminophosphaethin. Angew. Chem., 113, 3241 3244 (2001); Angew. Chem. Int. Ed., 40, 3144-3148 (2001).

D. Kunz, R. Fröhlich, G. Erker: Structural Features of Primary 6-Aminopentafulvenes and Some of Their Derivatives. Eur. J. Org. Chem., 3531 - 3536 (2001).

B. Plietker, D. Seng, R. Fröhlich, P. Metz: Synthesis of Highly Substituted Methylene-cyclohexenes Using New Domino Reactions with Sultones. Eur. J. Org. Chem., 3669 - 3676 (2001).

S. Kratschmer, H. J. Schäfer, R. Fröhlich: Cathodically initiated cyclodimerization of trimethyl aconitate. J. Electroanal. Chem., 507, 2-10 (2001).

T. Gerkensmeier, C. Agena, W. Iwanek, R. Fröhlich, S. Kotila, C. Mäther, J. Mattay: Synthesis and Structural Studies of 5,11,17,23-Tetrahydroxyresorc[4]arenes. Z. Naturforsch. 56b, 1063-1073 (2001).

Q. Y. Li, A. H. Parham, M. Nieger, M. Bolte, R. Fröhlich, P. Saarenketo, K. Rissanen, F. Vögtle: Synthesis and X-ray Strcuture of Amide-Based Macrocycles, Catenanes and Pretzelane. Eur. J. Org. Chem., 4041 - 4049 (2001).

A. Kraft, L. Peters, S. Johann, A. Reichert, F. Osterod, R. Fröhlich: Noncovalent interactions between acidic heterocycles and amidine bases. Mat. Science & Engineering, C18, 9-13 (2001).

M. Albrecht, J. Zauner, R. Burgert, H. Röttele, R. Fröhlich: Synthesis of tweezer-type receptors for the recognition of anions: observation of an additive effect of hydrogen bonds on nitrate binding. Mat. Science & Engineering, C18, 185-190 (2001).

H.-P. Wu, R. Aumann, R. Fröhlich, B. Wibbeling, O. Kataeva: Highly Selective Formation of [4+2] and [4+3] Cycloadducts of Tetrahydroindenes Generated in Situ from a (1-Alkynyl)carbene Tungsten Complex by the Metalla-1,3,5-hexatriene Route. Chem. Eur. J., 7, 5084-5093 (2001).

T. Dreier, K. Bergander, E. Wegelius, R. Fröhlich, G. Erker: Structural and DynamicFeatures of Bis[2-[2-furyl)indenyl]zirconium Derivatives. Organometallics, 20, 5067-5075 (2001).

D. Witthaut, R. Fröhlich, H.J. Schäfer: Heterocyclen durch Dominoreaktionen mit Aconitsäuremethylester, einem vileseitigen Synthesebaustein. Angew. Chem., 113, 4354 4356 (2001); Angew. Chem. Int. Ed., 40, 4212-4214 (2001).

P. Liptau, S. Knüppel, G. Kehr, O. Kataeva, R. Fröhlich, G. Erker: Formation and structural characterization of amino-substituted [3]ferrocenophanes derived from intramolecular Mannich-type coupling ractions at the metallocene framework.. J. Organomet. Chem., 637-639, 621 630 (2001).

B. Temme, J. Karl, M. Dahlmann, K. Bergander, G. Kehr, H. Luftmann, R. Fröhlich, T. Jödicke, G. Erker: The Development of Single Component Metallocene Betaine Ziegler-Natta Catalysts and Related Systems, in: Advances in Oraganometallic Catalysts and Olefin Polymerization in China and Germany, edited by J. Sun and C. Janiak, Chemical Industry Press, Beijing, 2001.

A. Bierstedt, J. Stölting, R. Fröhlich, P. Metz: Enzymatic kinetic resolution of 1-(3'-furyl)-3-buten-1-ol and 2-(2'-furyl)-propan-1-ol. Tetrahedron Asymmetry, 12, 3399-3407 (2001).

M. Brüggemann, R. Fröhlich, B. Wibbeling, C. Holst, D. Hoppe: Stereoselective formation of quaternary carbon centres with chiral 3-sulfonyl-1,3-oxazolidines and titanium enolates. Tetrahedron, 58, 321 340 (2002).

H.-P. Wu, R. Aumann, R. Fröhlich, E. Wegelius: Bicyclic Cyclopentadienes with N,S Substituents. Eur. J. Org. Chem., 361 - 368 (2002).

D. Vagedes, G. Erker, R. Fröhlich: Synthesis and structural characterization of [H(OEt₂)₂]₊[(C₃H ₃N₂){B(C₆F₅)₃}₂]- - a Brønsted acid with an imidazole-derived 'non-coordinating' anion. J. Organomet. Chem., 641, 148-155 (2002).

M. Albrecht, K. Witt, R. Fröhlich, O. Kataeva: Inter- and intramolecular hydrogen bonding in amide- and urea-substituted 8-hydroxyquinoline derivatives. Tetrahedron, 58, 561-567 (2002).

M. Tamm, T. Bannenberg, B. Dressel, R. Fröhlich, C.Holst: Molybdenum Complexes with Linked Cycloheptatrienyl-Phenolate Ligands. Inorg. Chem., 41, 47 59 (2002).

H.-P. Wu, R. Aumann, R. Fröhlich, B. Wibbeling. Stereocontrolled Synthesis of Angularly Fused Tricyclic Ring Systems by Means of 1-Metalla-1,3,5-hexatrienes (M = Cr, W). Chem. Eur. J., 8, 910-916 (2002).

M. Özlügedik, J. Kristensen, B. Wibbeling, R. Fröhlich, D. Hoppe. Nonracemic, Chiral Homoenolate Reagents Derived from (Cycloalk-1-enyl)methyl Carbamates and Evaluation of Their Configurational Stabilities. Eur. J. Org. Chem., 414 - 427 (2002).

C. Schultz-Fademrecht, M. A. Tius, S. Grimme, B. Wibbeling, D. Hoppe. Synthesis of Enantioenriched 5-Alkylidene-2-cyclopentenones from Chiral Allenyl Carbamates: Generation of a Chiral Lithium Allenolate and Allylic Activation for a Conrotatory 4p-Electrocyclization. Angew. Chem., 114, 1610-1612 (2002); Angew. Chem. Int. Ed., 41, 1532-1535 (2002).

S. Döring, G. Erker, R. Fröhlich. Synthesis of dimetallic µ-alkylideneamido zirconocene dications by a thermodynamically favorable lithium chloride elimination pathway. J. Organomet. Chem., 643 - 644, 61 67 (2002).

K. Kunz, G. Erker, G. Kehr, R. Fröhlich, H. Jacobsen, H. Berke, O. Blacque. Formation of Cyclodimeric (sp₂-C₁)-Bridged Cp/-Oxido (“CpC₁O“M^IVX₂) Group 4 Metal Ziegler-Natta Catalyst Systems How Important Is the “Constrained Geometry“ Effect? J. Am. Chem. Soc., 124, 3316-3326 (2002).

A. Kraft, L. Peters, R. Fröhlich. N.N',N'',N'''-Tetraethylterephtal-amidinium bis(tetrazolate). Acta Cryst. C58, o272-o274 (2002).

M. Tamm, K. Baum, T. Lügger, R. Fröhlich, K. Bergander. Chelate Complexes of Functionalized Cycloheptatrienyl Ligands: 17- and 18-Electron Molybdenum Complexes with Linked Cycloheptatrienyl-Phosphane Ligands and Their Use in Transition Metal Catalysis. Eur. J. Inorg. Chem., 918 - 928 (2002).

F. E. Hahn, D. Le Van, L. Wittenbecher, M.C. Moyes, T. Von Fehren, R. Fröhlich, E.-U. Würthwein. Novel 1,2,4-Triphosphole, 1,2,3-Triphosphetene and Azaphospholene Derivatives from N-Heterocyclic Carbenes and Phosphaalkynes. Phosphorus, Sulfur and Silicon, 177, 1863-1867 (2002).

R. Aumann, D. Vogt, X. Fu, R. Fröhlich, P. Schwab. Carbocyclic Four-, Five-, and Six-Membered Rings by Condensation of (Alkyl,ethoxy)carbene Complexes (M = W, Cr) with á,â-Unsaturated Tertiary Acid Amines. Organometallics, 21, 1637-1645 (2002).

G. Gralla, B. Wibbeling, D. Hoppe. Synthesis of an Ethynyl Carbamate and Application for Enantioselective Cyclocarbolithiation. Org. Lett., 4, 2193-2195 (2002).

R. Aumann, D. Vogt, R. Fröhlich. 3-Aza-1-metalla-1,3,5-hexatrienes (M = Cr, W): Generation and p-Cyclization to Pyrroles. Organometallics, 21, 1819-1824 (2002).

A. Deiters, C. Mück-Lichtenfeld, R. Fröhlich, D. Hoppe. Planar-Chiral (2E,7Z)- and (2Z,7E)-Cyclonona-2,7-dien-1-yl Carbamates by Asymmetric, Bis-Allylic á,á'-Cycloalkylation Studies on Their Conformational Stability. Chem. Eur. J., 8, 1833-1842 (2002).

U. Heinl, P. Hinse, R. Fröhlich, R. Mattes. Monomere und polymere Dimethylamino-thioquadratato-Komplexe: Die Kristallstrukturen von Nickel(II)-, Cobalt(II)-, Silber(I)-, Platin(II)-, Gold(I)-, Quecksilber(II)- und Blei(II)-Dimethylaminothioquadrataten. Z. Anorg. Allg. Chem., 628, 770-778 (2002).

B. Jaki, O. Sticher, M. Veit, R. Fröhlich, G. F. Pauli. Evaluation of Glucoiberin Reference Material from Iberis amara by Spectroscopic Fingerprinting. J. Nat. Prod., 65, 517-522 (2002).

D. Hüerländer, R. Fröhlich, G. Erker. Synthesis and structural characterization of Group 4 metallocene complexes that contain remote carboxamide functionalities at their Cp-side chains. J. Chem. Soc., Daltons Trans., 1513-1520 (2002).

K. Kunz, G. Erker, S. Döring, S. Bredeau, G. Kehr, R. Fröhlich. Formation of sp³-C₁-Bridged Cp/Amido Titanium and Zirconium “CpCN“ Constrained-Geometry Ziegler-Natta catalyst Systems. Organometallics, 21, 1031-1041 (2002).

J. G. Peters, M. Seppi, R. Fröhlich, B. Wibbeling, D. Hoppe. Stereoselective Intermolecular Carbolithiation of Open-Chain and Cyclic 1-Aryl-1-alkenyl N,N-Diisopropylcarbamates Coupled with Electrophilic Substitution. Observation of p-Carboxylation in a Benzyllithium Derivative. Synthesis, 381-392 (2002).

G. Haufe, D. Wölker, R. Fröhlich. Selectivity of Biohydroxylation with Beauveria bassiana of trans-2-Fluorocycloalkyl N-Phenylcarbamates. J. Org. Chem., 67, 3022-3028 (2002).

G. Haufe, T. Rosen, O. G. J. Meyer, R. Fröhlich, K. Rissanen. Synthesis, reactions and structural features of monofluorinated cyclopropanecarboxylates. J. Fluorine Chem., 114, 189-198 (2002).

S. R. Waldvogel, E. Aits, C. Holst, R. Fröhlich. Dehydrodimerization of iodobenzenes to iodinated biaryls. Chem. Commun., 1278-1279 (2002).

T. Glaser, M. Gerenkamp, R. Fröhlich. Gezielte Synthese von ferromagnetisch gekoppelten Komplexen mit modifizierten 1,3,5-Trihydroxybenzolliganden. Angew. Chem., 114, 3984 3986 (2002); Angew. Chem. Int. Ed., 41, 3823-3825 (2002).

M. Albrecht, O. Blau, R. Fröhlich. “Size-selectivity“ in the template-directed assembly of dinuclear triple-stranded helicates. Proc. Natl. Acad. Sci. USA, 99, 4867-4872 (2002).

V. O. Rogatchov, H. Bernsmann, P.Schwab, R. Fröhlich, B. Wibbeling, P. Metz. Preparation of enantiopure sultams by intramolecular Diels-Alder reaction of furan-containing vinylsulfonamides. Tetrahedron Letters, 43, 4753-4756 (2002).

H. Bernsmann, Y. Wang, R. Fröhlich, P. Metz. Amino analogs of actic acids synthesis and lactamization. Tetrahedron, 58, 4451-4457 (2002).

D. Vagedes, G. Kehr, D. König, K. Wedeking, R. Fröhlich, G. Erker, C. Mück-Lichtenfeld, S. Grimme. Formation of Isomeric BAr₃ Adducts of 2-Lithio-N-methylimidazole. Eur. J. Inorg. Chem., 2015 - 2021 (2002).

J. W. Strauch, G. Erker, G. Kehr, R. Fröhlich. Bildung eines zwitterionischen Einkomponentenkatalysators für die Ethenpolymerisation auf Basis von Butadiennickelkomplexen: ein alternativer Aktivierungsweg bei homogenen Ziegler-Natta-Katalysatoren später Übergangsmetalle. Angew. Chem., 114, 2662 2664 (2002); Angew. Chem. Int. Ed., 41, 2543-2545 (2002).

N. B. Singh, A. Pathak, R. Fröhlich. Single Crystal Formation by Solid-State Reaction between p-Benzoquinone and 2,4,5-Trichlorophenol. Aust. J. Chem., 55, 271-273 (2002).

M. Oelgemöller, C. Schiel, R. Fröhlich, J. Mattay. The “Photo-Friedel-Crafts Acylation“ of 1,4-Naphthoquinones. Eur. J. Org. Chem., 2465 - 2474 (2002).

T. Dreier, F. Hannig, G. Erker, K. Bergander, R. Fröhlich. Conformational features of a furyl-substituted bis(tetrahydroindenyl)zirconium dichloide system. J. Phys. Org. Chem., 15, 582-589 (2002).

C. Held, R. Fröhlich, P. Metz. Enantioselective Synthesis of the Molluscicidal Furanosesquiterpene Lactones Ricciocarpin A and Ricciocarpin B via Ring Closing Metathesis. Adv. Synth. Catal., 344, 720-727 (2002).

M. Albrecht, J. Zauner, R. Fröhlich, O. Kataeva, E. Wegelius, K. Rissanen. Tweezer-Type Catechol and Resorcinol Derivatives: Preparation, Structures, and First Investigations Towards their Hydrogen Bonding Abilities. Synthesis, 1434-1444 (2002).

D. Hüerländer, N. Kleigrewe, G. Kehr, G. Erker, R. Fröhlich. Synthesis, Structural and Chemical Characterization of Unsaturated C₄- and C₁₀-Bridged Group-4 ansa-Metallocenes Obtained Through a Ring-Closing Olefin Metathesis Reaction. Eur. J. Inorg. Chem., 2633 - 2642 (2002).

C. Höltke, G. Erker, G. Kehr, R. Fröhlich, O. Kataeva. The Reaction of (Butadiene)zirconocene with Imines. Eur. J. Inorg. Chem., 2789 - 2799 (2002).

S. Courtenay, S. Smith, E. Hollink, U. Blaschke, G. Kehr, R. Fröhlich, G. Erker, D. W. Stephan. Synthesis of a Dinuclear µ-(ç₂-Thioaldehyde)zirconocene Cation Complex. Z. Naturforsch., 57b, 1184-1188 (2002).

D. Harmsen, G. Erker, R. Fröhlich, G. Kehr. Reaction of [(Cp₂TiCH₃)(THF)⁺][BPh₄-] with Tripeptide Derivatives: Formation of Cationic (Peptide)titanocene Complexes. Eur. J. Inorg. Chem., 3156 - 3171 (2002).

B. Chankvetadze, N. Burjanadze, J. Breitkreuz, K. Bergander, D. Bergenthal, O. Kataeva, R. Fröhlich, H. Luftmann, G. Blaschke. Mechanistic study of the opposite migration order of the enantiomers of ketamine wit á- and â-cyclodextrin incapillary electrophoresis. J. Sep. Sci., 25, 1155- 1166 (2002).

W. Iwanek, R. Fröhlich, P. Schwab, V. Schurig. The synthesis and crystallographic structures of novel bora-oxazino-oxazolidine derivatives of resorcarene. Chem. Commun., 2516-2517 (2002).

C. Ludovici, R. Fröhlich, K. Vogtt, B. Mamatt, M. Lübben. Caged O₂ Reaction of cytochrome bo₃ oxidase with photochemically released dioxygen from a cobalt peroxocomplex. Eur. J. Biochem., 269, 2630-2637 (2002).

I. Bauer, R. Fröhlich, A. Y. Ziganshina, A. V. Prosvirkin, M. Gruner, E. Kh. Kazakova, W. D. Habicher. Synthesis and Structural Peculiarities of Homeomorphic Phosphorus Bridgehead Macrobicyclic Compounds and Novel Dioxaphospha [3.1.1.]p,m,p-cyclophanes. Chem. Eur. J., 8, 5622-5629 (2002).

F. Marr, R. Fröhlich, D. Hoppe. Preparation of meso-1,3-diphenylallyllithium.(-)-sparteine its crystal structure and reactions. Tetrahedron Asymmetry, 13, 2587-2592 (2002).

M. Albrecht, K. Witt, P. Weis, E. Wegelius, R. Fröhlich. Zinc(II)complexes of amide- and urea-substituted 8-hydroxyquinolines. Inorg. Chim. Acta, 341, 25-32 (2002).

M. Niehues, G. Kehr, G. Erker, B. Wibbeling, R. Fröhlich, O. Blacque, H. Berke. Structural characterization of Group 4 transition metal halide bis-Arduengo carbene complexes MCl₄L₂: X-ray crystal structure analyses and DFT calculations. J. Organomet. Chem., 663, 192-203 (2002).

F. Marr, R. Fröhlich, B. Wibbeling, C. Diedrich, D. Hoppe. The Synthesis and Configurational Stability of Enantioenriched a-Thioallyllithium Compounds and the Stereochemical Course of Their Electrophilic Substitutions. Eur. J. Org. Chem., 2970-2988 (2002).

D. Alickmann, R. Fröhlich, A. H. Maulitz, E.-U. Würthwein. Electrocyclization Reactions of 1-Aza-and 1-Oxa-pentadienyl- and heptatrienyl Cations: Synthesis of Pyrrole and Furan Derivatives. Eur. J. Org. Chem., 1523-1537 (2002).

R. Aumann, X. Fu, D. Vogt, R. Fröhlich, O. Kataeva. Retro-Fischer Reaction Induced by a b-Imino Functionality of (Alkyl,ethoxy)carbene Complexes (M = W, Cr): Efficient Access to C-Enamino und N-Enamino Carbene Complexes. Organometallics, 21, 2736-2742 (2002).

M. Niehues, G. Erker, G. Kehr, P. Schwab, R. Fröhlich, O. Blacque, H. Berke. Synthesis and Structural Features of Arduengo Carbene Complexes of Group 4 Metalocene Cations. Organometallics, 21, 2905-2911 (2002).

H. V. Huynh, C. Schulze-Isfort, W. W. Seidel, T. Lügger, R. Fröhlich, O. Kataeva, F. E. Hahn. Dinuclear Complexes with Bis(benzenedithiolate) Ligands. Chem. Eur. J., 8, 1327-1335 (2002).

G. Altenhoff, S. Bredeau, G. Erker, G. Kehr, O. Kataeva, R. Fröhlich. Structural Features of Me₂Si-Bridged Cp/Phosphido Group 4 Matal Complexes, “CpSiP“ Constrained-Geometry Ziegler-Natta Catalyst Precursors. Organometallics, 21, 4084-4089 (2002).

H. V. Huynh, W. W. Seidel, T. Lügger, R. Fröhlich, B. Wibbeling, F. E. Hahn. ortho-Lithiation of Benzene-1,2-dithiol: A Methodology for ortho-Functionalization of Benzene-1,2-dithiol. Z. Naturforsch., 57b, 1401-1408 (2002).

R. Aumann, X. Fu, C. Holst, R. Fröhlich. Á-Methylenation and á-Alkenylation of á,â-Unsaturated Amides by Means of Carbene Tungsten Complexes: A Novel Baylis-Hillman Type Reaction. Organometallics, 21, 4356-4368 (2002).

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).