Wolfgang Schütt

Darstellung und struktur von 1-metalla-2,3,4-triazolen des molybdäns und wolframs

The reaction of cyclopentadienyl substituted carbyne complexes of molybdenum and tungsten C5H5(CO)2-n(PMe3)n MCR (M  Mo, W; R  C6H5, C6H4CH3, CH3, n = 0, 1) (la–3c) with azides N3R′ (R′ CO2CH3, CH2CO2CH3) results in a [3 + 2]-cycloaddition to the electron-rich metal carbon triple bond, producing neutral 1-metalla-2,3,4-triazole complexes C5H5(CO)2-n(PMe3)nMC(R)NNNR′(M  MO, W; R  C6H5, C6H4CH3, CH3, n = 0, 1) (4a–7c) in high yields.The new compounds were identified by X-ray structure analysis (5b), elemental analyses, NMR, IR and mass spectra.

Kationische η2-Thiocarbenkomplexe von Molybdän und Wolfram

Abstract Cyclopentadienyl and hydrotrispyrazolylborato substituted carbyne complexes of molybdenum and tungsten react with dimethyl (alkyl/arylthio)sulfonium tetrafluoroborate to yield cationic η 2 thiocarbene complexes.

Cycloaddition von Azidoameisensäuremethylester an die Metall-Kohlenstoff-Doppelbindung in [CP(CO)PMe3W=icr;C(Ph)SMe]+

The cationic thiocarbene complex [Cp(CO)PMe3W=icr;C(Ph)SMe]-[BF4] adds the azide N3COOMe to the electron-rich metal carbon double bond to yield the corresponding bicyclic system.

Reversible acyl-keten-umwandlung

Abstract Carbonyl(bistrifluoracetato)(η 5 -cyclopentadienyl)(η 2 -methylbenzylacyl)tungsten ( 5 ) reacts with 1,8-diazabicyclo[5.4.0]undecen (DBU) under deprotonation to give the anionic ketenyl complex [η 5 -C 5 H 5 (CO)(CF 3 COO) 2 W(OCC(H)C 6 H 4 CH 3 ][DBUH] ( 3 ). Subsequent treatment of 3 with trifluoroacetic acid trimethyloxonium tetrafluoroborate or methanol affords the original acyl complex ( 5 ), its methyl substituted derivative ( 6 ) or an ester ( 7 ).

Darstellung und Röntgenstrukturuntersuchung von [1-Carbonyl-1-(η5-cyclopentadienyl)-2,3-dimethyl-1-trimethylphosphin-3-trimethylphosphoranyliden-1-wolframa-2-thiacyclopropan]-tetrafluoroborat

Abstract Dicarbonyl(η5-cyclopentadienyl)[η2-(methylthio)methylcarbene] tungsten tetrafluoroborate reacts with an excess of trimethylphosphine under carbonyl substitution and addition of trimethylphosphine at the carbene carbon to yield a ‘wolframa-thiacyclopropane’ complex with a trimethylphosphoranylidene unit. Synthesis, spectroscopic investigation and the X-ray structure are reported.

Zur addition des thiomethyl-kations an die Wolfram-Kohlenstoff-Doppelbindung in [Cp(CO)(PMe3)WC(Tol)PR2][PF6]

Abstract Carbonyl(η 5 -cyclopentadienyl)(trimethylphosphine)[η 2 -(dimethylphenylphosphino-4-methylphenylcarbene]tungsten hexafluorophosphate reacts with dimethyl(methylthio)sulfonium tetrafluoroborate to yield the dicationic complexes tungstaphosphathiabicyclo[1.1.0]butane.

Darstellung und Reaktionen von Trimethylphosphin-sbustituierten η2-Triocarbenkomplexes des Wolframs

Abstract Trimethylphosphine substituted η2-thiocarbene complexes of tungsten [Cp(CO)(PMe3) WC(R)S Me]-[BF4 R  Ph, Tol) are formed either by reacting carbonyl(η5-cyclopentadienyl)(trimethylphosphine)arylcarbynetungsten with dimethyl(methylthio)sulfonium tetrafluoroborate or by treatment of dicarbonyl(η5-cyclopentadienyl) [η2-(methylthio)arylcarbene]tungsten tetrafluoroborate with PMe3. Subsequent addition of PMe3 at the carbene carbon atom provides the corresponding ylid complexes.

Umsetzung von 2,4-Dithio-1-wolframa-bicyclo[l.1.01-butan-bis-tetrafluoroborat-Komplexen mit Thioharnstoff

Abstract The reacting of dicationic 1-tungsta-2,4-dithiabicyclobutane complexes ( 1a,b ) with thiourea dealkylation gives monocationic, bicyclic complexes in high yields. Further attempts to eliminate the remaining second S-methyl substituent by use of stronger bases in order to obtain the corresponding dithiocarboxylato complexes failed so far.

Kationische, acyclische thiocarbenkomplexe des wolframs☆

Dicarbonyl(η5-cyclopentadienyl)(triethyl- or triphenylphosphine)(η1-methylthiovinyl)tungsten reacts with an equimolar amount of tetrafluoroboric acid to yield the corresponding cationic thiocarbene complex [Cp(CO)2(PR3)WC(Me)SMe][BF4] (R  Et, Ph).

Umwandlung von η2-Thiocarbenkomplexen des Molybdäns und Wolframs in Metalla-thia-cyclopropan-Systeme / Conversion of η2-Thiocarbene Complexes of Molybdenum and Tungsten to Metalla-thio-cyclopropane Systems

Cationic η2-thiocarbene complexes of molybdenum and tungsten [Cp(CO)2Me][ BF4] (M = Mo, W; R = Ph, Tol; L = CO, PMe3) react with the germylene Ge{N(tBu)CH2CH2N(tBu)}, the plumbylene Pb{N(SiMe3)2}2, or with sodium azide and sodium thiosulfate to give neutral metalla-thia-cyclopropane complexes Cp(CO)2-. Instead of the expected cycloaddition or substitution reactions the formal addition of thiomethanolat at the carbene carbon atom is observed. On treating the corresponding trimethylphosphine substituted η2-thiocarbene complex of molybdenum [Cp(CO)(PMe3)[BF4] with diethylamine or N,N,N′,N′-tetramethylguanidine a cationic molybda-thia-cyclopropane system is formed. The products have been characterized by 1H, 13C, 31P NMR, IR and mass spectra. The crystal structure of 5a has been determined; space group with a = 1340,4(2), b - 1097,7(1), c = 1101,8(5) pm and Z = 4.