SYNTHESIS OF GROUP 4 METAL RAC-(EBI)M(NR2)2 COMPLEXES BY AMINE ELIMINATION. SCOPE AND LIMITATIONS

The synthesis of (EBI)M(NR2)2 (M = Ti, Zr, Hf; EBI = ethylene-1,2-bis(1-indenyl)) complexes by amine elimination reactions of (EBI)H2 (1,2-bis(3-indenyl)ethane) and M(NR2)4 complexes has been investigated. The reaction of (EBI)H2 and Zr(NEt2)4 in toluene at 100 °C (15 h) yields the mono(indenyl) complex (η5-C9H6CH2CH2C9H7)Zr(NEt2)3 via a single amine elimination. Under more forcing conditions (1,2-dichlorobenzene, 180 °C, 21 h) this reaction yields the metallocene dichloride derivative (EBI)ZrCl2 (80% NMR, rac/meso ratio = 1.7/1). The reaction of (EBI)H2 with Zr(NMe2)2(NiPr2)2 in m-xylene at 140 °C (16 h) affords the sterically least hindered ansa-metallocene product, (EBI)Zr(NMe2)2 (70% NMR, rac/meso ratio = 2/1), via NiPr2H elimination. The reaction of (EBI)H2 with the pyrrolidide complex Zr(NC4H8)4 in m-xylene at 140 °C (7 h) yields (EBI)Zr(NC4H8)2 (95%, rac/meso ratio = 6/1) and pure rac-(EBI)Zr(NC4H8)2 in 42% isolated yield. (EBI)H2 reacts with the sterically open titanium azetidide complex Ti(NC3H6)...

[1]  J. L. Petersen,et al.  Synthesis, Structure, and Reactivity of rac-Me2Si(indenyl)2Zr(NMe2)2 , 1996 .

[2]  G. Diamond,et al.  Synthesis of Me 2 Si-Bridged ansa -Zirconocenes by Amine Elimination , 1996 .

[3]  I. Kim,et al.  Propylene polymerization with ansa-metallocene amide complexes , 1996 .

[4]  J. Y. Corey,et al.  The X-ray crystal structures of the ansa-metallocenes, Me2C(C5H4)2MCl2 (M = Ti, Zr and Hf) , 1995 .

[5]  Ann Thayer,et al.  Metallocene Catalysts Initiate New Era In Polymer Synthesis , 1995 .

[6]  J. Verkade,et al.  Synthesis and Characterization of a Novel Azatitanatrane , 1995 .

[7]  M. Nantz,et al.  Synthesis of ansa-titanocenes from 1,2-bis(2-indenyl) ethane and structural comparisons in the catalytic epoxidation of unfunctionalized alkenes , 1995 .

[8]  N. Taylor,et al.  Addition of a sterically hindered, chiral crotyl ansa-titanocene complex to aldehydes , 1995 .

[9]  W. Kaminsky,et al.  Crystal structure and propene polymerization characteristics of bridged zirconocene catalysts , 1995 .

[10]  J. Bercaw,et al.  C2-symmetric ansa metallocenes of titanium and zirconium with a ligand system that yields pure rac isomer: preparation and crystal structures of rac-η5-C5H22-SiMe34-CMe3)2SiMe3MCl2(M = Ti or Zr) , 1995 .

[11]  R. Rogers,et al.  Tetraaza Macrocycles as Ancillary Ligands in Early Metal Alkyl Chemistry. Synthesis and Characterization of Out-of-Plane (Me4taen)ZrX2 (X = alkyl, benzyl, NMe2, Cl) and (Me4taen)ZrX2(NHMe2) (X = Cl, CCPh) Complexes , 1995 .

[12]  David Fischer,et al.  Stereospecific Olefin Polymerization with Chiral Metallocene Catalysts , 1995 .

[13]  A. Sironi,et al.  Crystal Structures and Solution Conformations of the Meso and Racemic Isomers of (Ethylenebis(1-indenyl))zirconium Dichloride , 1995 .

[14]  S. Collins,et al.  ASYMMETRIC INDUCTION IN THE DIELS-ALDER REACTION CATALYZED BY CHIRAL METALLOCENE TRIFLATE COMPLEXES : DRAMATIC EFFECT OF SOLVENT POLARITY , 1995 .

[15]  B. Bosnich,et al.  Homogeneous catalysis: use of chiral titanocene complexes for asymmetric catalytic Diels–Alder reactions , 1995 .

[16]  G. Diamond,et al.  EFFICIENT SYNTHESIS OF RAC-(ETHYLENEBIS(INDENYL)ZRX2 COMPLEXES VIA AMINE ELIMINATION , 1995 .

[17]  S. Buchwald,et al.  Enantioselective hydrosilylation of ketones with a chiral titanocene catalyst , 1994 .

[18]  S. Buchwald,et al.  CATALYTIC ASYMMETRIC HYDROGENATION OF IMINES WITH A CHIRAL TITANOCENE CATALYST : KINETIC AND MECHANISTIC INVESTIGATIONS , 1994 .

[19]  N. Coville,et al.  Homogeneous group 4 metallocene ziegler-natta catalysts: The influence of cyclopentadienyl-ring substituents , 1994 .

[20]  S. Buchwald,et al.  CATALYTIC ASYMMETRIC HYDROGENATION OF IMINES WITH A CHIRAL TITANOCENE CATALYST : SCOPE AND LIMITATIONS , 1994 .

[21]  S. Buchwald,et al.  ASYMMETRIC HYDROGENATION OF ENAMINES WITH A CHIRAL TITANOCENE CATALYST , 1994 .

[22]  T. Ramsey,et al.  Catalytic Asymmetric Hydrosilation of Aryl Alkyl Ketones with C2-Symmetric Chiral Metallocene Complexes , 1994 .

[23]  Avelino Martín,et al.  Dialkylamido derivatives of [(η5-C5Me5)TiCl3], [(η5-C5Me5) TiCl22(μ-O)] and [(η5-C5Me5)TiCl3(μ-O)3]: X-ray crystal structure of [(η5-C5Me5)Ti(NMe2)3] , 1994 .

[24]  B. Bachmann,et al.  The Influence of Aromatic Substituents on the Polymerization Behavior of Bridged Zirconocene Catalysts , 1994 .

[25]  R. Muelhaupt,et al.  ansa-Zirconocene Polymerization Catalysts with Anelated Ring Ligands - Effects on Catalytic Activity and Polymer Chain Length , 1994 .

[26]  S. Buchwald,et al.  Asymmetric hydrogenation of unfunctionalized trisubstituted olefins with a chiral titanocene catalyst , 1993 .

[27]  M. Bochmann.  Kationische Alkylkomplexe für die Olefinpolymerisation , 1993 .

[28]  T. Ramsey,et al.  Asymmetric synthesis of a sterically rigid binaphthyl-bridged chiral metallocene : asymmetric catalytic epoxidation of unfunctionalized alkenes , 1993 .

[29]  P. Fanwick,et al.  Aryl imido complexes of the group 4 metals: Structural aspects and mechanistic study of formation , 1993 .

[30]  B. Bachmann,et al.  High Molecular Weight Polypropylene through Specifically DesigneZirconocene Catalysts , 1992 .

[31]  R. L. Halterman.  Synthesis and Applications of Chiral Cyclopentadienylmetal Complexes , 1992 .

[32]  W. Kaminsky,et al.  Standardized polymerizations of ethylene and propene with bridged and unbridged metallocene derivatives: A comparison† , 1992 .

[33]  Zhuoliang Chen,et al.  Enantioselective catalytic isomerization of an unfunctionalized achiral alkene , 1992 .

[34]  S. Colletti,et al.  Asymmetric epoxidation of unfunctionalized alkenes using the new C2-symmetrical 1,1′-binaphthyl-2,2′-dimethylene-bridged ansa-Bis(1-indenyl)titanium dichloride catalyst , 1992 .

[35]  J. Bartmess,et al.  Intrinsic (gas-phase) basicity of some anionic bases commonly used in condensed-phase synthesis , 1992 .

[36]  K. Rypdal,et al.  Molecular structures of titanium(IV) and vanadium(IV) amides and alkoxides , 1992 .

[37]  T. Marks.  Surface-bound metal hydrocarbyls. Organometallic connections between heterogeneous and homogeneous catalysis , 1992 .

[38]  F. Fronczek,et al.  Stereoselectivity in the synthesis of tetramethylethano-bridged 3,3'-di-tert-butyltitanocene dichloride , 1991 .

[39]  N. Taylor,et al.  Synthesis of pure racemic isomers of ansa-titanocene dichlorides: conformational preferences are determined by substitution patterns on the cyclopentadienyl rings , 1991 .

[40]  S. Buchwald,et al.  Syntheses of [ethylene-1,2-bis(.eta.5-4,5,6,7-tetrahydro-1-indenyl)]zirconium and -hafnium hydride complexes. Improved syntheses of the corresponding dichlorides , 1991 .

[41]  R. F. Jordan.  Chemistry of Cationic Dicyclopentadienyl Group 4 Metal-Alky I Complexes , 1991 .

[42]  N. Taylor,et al.  General synthetic routes to chiral, ethylene-bridged ansa-titanocene dichlorides , 1990 .

[43]  A. Winter,et al.  Stereorigid metallocenes : correlations between structure and behaviour in homopolymerizations of propylene , 1990 .

[44]  K. G. Caulton,et al.  Synthesis of Zr-Re-containing polyhydrides by amine elimination , 1989 .

[45]  H. Yamazaki,et al.  Excellent Stereoregular Isotactic Polymerizations of Propylene with C2-Symmetric Silylene-Bridged Metallocene Catalysts , 1989 .

[46]  S. Collins,et al.  Additions of chiral allyltitanocenes to aldehydes: diastereoselective synthesis of homoallylic alcohols with a recyclable chiral transition metal reagent , 1989 .

[47]  H. Brintzinger,et al.  ansa-Metallocene derivatives: XVII. Racemic and meso diastereomers of group IV metallocene derivatives with symmetrically substituted, dimethylsilanediyl-bridged ligand frameworks. Crystal structure of R,S-Me2Si(3-t-Bu-5-MeC5H2)2ZrCl2 , 1989 .

[48]  A. J. Nielson.  Alkylimido complexes of titanium(IV) , 1988 .

[49]  B. Santarsiero,et al.  Synthesis and molecular structure of (η5-C5Me5)2Hf(H)(NHMe). Structural evidence for nitrogen-to-hafnium π-donation , 1988 .

[50]  C. J. Holwill,et al.  Gas-phase electron diffraction study of tetrakis(dimethylamido)zirconium(IV), Zr(NMe2)4 , 1988 .

[51]  N. Taylor,et al.  X-Ray structures of ethylenebis(tetrahydroindenyl)-titanium and -zirconium dichlorides: a revision , 1988 .

[52]  M. Chisholm,et al.  Tetrakisdimethylamidozirconium and its dimethylamido lithium adduct: Structures of [zr(nme2)4]2 and zr(nme2)6li2(thf)2 , 1988 .

[53]  E. Baerends,et al.  A theoretical study of metal—ligand bond strengths (ML: L = OH, OCH3, SH, NH2, PH2, CH3, SiH3, CN and H) in the early transition metal systems Cl3ML (M = Ti, Zr and Hf) and late transition metal systems LCo(CO)4 , 1988 .

[54]  T. Marks,et al.  Organometallic thermochemistry. Metal hydrocarbyl, hydride, halide, carbonyl, amide, and alkoxide bond enthalpy relationships and their implications in pentamethylcyclopentadienyl and cyclopentadienyl complexes of zirconium and hafnium , 1988 .

[55]  J. Atwood,et al.  Propylene Polymerizations with Group 4 Metallocene/Alumoxane Systems , 1988 .

[56]  H. Brintzinger.  Synthesis and Characterisation of Chiral Metallocene Cocatalysts for Stereospecific α-Olefin Polymerisations , 1988 .

[57]  J. Atwood,et al.  Crystal structures and stereospecific propylene polymerizations with chiral hafnium metallocene catalysts , 1987 .

[58]  W. Kaminsky,et al.  Polymerization of Propene and Butene with a Chiral Zirconocene and Methylalumoxane as Cocatalyst , 1985 .

[59]  J. Ewen.  Mechanisms of stereochemical control in propylene polymerizations with soluble Group 4B metallocene/methylalumoxane catalysts , 1984 .

[60]  W. A. Nugent,et al.  Catalytic C-H activation in early transition-metal dialkylamides and alkoxides , 1983 .

[61]  L. Zsolnai,et al.  ansa-Metallocene Derivatives : IV. Synthesis and molecular structures of chiral ansa-titanocene derivatives with bridged tetrahydroindenyl ligands , 1982 .

[62]  G. Huttner,et al.  ansa-Metallocene derivatives , 1979 .

[63]  R. D. Shannon.  Revised effective ionic radii and systematic studies of interatomic distances in halides and chalcogenides , 1976 .

[64]  R. Hoffmann,et al.  Structure and chemistry of bis(cyclopentadienyl)-MLn complexes , 1976 .

[65]  A. Clearfield,et al.  Structural Studies of (π-C5H5)2MX2 Complexes and their Derivatives. The Structure of Bis(π-cyclopentadienyl)titanium Dichloride , 1975 .

[66]  J. Pedley,et al.  Standard heats of formation and M–C bond energy terms for some homoleptic transition metal alkyls MRn , 1975 .

[67]  D. C. Bradley.  Metal alkoxides and dialkylamides , 1972 .

[68]  M. Lappert,et al.  Amido-derivatives of metals and metalloids. Part VI. Reactions of titanium(IV), zirconium(IV), and hafnium(IV) amides with protic compounds , 1968 .

[69]  D. C. Bradley,et al.  765. Metallo-organic compounds containing metal–nitrogen bonds. Part I. Some dialkylamino-derivatives of titanium and zirconium , 1960 .