Triple C–H Bond Activation of a Nickel-Bound Methyl Group: Synthesis and X-Ray Structure of a Carbide Cluster (NiCp)6(μ6-C)

2012 ◽  
Vol 51 (15) ◽  
pp. 8292-8297 ◽  
Author(s):  
Włodzimierz Buchowicz ◽  
Beata Herbaczyńska ◽  
Lucjan B. Jerzykiewicz ◽  
Tadeusz Lis ◽  
Stanisław Pasynkiewicz ◽  
...  
Keyword(s):  
Bond Activation ◽  
Methyl Group ◽  
X Ray ◽  
Carbide Cluster

The Pyrolytic Rearrangement of 1-Alkynoyl-3-methylpyrazoles: Synthesis of Pyrazolo[1,5-a]pyridin-5-ols and Related Compounds

1994 ◽  
Vol 47 (6) ◽  
pp. 991 ◽  
Author(s):  
RFC Brown ◽  
FW Eastwood ◽  
GD Fallon ◽  
SC Lee ◽  
RP Mcgeary
Keyword(s):  
Carbon Chain ◽  
Ring Structure ◽  
High Yield ◽  
Methyl Group ◽  
X Ray ◽  
X Ray Crystallography ◽  
Flash Vacuum Pyrolysis ◽  
Vacuum Pyrolysis ◽  
Fused Ring ◽  
Related Compounds

Flash vacuum pyrolysis of 1-(alkyn-2′-oyl)-3-methylpyrazoles at 650°/0.03 mm forms pyrazolo[1,5-a]pyridin-5-ols, often in high yield, which may bear substituents at C2, C3 or C7. In the absence of a 3-methyl group in the precursor, N-ethynylpyrazoles are formed in low yield. The formation of both types of product is interpreted as involving 3-(N-pyrazolyl)propadienones formed by N1 → N2 migration of the N-alkynoyl group with inversion of the three-carbon chain. The fused-ring structure of 2-methylpyrazolo[1,5-a]pyridin-5-ol (25) was established by X-ray crystallography of the O-benzoyl derivative (27).

CF bond activation in polyfluorobenzothiolate compounds of Os(III). X-ray structures of [-2))(SC6F5)2(PMe2Ph)2], [Os(SC6F5)2(o-S2C6F4)(PMe2Ph)] and [Os(C6F5)2(o-S2C6F4)(PMe2Ph)2]

2000 ◽  
Vol 599 (2) ◽  
pp. 170-177 ◽  
Author(s):  
Maribel Arroyo ◽  
Sylvain Bernès ◽  
Jose Luis Brianso ◽  
Estela Mayoral ◽  
Raymond L. Richards ◽  
...  
Keyword(s):  
Bond Activation ◽  
X Ray

scholarly journals Reactions of Titanocene- and Zirconocene-Bis(trimethylsilyl)acetylene Complexes with Selected Heterocyclic and Aromatic NH and OH Acid Compounds

2007 ◽  
Vol 72 (4) ◽  
pp. 475-491 ◽  
Author(s):  
Perdita Arndt ◽  
Vladimir V. Burlakov ◽  
Ulrike Jäger-Fiedler ◽  
Marcus Klahn ◽  
Anke Spannenberg ◽  
...  
Keyword(s):  
Bond Activation ◽  
Reaction Pathway ◽  
Reaction Products ◽  
X Ray ◽  
X Ray Crystallography

The titanocene complexes Cp'2Ti(η2-Me3SiC2SiMe3) (Cp' = Cp (1), Cp* (2)) react with pyrrole under the formation of the titanium(III) mono-N-pyrrolides Cp'2Ti(NC4H4) (Cp' = Cp (6), Cp* (7)); whereas the corresponding zirconocene system Cp2Zr(η2-Me3SiC2SiMe3)(thf) (3) forms in a different reaction pathway first the Cp2Zr(NC4H4)[C(SiMe3)=CH(SiMe3)] (8) and then the zirconium(IV) bis-N-pyrrolide Cp2Zr(NC4H4)2 (11). With Cp*2Zr(η2-Me3SiC2SiMe3) (4) and pyrrole, the zirconium(IV) mono-N-pyrrolide with an agostic alkenyl group Cp*2Zr(NC4H4)[C(SiMe3)=CH(SiMe3)] (9) was obtained. In the reaction of the ethylenebistetrahydroindenyl (ebthi) complex rac-(ebthi)Zr(η2-Me3SiC2SiMe3) (5) with 2,3,5,6-tetrafluoroaniline under N-H bond activation, a complex with an agostic alkenyl group rac-(ebthi)Zr(NH-C6HF4)[C(SiMe3)=CH(SiMe3)] (10) was formed. Compound 10 reacts with additional 2,3,5,6-tetrafluoroaniline to give the bisanilide rac-(ebthi)Zr(NH-C6HF4)2 (12) which was obtained directly from 5 with two equivalents of 2,3,5,6-tetrafluoroaniline. In reactions of complex 5 with unsubstituted aniline to rac-(ebthi)Zr(NH-C6H5)2 (13) and with pentafluorophenol to bisphenolate rac-(ebthi)Zr(O-C6F5)2 (14), no intermediates could be isolated. The new reaction products 6, 9, 10, 12, 13 and 14 were investigated by X-ray crystallography.

Electrophilic Additions of Mercury and Gold Species to the Anion Carbide Cluster [Fe5C(CO)14]2-. X-ray Crystal Structures of (NEt4)[Fe5C(CO)14{μ-HgW(CO)3Cp}] and (NEt4)2[μ4-Hg{Fe5C(CO)14}2]

1998 ◽  
Vol 17 (19) ◽  
pp. 4127-4135 ◽  
Author(s):  
Roser Reina ◽  
Olga Riba ◽  
Oriol Rossell ◽  
Miquel Seco ◽  
Pilar Gómez-Sal ◽  
...  
Keyword(s):  
Crystal Structures ◽  
X Ray ◽  
Carbide Cluster ◽  
Electrophilic Additions

The Structure of Polyisoprenes. II. The Structure of β-Gutta-Percha

1945 ◽  
Vol 18 (2) ◽  
pp. 280-283
Author(s):  
G. A. Jeffrey
Keyword(s):  
Molecular Structure ◽  
Double Bond ◽  
Diffraction Data ◽  
X Ray Diffraction ◽  
Interatomic Distances ◽  
Methyl Group ◽  
X Ray ◽  
Gutta Percha ◽  
Qualitative Estimate

Abstract The x-ray diffraction data at present available from β-gutta-percha are shown to be insufficient to distinguish fine details of molecular structure. Since a qualitative estimate of the intensities on the fibre diagram can be adequately satisfied by a model having normal interatomic distances and valency angles, no evidence exists for the improbable distortion of the methyl group out of the plane of the double bond previously ascribed to the molecule.

Double C−H Bond Activation of an NHC N-Methyl Group on Triruthenium and Triosmium Carbonyl Clusters: A DFT Mechanistic Study

2008 ◽  
Vol 27 (18) ◽  
pp. 4697-4702 ◽  
Author(s):  
Javier A. Cabeza ◽  
Enrique Pérez-Carreño
Keyword(s):  
Bond Activation ◽  
Mechanistic Study ◽  
Carbonyl Clusters ◽  
Methyl Group ◽  
Triosmium Carbonyl Clusters

scholarly journals Valence‐to‐Core X‐ray Emission Spectroscopy as a Probe of O−O Bond Activation in Cu 2 O 2 Complexes

2019 ◽  
Vol 58 (27) ◽  
pp. 9114-9119 ◽  
Author(s):  
George E. Cutsail ◽  
Nicole L. Gagnon ◽  
Andrew D. Spaeth ◽  
William B. Tolman ◽  
Serena DeBeer
Keyword(s):  
Emission Spectroscopy ◽  
Bond Activation ◽  
X Ray

The Conformation of the Side Chain of 21-Alkylpregnanes

2003 ◽  
Vol 2003 (9) ◽  
pp. 556-558 ◽  
Author(s):  
James R. Hanson ◽  
Peter B. Hitchcock ◽  
Jorge A.R. Salvador
Keyword(s):  
Crystal Structures ◽  
Side Chain ◽  
Methyl Group ◽  
X Ray

The X-ray crystal structures of some 21-alkylpregnanes have been determined and the effects of a 16α,17α-epoxide and 21-methyl group on the conformation of the side chain are discussed.

The crystal structure of 5-O-Acetyl-1,2 : 3,4-di-O-isopropylidene-α-D-glucoseptanose, C14H22O7, by use of X-ray and neutrondiffraction data

1983 ◽  
Vol 36 (11) ◽  
pp. 2269 ◽  
Author(s):  
RA Wood ◽  
VJ James ◽  
AD Rae ◽  
JD Stevens ◽  
FH Moore
Keyword(s):  
Crystal Structure ◽  
Neutron Diffraction ◽  
Diffraction Analysis ◽  
Chair Conformation ◽  
Asymmetric Unit ◽  
Methyl Group ◽  
Neutron Diffraction Analysis ◽  
X Ray ◽  
Acetate Methyl ◽  
Independent Molecules

The crystal structure of 5-O-acetyl-1,2:3,4-di-O-isopropylidene-α-D-glucoseptanose [P212121, Z 8, a 14.329(5), b 22.075(5), c 10.012(5) �] has been determined by X-ray and neutron diffraction analyses. For the neutron diffraction analysis, the acetate group and the trans-O-isopropylidene group were deuterated. Constrained refinement was used in the neutron diffraction analysis to counter over parameterization in the block-diagonal least-squares refinement. Final unweighted R-values were 0.038 [X-ray for 3070 reflections with [Fo > 2.58σ (Fo)] and 0.061 [neutron for 1118 reflections with Fo > 4σ ([Fo)]The neutron refinement revealed a disordering of the acetate methyl group in each of the two independent molecules in the asymmetric unit. The septanose ring in each molecule adopted the same twist-chair conformation but the dioxolan rings assumed different twist and envelope conformations.

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