Hypercoordinate β-carbon in Grubbs and Schrock olefin metathesis metallacycles

2015 ◽  
Vol 44 (40) ◽  
pp. 17660-17672 ◽  
Author(s):  
Premaja R. Remya ◽  
Cherumuttathu H. Suresh
Keyword(s):  
Electron Density ◽  
Olefin Metathesis ◽  
Bond Order ◽  
Structural Bond ◽  
Nmr Data ◽  
C Nmr

From the analysis of structural, bond order, electron density and 13C NMR data of a large variety of ruthenacyclobutanes and tungstenacyclobutanes, we show that the Cβ of the metallacycle is pentacoordinate.

Complexes of dithiobenzoic acids. III.1H and 13C nuclear magnetic reonance studies of a series of tetrakis(dithiobenzoato)molybdenum(IV) complexes

1980 ◽  
Vol 58 (22) ◽  
pp. 2314-2317 ◽  
Author(s):  
T. Roberie ◽  
N. S. Bhacca ◽  
D. Lankin ◽  
J. Selbin
Keyword(s):  
Charge Density ◽  
Electron Density ◽  
Tetraalkylammonium Salts ◽  
Nmr Data ◽  
C Nmr ◽  
Nuclear Magnetic

A series of dithiocarboxalato (X-dtb) complexes of molybdenum(IV), Mo(X-dtb)4, where the para substituent X = H, CH3, CH3O, F, C6H5, CHO, C6H5CO, or (n-C4H9)2N, the parent acids and tetraalkylammonium salts were studied by 1H and 13C nmr in order to monitor the expected charge density shifts as a function of the group X. Analysis of the 13C nmr data unexpectedly revealed an absence of delocalization of electron density either from molybdenum to ligand or from ligand to molybdenum.

Glucan isolated from leaves of Althaea officinalis L.

1983 ◽  
Vol 48 (7) ◽  
pp. 2082-2087 ◽  
Author(s):  
Alžbeta Kardošová ◽  
Jozef Rosík ◽  
Rudolf Toman ◽  
Peter Capek
Keyword(s):  
Medicinal Plant ◽  
Periodate Oxidation ◽  
Linear Structure ◽  
Water Soluble ◽  
Partial Hydrolysis ◽  
Methylation Analysis ◽  
Glycosidic Bonds ◽  
Nmr Data ◽  
Althaea Officinalis ◽  
C Nmr

A water-soluble low-molecular D-glucan was isolated from leaves of the medicinal plant marsh-mallow (Althaea officinalis L.). The results of methylation analysis, partial hydrolysis, periodate oxidation, and 13C NMR data indicated a virtually linear structure with α-(1→6) glycosidic bonds.

Synthesis and characteristics of ethylenediamine-N,N'-di-S-α-isovalerate and isomers of its cobalt(III) complexes

1982 ◽  
Vol 47 (1) ◽  
pp. 210-216 ◽  
Author(s):  
Milan Strašák ◽  
František Bachratý ◽  
Jaroslav Majer
Keyword(s):  
Amino Acids ◽  
Absolute Configuration ◽  
Electronic Absorption ◽  
Electronic Absorption Spectra ◽  
Chemical Parameters ◽  
Methyl Group ◽  
Nmr Data ◽  
Physico Chemical ◽  
Natural Amino Acids ◽  
C Nmr

The synthesis and physico-chemical parameters are described of a new complexone based on natural amino acids, viz. ethylenediamine-N,N'-di-S-α-isovalerate (SS-EDDIV). 1H- and 13C-NMR data revealed that the methyl group in the substance are not equivalent. The isomers of the cobalt(III) complex with the asymmetric tetradentate SS-EDDIV ligand were prepared and separated; their characteristics are given. The absolute configuration of two of the five theoretically feasible isomers was determined based on their electronic absorption spectra and circular dichroism data.

scholarly journals Structural Investigations of C-Nitrosobenzenes. Part 3.1 Solid-state and Solution 13C NMR Studies, and Crystal Structure of E-(4-CIC6H4NO)2

1999 ◽  
Vol 23 (3) ◽  
pp. 202-203
Author(s):  
Daniel A. Fletcher ◽  
Brian G. Gowenlock ◽  
Keith G. Orrell ◽  
David C. Apperley ◽  
Michael B. Hursthouse ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
13C Nmr ◽  
Nmr Studies ◽  
Structural Investigations ◽  
Nmr Data ◽  
C Nmr

Solid-state and solution 13C NMR data for the monomers and dimers of 3- and 4-substituted nitrosobenzenes, and the crystal structure of E-(4-CIC6H4NO)2 are reported.

1-Carba-arachno-pentaborane(10) Derivatives

1997 ◽  
Vol 62 (8) ◽  
pp. 1254-1262 ◽  
Author(s):  
Bernd Wrackmeyer ◽  
Hans-Jörg Schanz
Keyword(s):  
High Yield ◽  
Exchange Reactions ◽  
Nmr Data ◽  
Substituted 1 ◽  
C Nmr

The formation of organo substituted 1-carba-arachno-pentaborane(10) derivatives is shown to proceed in high yield via in situ generated 1,1,1-tris(diethylboryl)propane (2) from diethyl(propyn-1-yl)borane (1) by hydroboration with an excess of diethylborane (hydride bath). In the hydride bath, exchange reactions between 2 and other geminal bis(diethylboryl)alkanes take place until the carbaborane skeleton is formed. If tris(diethylboryl)methane is used under the same conditions, the corresponding 1-carba-arachno-pentaborane(10) derivatives 11 and 12 are formed in mixture with other unknown boranes or carboranes. 11B and 13C NMR data are presented to allow for straightforward identification of the 1-carba-arachno-pentaboranes(10).

scholarly journals Assignment of 1 H- and 13 C-NMR data for four helminthosporol analogs with the bicyclo[3.2.1]oct-6-ene framework

2018 ◽  
Vol 56 (11) ◽  
pp. 1130-1134
Author(s):  
Kenji Tomita ◽  
Sho Miyazaki ◽  
Kazuo Furihata ◽  
Masatoshi Nakajima ◽  
Tadao Asami
Keyword(s):  
Nmr Data ◽  
C Nmr

NMR-spektroskopische Untersuchungen an 1,1-Thiophendioxid und verwandten Verbindungen / NMR Spectroscopical Investigations of Thiophene 1,1-Dioxide and Related Compounds

1984 ◽  
Vol 39 (7) ◽  
pp. 915-920 ◽  
Author(s):  
Herbert Meier ◽  
Thomas Molz ◽  
Heinz Kolshorn
Keyword(s):  
Computer Simulation ◽  
Chemical Shifts ◽  
Coupling Constants ◽  
Multiple Resonance ◽  
Nmr Data ◽  
Cyclic Diene ◽  
Related Compounds ◽  
C Nmr

The 1H and 13C NMR data of thiophene 1,1-dioxide (3) and related compounds, especially of the precursor 2 and the consecutive product 5 are evaluated by computer simulation and multiple resonance. Chemical shifts and coupling constants reveal that 3 has the character of a cyclic diene. Diatropic or paratropic effects can be excluded.

Sur une nouvelle méthode de synthèse de δ-lactones cyclopenténiques

1986 ◽  
Vol 64 (4) ◽  
pp. 831-836 ◽  
Author(s):  
Jean Claude Caille ◽  
Michel Farnier ◽  
Roger Guilard ◽  
André Aubry ◽  
Claude Lecomte
Keyword(s):  
Mass Spectrometry ◽  
Carbon Atom ◽  
X Ray ◽  
Nmr Data ◽  
C Nmr

Synthesis of two cyclopentenic δ-lactones, 1,3,4,4a,5,6-hexahydrocyclopenta[c]pyran-1-one and its analogue possessing a cyclopentenyl group bonded to the carbon atom 4a is described, starting from the cyclopentanone or cyclopentylidene cyclopentanone. The remarkable reactivity of the tosylhydrazones allows transformation of these compounds into substituted cyclopentenes, which lead to δ-lactones by cyclization. The conditions of cyclization depend on the nature of the cyclopentanone. The structure of the two δ-lactones is established by 1H and 13C nmr data, mass spectrometry, and, in one case, by X-ray analysis.

scholarly journals Synthesis of Some Novel Fused Imidazo [2, 1-b] [1, 3] Thiazole and Imidazo [2, 1-b] Thiazolo [5, 4-d] Isoxazole Derivatives

2012 ◽  
Vol 9 (3) ◽  
pp. 1518-1525 ◽  
Author(s):  
Hamid Reza Jaberi ◽  
Hadi Noorizadeh
Keyword(s):  
Acetic Acid ◽  
Sodium Acetate ◽  
Carbon Disulphide ◽  
Thiazole Derivatives ◽  
H Nmr ◽  
Nmr Data ◽  
Elemental Analyses ◽  
New Compounds ◽  
Isoxazole Derivatives ◽  
C Nmr

In this work we describe the synthesis of some novel fused imidazo [2, 1-b] [1, 3] thiazole derivatives. The reaction of 1, 2-diaminoethane 1 with carbon disulphide in H2O/ETOH as solvent furnishes 4, 5-dihydro-1H-imidazol-2-thiol 2 under reflux condition. the reaction of 4,5-dihydro-1H-imidazol-2-thiol on treatment with ethylchloro acetate and aromatic aldehyde in presence of anhydrous sodium acetate and acetic acid as solvent to give (Z)-2-(arylidene)-5,6-dihydroimidazo [2,1-b] [1,3] thiazol-3(2H)-one 3a-j. Compounds 3a-j was condensed with hydroxylamine to give 3-(aryl)-2, 3, 6, 7-tetrahydroimidazo [2, 1-b] [1,3] thiazolo [5, 4-d] isoxazole 4a-j. The structures of the new compounds were established by elemental analyses, IR,1H NMR and13C NMR data.

Metallocenylborane, IV. Diborylverbindungen des Ferrocens und Cymantrens.

1976 ◽  
Vol 31 (8) ◽  
pp. 1028-1034 ◽  
Author(s):  
Werner Ruf ◽  
Thomas Renk ◽  
Walter Siebert
Keyword(s):  
Redox Reaction ◽  
Lewis Acidity ◽  
Lewis Bases ◽  
Nmr Data ◽  
Halogen Exchange ◽  
Donor Acceptor ◽  
C Nmr

Ferrocene reacts with BI3 and BBr3 to give 1,1′-bis(dihalogenboryl)ferrocenes; the cyclopentadienylring in cymantrene is twice borylated by BI3. By halogen exchange with AsF3 and AsCl3, by methylation with Sn(CH3)4, by cleavage of (C2H5)2O, by redox reaction with (CH3S)2 and by reaction with (C2H5)2NH the corresponding diborylferrocenes are obtained. The air-sensitive halogenborylferrocenes form donor-acceptor compounds with Lewis bases. 1H, 11B and 13C NMR data reflect increasing π-acceptor properties with increasing Lewis acidity of the boryl groups.

Sign in / Sign up

Export Citation Format

Share Document