Open-Cage Fullerene Derivatives Having 11-, 12-, and 13-Membered-Ring Orifices:  Chemical Transformations of the Organic Addends on the Rim of the Orifice

2007 ◽  
Vol 72 (17) ◽  
pp. 6526-6533 ◽  
Author(s):  
Manolis M. Roubelakis ◽  
Georgios C. Vougioukalakis ◽  
Michael Orfanopoulos
Keyword(s):  
Membered Ring ◽  
Chemical Transformations ◽  
Fullerene Derivatives

Untersuchungen zur Chemie von Isoindolen und Isoindoleninen, XXXX. 3-Hydroximino-1-alkyl(aryl)-isoindoline und 3-Hydroxylamino-1-alkyl(aryl)-1Hisoindole - Modellverbindungen für Struktur- und Reaktivitätsuntersuchungen - / Studies on the Chemistry of Isoindoles and Isoindolenines, XXXX. 3-Hydroximino-1-alkyl(aryl)-isoindolines and 3-Hydroxylamino-1-alkyl(aryl)-1Hisoindoles - Model Compounds for Investigations of Structure and Reactivity -

1996 ◽  
Vol 51 (12) ◽  
pp. 1791-1810 ◽  
Author(s):  
Andrea Clemens ◽  
Richard P. Kreher ◽  
Johannes Preut
Keyword(s):  
Crystal Structure ◽  
Structure Determination ◽  
Membered Ring ◽  
Crystal Structure Determination ◽  
Chemical Transformations ◽  
Model Compounds ◽  
Alkyl Aryl ◽  
Spectroscopic Investigations

3-Hydroximino-isoindolines and 3-hydroxylamino-1 H-isoindoles with substituents at the five membered ring have been prepared by condensation of substituted 3-alkoxy-1 H-isoindoles with hydroxylamine and O-/N -substituted hydroxylamines. Constitution and configuration of semi-cyclic amidoximes were derived from spectroscopic investigations and deduced on the basis of orientating chemical transformations. These results have been established by a crystal structure determination of a representative 3-hydroximino-isoindoline.

Open-Cage Fullerene Derivatives with 15-Membered-Ring Orifices

2004 ◽  
Vol 69 (13) ◽  
pp. 4524-4526 ◽  
Author(s):  
Georgios C. Vougioukalakis ◽  
Kosmas Prassides ◽  
Josep M. Campanera ◽  
Malcolm I. Heggie ◽  
Michael Orfanopoulos
Keyword(s):  
Membered Ring ◽  
Fullerene Derivatives

scholarly journals Organocatalysis: A Tool of Choice for the Enantioselective Nucleophilic Dearomatization of Electron-Deficient Six-Membered Ring Azaarenium Salts

Catalysts ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1249
Author(s):  
Claire Segovia ◽  
Pierre-Antoine Nocquet ◽  
Vincent Levacher ◽  
Jean-François Brière ◽  
Sylvain Oudeyer
Keyword(s):  
Asymmetric Catalysis ◽  
Complex Compounds ◽  
Membered Ring ◽  
Low Energy ◽  
The Other ◽  
Great Success ◽  
Chemical Transformations ◽  
3D Scaffolds ◽  
High Level ◽  
Powerful Strategy

Nucleophilic dearomatization of azaarenium salts is a powerful strategy to access 3D scaffolds of interest from easily accessible planar aromatic azaarene compounds. Moreover, this approach yields complex dihydroazaarenes by allowing the functionalization of the scaffold simultaneously to the dearomatization step. On the other side, organocatalysis is nowadays recognized as one of the pillars of the asymmetric catalysis field of research and is well-known to afford a high level of enantioselectivity for a myriad of transformations thanks to well-organized transition states resulting from low-energy interactions (electrostatic and/or H-bonding interactions…). Consequently, in the last fifteen years, organocatalysis has met great success in nucleophilic dearomatization of azaarenium salts. This review summarizes the work achieved up to date in the field of organocatalyzed nucleophilic dearomatization of azaarenium salts (mainly pyridinium, quinolinium, quinolinium and acridinium salts). A classification by organocatalytic mode of activation will be disclosed by shedding light on their related advantages and drawbacks. The versatility of the dearomatization approach will also be demonstrated by discussing several chemical transformations of the resulting dihydroazaarenes towards the synthesis of structurally complex compounds.

Efficient Synthesis of Open-Cage Fullerene Derivatives Having 16-Membered-Ring Orifices

2007 ◽  
Vol 72 (18) ◽  
pp. 7042-7045 ◽  
Author(s):  
Manolis M. Roubelakis ◽  
Yasujiro Murata ◽  
Koichi Komatsu ◽  
Michael Orfanopoulos
Keyword(s):  
Membered Ring ◽  
Efficient Synthesis ◽  
Fullerene Derivatives

FULLERENE DERIVATIVES: STRUCTURES AND STABILITIES OF C60O AND C70O

1992 ◽  
Vol 06 (23n24) ◽  
pp. 3821-3831 ◽  
Author(s):  
KRISHNAN RAGHAVACHARI
Keyword(s):  
Oxygen Atom ◽  
Infrared Spectra ◽  
Ground State ◽  
Membered Ring ◽  
Low Energy ◽  
Fullerene Derivatives ◽  
Hartree Fock ◽  
Semi Empirical ◽  
Very High ◽  
C Nmr

Semi-empirical (MNDO) and ab-initio Hartree-Fock (3–21G) calculations on the structures and stabilities of C 60 O and C 70 O are reported. Two low energy isomers of C 60 O , formed by an oxygen atom bridging the two different C–C bonds in C 60, have been found. The first isomer has an epoxide structure with a bridging oxygen across the bond between two fused six-membered rings in C 60 (bridging C–C≈1.6 Å). Its 13 C NMR and infrared spectra are consistent with those seen for the experimentally isolated form of C 60 O . However, the second isomer containing a bridging oxygen across the bond between a five- and a six-membered ring is slightly more stable and appears to be the ground state of C 60 O . The bridging C–C bond opens out to a distance of ≈2.1 Å in this isomer. Endohedral isomers of C 60 O are calculated to be very high in energy. For C 70 O , we have characterized eight isomers formed by an oxygen atom bridging each of the eight distinct C–C bonds in C 70. The ground state isomer corresponds to oxygen bridging across an equatorial C–C bond in C 70 which opens out to a distance of ≈2.2 Å. This structure is different from the bridged paracyclene-like isomer proposed previously for C 70 O . Comparison is made between C 60 O and C 70 O .

Photoisomerization of Bicyclo[3.1.1]heptan-2-ones in Methanol: Chemical Transformations of 'Verbanones'

1975 ◽  
Vol 53 (11) ◽  
pp. 1657-1669 ◽  
Author(s):  
Alex G. Fallis
Keyword(s):  
Carbonyl Group ◽  
Alkyl Radical ◽  
Membered Ring ◽  
Chemical Transformations ◽  
Photochemical Behavior ◽  
Unsaturated Aldehydes ◽  
Cyclopropyl Ketones

The products (predominantly unsaturated aldehydes) from photolysis in methanol of a series of 6,6-dimethylbicyclo[3.1.1]heptan-2-ones are reported. These results are rationalized on the basis of stereochemical interactions and the apparent preference for cleavage to occur adjacent to the less highly substituted α-carbon but more stable alkyl radical. It is concluded that the photochemical behavior of α-cyclobutyl ketones displays a closer parallel to the α-cyclopropyl ketones than previously recognized and that cleavage will occur preferentially on the side of the carbonyl group remote from the four-membered ring whenever possible. The synthetic steps involved in the preparation of the ketones from 'pinene' precursors are described.

scholarly journals Efficient Synthesis of Open-Cage Fullerene Derivatives Having 16-Membered-Ring Orifices.

ChemInform ◽  
2007 ◽  
Vol 38 (49) ◽  
Author(s):  
Manolis M. Roubelakis ◽  
Yasujiro Murata ◽  
Koichi Komatsu ◽  
Michael Orfanopoulos
Keyword(s):  
Membered Ring ◽  
Efficient Synthesis ◽  
Fullerene Derivatives
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