scholarly journals Synthetic and Theoretical Studies of Novel Ring Closure and Ring Opening Reactions

ChemInform ◽  
2006 ◽  
Vol 37 (40) ◽  
Author(s):  
Jose Sepulveda-Arques ◽  
M. Eugenia Gonzalez-Rosende
Keyword(s):  
Ring Opening ◽  
Ring Closure ◽  
Theoretical Studies ◽  
Ring Opening Reactions

scholarly journals Synthetic and theoretical studies of novel ring closure and ring opening reactions

ARKIVOC ◽  
2005 ◽  
Vol 2006 (7) ◽  
pp. 5-19
Author(s):  
José Sepúlveda-Arques ◽  
M. Eugenia González-Rosende
Keyword(s):  
Ring Opening ◽  
Ring Closure ◽  
Theoretical Studies ◽  
Ring Opening Reactions

scholarly journals One-Pot Synthesis of Novel Dibenzoxanthenes, Diarylbutanes, and Calix[4]resorcinarenes via Consecutive Pyrrolidine Ring-Closure/Ring-Opening Reactions

2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
Andrey V. Smolobochkin ◽  
Almir S. Gazizov ◽  
Alexander R. Burilov ◽  
Michail A. Pudovik
Keyword(s):  
Ring Opening ◽  
Ring Closure ◽  
Acidic Media ◽  
Pyrrolidine Ring ◽  
One Pot ◽  
One Pot Synthesis ◽  
Ring Opening Reactions

Herein, we report the approach to the otherwise hardly accessible dibenzoxanthenes, diarylbutanes, and calix[4]resorcinarenes possessing urea moieties based on the reaction of N-(4,4-diethoxybutyl)ureas with electron-rich aromatics in strongly acidic media. Unlike the previously developed methods, the proposed approach benefits from one-pot procedure and allows to obtain the target compounds with much higher yields.

Intermediates from ring-opening reactions. Reactions of 2-chloro-5-nitropyridine and 2-chloro-3-nitropyridine with deuteroxide ion in selected solvents

1984 ◽  
Vol 62 (6) ◽  
pp. 1120-1123 ◽  
Author(s):  
John D. Reinheimer ◽  
Nicolas Sourbatis ◽  
Robert L. Lavallee ◽  
Douglas Goodwin ◽  
George L. Gould
Keyword(s):  
Ring Opening ◽  
Pyridine Ring ◽  
Ring Closure ◽  
Polar Solvents ◽  
Open Chain ◽  
Decomposition Products ◽  
Aqueous Sodium ◽  
Ring Opening Reaction ◽  
Ring Opening Reactions ◽  
Kinetics Of

Open chain intermediates from the ring-opening reaction of aqueous sodium deuteroxide (2 mol) with 2-chloro-5-nitropyridine (1 mol) and 2-chloro-3-nitropyridine (1 mol) were isolated. These intermediates were purified, analyzed for elemental composition, and characterized by various spectrophotometric techniques. The intermediate formed from 2-chloro-5-nitropyridine and two equivalents of deuteroxide ion reacts with additional deuteroxide in D2O in various polar solvents to reclose the pyridine ring. The kinetics of the ring closure reaction are reported and are supplemented with observations of salt and solvent effects upon the rate of closure. In addition, a mechanism for the ring closure is presented. The intermediate formed from 2-chloro-3-nitropyridine did not undergo a similar ring closure when reacted with additional deuteroxide, but instead formed various decomposition products. A reason for the failure of this ring closure is suggested.

Kinetische Analyse zur Umwandlung von Oxirenen oder Thiirenen und ihren offenkettigen Valenzisomeren / Kinetic Analysis for the Conversion of Oxirenes or Thiirenes and their Open-Chain Valence Isomers

1980 ◽  
Vol 35 (8) ◽  
pp. 1040-1048 ◽  
Author(s):  
Herbert Meier ◽  
Heinz Kolshorn
Keyword(s):  
Experimental Data ◽  
Kinetic Models ◽  
Ring Opening ◽  
Product Distribution ◽  
Ring Closure ◽  
Quantitative Interpretation ◽  
Open Chain ◽  
Energy Profiles ◽  
Ring Opening Reactions ◽  
Kinetische Analyse

Abstract Ring closure and ring opening reactions possess an outstanding significance for the formation and reactivity of antiaromatic heterocycles like oxirenes and thiirenes. The valence isomerisations 2 ⇆ 1 ⇆ 2' can be controlled by the product distribution 2 → P/2' → P'. A quantitative interpretation of many experimental data, published in the last years, is given on the basis of a few kinetic models, which consider thermal and photochemical pathways. Possible energy profiles of single hypersurfaces (S0 or S1) and the transition between different hypersurfaces (S1 → S0) are the most important features of these models.

Novel photosensitive polyurethanes based on photochromic dithienylethene monomers: synthesis, characterization and photophysical properties of a new film-building material for photonic applications

e-Polymers ◽  
2003 ◽  
Vol 3 (1) ◽  
Author(s):  
Arthur Thomas Bens ◽  
Radu Comanici ◽  
Bianca Gabel ◽  
Carola Kryschi ◽  
Hans-Dieter Martin ◽  
...  
Keyword(s):  
Scanning Tunneling Microscopy ◽  
Building Material ◽  
Ring Opening ◽  
Photophysical Properties ◽  
Ring Closure ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Free Standing ◽  
Polymer Backbone ◽  
Ring Opening Reactions

Abstract The synthesis of a novel photochromic dithienylethene-based polyurethane and its characterization by optical spectroscopy and scanning tunneling microscopy are presented. This linear polyurethane builds up perfect free-standing films suited for photonic applications. Moreover it may be extruded to long mechanically stable fibers. The photochromic reactions of the polyurethane, as being the electrocyclic ring-closure and ring-opening reactions of the dithienylethene unit in the polymer backbone, occur in a completely reversible and highly efficient fashion.

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