scholarly journals Transformations of terpenes and terpenoids via carbon–carbon double bond metathesis

2018 ◽  
Vol 8 (16) ◽  
pp. 3989-4004 ◽  
Author(s):  
Christian Bruneau ◽  
Cédric Fischmeister ◽  
Dalmo Mandelli ◽  
Wagner A. Carvalho ◽  
Eduardo N. dos Santos ◽  
...  
Keyword(s):  
Double Bond ◽  
Olefin Metathesis ◽  
Ring Opening ◽  
Ring Closing Metathesis ◽  
Cross Metathesis ◽  
Carbon Double Bond ◽  
Review Reports

The review reports on transformations of unsaturated terpenes and terpenoids via olefin metathesis processes including ring closing metathesis of dienes, cross metathesis with functional olefins and ethenolysis, and ring opening metathesis as well as ring opening/cross metathesis.

scholarly journals Halide exchanged Hoveyda-type complexes in olefin metathesis

2010 ◽  
Vol 6 ◽  
pp. 1091-1098 ◽  
Author(s):  
Julia Wappel ◽  
César A Urbina-Blanco ◽  
Mudassar Abbas ◽  
Jörg H Albering ◽  
Robert Saf ◽  
...  
Keyword(s):  
Olefin Metathesis ◽  
Ring Opening ◽  
Catalytic Performance ◽  
Ring Closing Metathesis ◽  
Cross Metathesis ◽  
Metathesis Reactions ◽  
Metathesis Catalysts

The aims of this contribution are to present a straightforward synthesis of 2nd generation Hoveyda-type olefin metathesis catalysts bearing bromo and iodo ligands, and to disclose the subtle influence of the different anionic co-ligands on the catalytic performance of the complexes in ring opening metathesis polymerisation, ring closing metathesis, enyne cycloisomerisation and cross metathesis reactions.

Reactions of 4-Pyrones with Azomethine Ylides as a Chemo­selective Method for the Construction of Multisubstituted Pyrano[2,3-c]pyrrolidines

Synthesis ◽  
2021 ◽  
Author(s):  
Dmitrii L. Obydennov ◽  
Vyacheslav D. Steben’kov ◽  
Konstantin L. Obydennov ◽  
Sergey A. Usachev ◽  
Vladimir S. Moshkin ◽  
...  
Keyword(s):  
Double Bond ◽  
Ring Opening ◽  
Azomethine Ylides ◽  
Azomethine Ylide ◽  
Dipolar Cycloaddition ◽  
Computational Studies ◽  
Carbon Double Bond ◽  
Reactivity Indexes ◽  
Reaction Proceeds

Abstract4-Pyrones bearing electron-donating and electron-withdrawing groups react with nonstabilized azomethine ylides to form pyrano[2,3-c]pyrrolidines in moderate to good yields. The reaction proceeds chemoselectively as a 1,3-dipolar cycloaddition of the azomethine ylide at the carbon–carbon double bond of the pyrone activated by the electron-withdrawing substituent. The reactivity of 4-pyrones toward azomethine ylides was rationalized by computational studies with the use of reactivity indexes. The pyrano[2,3-c]pyrrolidine moiety could be modified, for example by a ring-opening transformation under the action of hydrazine to provide pyrazolyl-substituted pyrrolidines.

scholarly journals Ring-closing-metathesis-based synthesis of annellated coumarins from 8-allylcoumarins

2018 ◽  
Vol 14 ◽  
pp. 2991-2998 ◽  
Author(s):  
Christiane Schultze ◽  
Bernd Schmidt
Keyword(s):  
Double Bond ◽  
Olefin Metathesis ◽  
Claisen Rearrangement ◽  
Allylic Oxidation ◽  
Allyl Ether ◽  
Ring Closing Metathesis ◽  
Wittig Olefination

8-Allylcoumarins are conveniently accessible through a microwave-promoted tandem Claisen rearrangement/Wittig olefination/cyclization sequence. They serve as a versatile platform for the annellation of five- to seven-membered rings using ring-closing olefin metathesis (RCM). Furano-, pyrano-, oxepino- and azepinocoumarins were synthesized from the same set of precursors using Ru-catalyzed double bond isomerizations and RCM in a defined order. One class of products, pyrano[2,3-f]chromene-2,8-diones, were inaccessible through direct RCM of an acrylate, but became available from the analogous allyl ether via an assisted tandem catalytic RCM/allylic oxidation sequence.

scholarly journals Application of olefin metathesis in the synthesis of functionalized polyhedral oligomeric silsesquioxanes (POSS) and POSS-containing polymeric materials

2019 ◽  
Vol 15 ◽  
pp. 310-332 ◽  
Author(s):  
Patrycja Żak ◽  
Cezary Pietraszuk
Keyword(s):  
Olefin Metathesis ◽  
Ring Opening ◽  
Polymeric Materials ◽  
Acyclic Diene Metathesis ◽  
Polyhedral Oligomeric Silsesquioxanes ◽  
Ring Opening Metathesis Polymerization ◽  
Metathesis Polymerization ◽  
Cross Metathesis ◽  
Terminal Olefins ◽  
Synthesized Materials

This mini-review summarizes the applications of olefin metathesis in synthesis and functionalization of polyhedral oligomeric silsesquioxanes (POSS) and POSS-containing polymeric materials. Three types of processes, i.e., cross metathesis (CM) of vinyl-substituted POSS with terminal olefins, acyclic diene metathesis (ADMET) copolymerization of divinyl-substituted POSS with α,ω-dienes and ring-opening metathesis polymerization (ROMP) of POSS-substituted norbornene (or other ROMP susceptible cycloolefins) are discussed. Emphasis was put on the synthetic and catalytic aspects rather than on the properties and applications of synthesized materials.

scholarly journals New library of aminosulfonyl-tagged Hoveyda–Grubbs type complexes: Synthesis, kinetic studies and activity in olefin metathesis transformations

2010 ◽  
Vol 6 ◽  
pp. 1159-1166 ◽  
Author(s):  
Etienne Borré ◽  
Frederic Caijo ◽  
Christophe Crévisy ◽  
Marc Mauduit
Keyword(s):  
Olefin Metathesis ◽  
Kinetic Studies ◽  
Ring Closing Metathesis ◽  
Good Tolerance ◽  
Cross Metathesis ◽  
Activity Enhancement ◽  
Selection Of

Seven novel Hoveyda–Grubbs precatalysts bearing an aminosulfonyl function are reported. Kinetic studies indicate an activity enhancement compared to Hoveyda’s precatalyst. A selection of these catalysts was investigated with various substrates in ring-closing metathesis of dienes or enynes and cross metathesis. The results demonstrate that these catalysts show a good tolerance to various chemical functions.

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