ChemInform Abstract: (PCy3)2Cl2Ru=CHR: An Efficient and Selective Reagent for the Formation of C=C-Double Bonds by Non-Polymerizing Metathesis Reactions

ChemInform ◽  
2010 ◽  
Vol 28 (27) ◽  
pp. no-no
Author(s):  
A. S. K. HASHMI
Keyword(s):  
Double Bonds ◽  
Metathesis Reactions ◽  
Selective Reagent

scholarly journals A facile route for rubber breakdown via cross metathesis reactions

2016 ◽  
Vol 18 (11) ◽  
pp. 3448-3455 ◽  
Author(s):  
R. F. Smith ◽  
S. C. Boothroyd ◽  
R. L. Thompson ◽  
E. Khosravi
Keyword(s):  
Double Bonds ◽  
Cross Metathesis ◽  
Grubbs Catalysts ◽  
Metathesis Reactions ◽  
Facile Route

Cross-linked rubbery networks can be broken down using Grubbs catalysts by cross-metathesis reactions with backbone double bonds.

scholarly journals The Influence of Various N-Heterocyclic Carbene Ligands on Activity of Nitro-Activated Olefin Metathesis Catalysts

Molecules ◽  
2020 ◽  
Vol 25 (10) ◽  
pp. 2282 ◽  
Author(s):  
Michał Pieczykolan ◽  
Justyna Czaban-Jóźwiak ◽  
Maura Malinska ◽  
Krzysztof Woźniak ◽  
Reto Dorta ◽  
...  
Keyword(s):  
High Activity ◽  
Olefin Metathesis ◽  
Double Bonds ◽  
Carbene Ligands ◽  
Grubbs Catalyst ◽  
Metathesis Reactions ◽  
Metathesis Catalysts

A set of nitro-activated ruthenium-based Hoveyda-Grubbs type olefin metathesis catalysts bearing sterically modified N-hetero-cyclic carbene (NHC) ligands have been obtained, characterised and studied in a set of model metathesis reactions. It was found that catalysts bearing standard SIMes and SIPr ligands (4a and 4b) gave the best results in metathesis of substrates with more accessible C–C double bonds. At the same time, catalysts bearing engineered naphthyl-substituted NHC ligands (4d–e) exhibited high activity towards formation of tetrasubstituted C–C double bonds, the reaction which was traditionally Achilles’ heel of the nitro-activated Hoveyda–Grubbs catalyst.

Metathesis Reactions of a Manganese Borylene Complex with Polar Heteroatom–Carbon Double Bonds: A Pathway to Previously Inaccessible Carbene Complexes

2013 ◽  
Vol 135 (23) ◽  
pp. 8726-8734 ◽  
Author(s):  
Jürgen Bauer ◽  
Holger Braunschweig ◽  
Alexander Damme ◽  
Jose Oscar Carlos ◽  
Jimenez-Halla, Thomas Kramer ◽  
...  
Keyword(s):  
Double Bonds ◽  
Carbene Complexes ◽  
Metathesis Reactions

Gold liposomes

1996 ◽  
Vol 54 ◽  
pp. 898-899
Author(s):  
James F. Hainfeld
Keyword(s):  
Direct Methods ◽  
Important Class ◽  
Double Bonds ◽  
Membrane Phospholipids ◽  
Essential Ingredient ◽  
Lipid Structures

Lipids are an important class of molecules, being found in membranes, HDL, LDL, and other natural structures, serving essential roles in structure and with varied functions such as compartmentalization and transport. Synthetic liposomes are also widely used as delivery and release vehicles for drugs, cosmetics, and other chemicals; soap is made from lipids. Lipids may form bilayer or multilammellar vesicles, micelles, sheets, tubes, and other structures. Lipid molecules may be linked to proteins, carbohydrates, or other moieties. EM study of this essential ingredient of life has lagged, due to lack of direct methods to visualize lipids without extensive alteration. OsO4 reacts with double bonds in membrane phospholipids, forming crossbridges. This has been the method of choice to both fix and stain membranes, thus far. An earlier work described the use of tungstate clusters (W11) attached to lipid moieties to form lipid structures and lipid probes.

Stereoselective Synthesis 1 Stereoselective Reactions of Carbon—Carbon Double Bonds

2011 ◽  
Author(s):  
J. G. de Vries ◽  
K. Muñiz ◽  
G. Franciò ◽  
W. Leitner ◽  
P. L. Alsters ◽  
...  
Keyword(s):  
Stereoselective Synthesis ◽  
Double Bonds ◽  
Stereoselective Reactions

Catalytic Carbonyl-Olefin Metathesis of Aliphatic Ketones: Iron(III) HomoDimers as Lewis Acidic Superelectrophiles

2018 ◽  
Author(s):  
Haley Albright ◽  
Paul S. Riehl ◽  
Christopher C. McAtee ◽  
Jolene P. Reid ◽  
Jacob R. Ludwig ◽  
...  
Keyword(s):  
Lewis Acid ◽  
Olefin Metathesis ◽  
Acid Activation ◽  
Lewis Acid Catalysts ◽  
Distinct Mode ◽  
Aliphatic Ketones ◽  
Carbon Carbon Bond ◽  
Metathesis Reactions ◽  
Acid Catalyzed

<div>Catalytic carbonyl-olefin metathesis reactions have recently been developed as a powerful tool for carbon-carbon bond</div><div>formation. However, currently available synthetic protocols rely exclusively on aryl ketone substrates while the corresponding aliphatic analogs remain elusive. We herein report the development of Lewis acid-catalyzed carbonyl-olefin ring-closing metathesis reactions for aliphatic ketones. Mechanistic investigations are consistent with a distinct mode of activation relying on the in situ formation of a homobimetallic singly-bridged iron(III)-dimer as the active catalytic species. These “superelectrophiles” function as more powerful Lewis acid catalysts that form upon association of individual iron(III)-monomers. While this mode of Lewis acid activation has previously been postulated to exist, it has not yet been applied in a catalytic setting. The insights presented are expected to enable further advancement in Lewis acid catalysis by building upon the activation principle of “superelectrophiles” and broaden the current scope of catalytic carbonyl-olefin metathesis reactions.</div>

Nickel-Catalyzed Inter- and Intramolecular Carbon-Sulfur Bond Metathesis by Reversible Arylation

2019 ◽  
Author(s):  
Tristan Delcaillau ◽  
Alessandro Bismuto ◽  
Zhong Lian ◽  
Bill Morandi
Keyword(s):  
Good Yield ◽  
Functional Group ◽  
Product Formation ◽  
Single Bond ◽  
Ring Closing Metathesis ◽  
Catalytic Systems ◽  
Metathesis Reactions ◽  
New Applications ◽  
Further Development ◽  
Sulfur Bond

A nickel-catalyzed carbon-sulfur bond metathesis has been developed to access high-value thioethers. 1,2-bis(dicyclohexylphosphino)ethane (dcype) is essential to promote this highly functional group tolerant reaction. Further, synthetically challenging macrocycles could be obtained in good yield in an unusual example of ring-closing metathesis which does not involve alkene bonds. In-depth organometallic studies support a reversible Ni(0)-Ni(II) pathway to product formation. Overall, this work does not only disclose a more sustainable and more functional group tolerant alternative to previous catalytic systems based on Pd, but also presents new applications and mechanistic information which are highly relevant to the further development and application of unusual single bond metathesis reactions.

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