The Ruthenium-Catalyzed Domino Cross Enyne Metathesis/Ring-Closing Metathesis in the Synthesis of Enantioenriched Nitrogen-Containing Heterocycles

2020 ◽  
Vol 2020 (27) ◽  
pp. 4193-4207 ◽  
Author(s):  
Alberto Llobat ◽  
Jorge Escorihuela ◽  
Daniel M. Sedgwick ◽  
Miriam Rodenes ◽  
Raquel Román ◽  
...  
Keyword(s):  
Enyne Metathesis ◽  
Ring Closing Metathesis

scholarly journals Synthesis of fluorinated δ-lactams via cycloisomerization of gem-difluoropropargyl amides

2010 ◽  
Vol 6 ◽  
Author(s):  
Satoru Arimitsu ◽  
Gerald B Hammond
Keyword(s):  
Building Blocks ◽  
Alder Reaction ◽  
Diels Alder ◽  
Tandem Reaction ◽  
Enyne Metathesis ◽  
Metathesis Reaction ◽  
Ring Closing Metathesis ◽  
Diels Alder Reaction

gem-Difluoro-1,7-enyne amides are suitable building blocks for the synthesis of difluorodihydropyridinones via a ring-closing metathesis reaction, and of 4,4-difluoro-3-oxoisoquinolines through a ring-closing metathesis–enyne metathesis tandem reaction. These products, in turn, undergo a Diels–Alder reaction to yield heterotricyclic systems in moderate to good yields.

scholarly journals Ring-closing metathesis of prochiral oxaenediynes to racemic 4-alkenyl-2-alkynyl-3,6-dihydro-2H-pyrans

2020 ◽  
Vol 16 ◽  
pp. 2757-2768
Author(s):  
Viola Kolaříková ◽  
Markéta Rybáčková ◽  
Martin Svoboda ◽  
Jaroslav Kvíčala
Keyword(s):  
Triple Bond ◽  
Building Blocks ◽  
Ester Group ◽  
Alder Reaction ◽  
Diels Alder ◽  
Side Reactions ◽  
Enyne Metathesis ◽  
Ring Closing Metathesis ◽  
2Nd Generation ◽  
Diels Alder Reaction

The prochiral 4-(allyloxy)hepta-1,6-diynes, optionally modified in the positions 1 and 7 with an alkyl or ester group, undergo a chemoselective ring-closing enyne metathesis yielding racemic 4-alkenyl-2-alkynyl-3,6-dihydro-2H-pyrans. Among the catalysts tested, Grubbs 1st generation precatalyst in the presence of ethene (Mori conditions) gave superior results compared to the more stable Grubbs or Hoveyda–Grubbs 2nd generation precatalysts. This is probably caused by a suppression of the subsequent side-reactions of the enyne metathesis product with ethene. On the other hand, the 2nd generation precatalysts gave better yields in the absence of ethene. The metathesis products, containing both a triple bond and a conjugated system, can be successfully orthogonally modified. For example, the metathesis product of 5-(allyloxy)nona-2,7-diyne reacted chemo- and stereoselectively in a Diels–Alder reaction with N-phenylmaleimide affording the tricyclic products as a mixture of two separable diastereoisomers, the configuration of which was estimated by DFT computations. The reported enediyne metathesis paves the way to the enantioselective enyne metathesis yielding chiral building blocks for compounds with potential biological activity, e.g., norsalvinorin or cacospongionolide B.

scholarly journals Olefin metathesis in nano-sized systems

2011 ◽  
Vol 7 ◽  
pp. 94-103 ◽  
Author(s):  
Didier Astruc ◽  
Abdou K Diallo ◽  
Sylvain Gatard ◽  
Liyuan Liang ◽  
Cátia Ornelas ◽  
...  
Keyword(s):  
Olefin Metathesis ◽  
Covalent Attachment ◽  
Enyne Metathesis ◽  
Ring Closing Metathesis ◽  
Cross Metathesis ◽  
Metathesis Reactions ◽  
Nano Catalysts

The interplay between olefin metathesis and dendrimers and other nano systems is addressed in this mini review mostly based on the authors’ own contributions over the last decade. Two subjects are presented and discussed: (i) The catalysis of olefin metathesis by dendritic nano-catalysts via either covalent attachment (ROMP) or, more usefully, dendrimer encapsulation – ring closing metathesis (RCM), cross metathesis (CM), enyne metathesis reactions (EYM) – for reactions in water without a co-solvent and (ii) construction and functionalization of dendrimers by CM reactions.

ChemInform Abstract: Synthesis of Acyloxy-Semicyclic Dienes Using an Enyne Metathesis/Ring Closing Metathesis Approach.

ChemInform ◽  
2015 ◽  
Vol 46 (26) ◽  
pp. no-no
Author(s):  
Jui Thiang Brian Kueh ◽  
Lindon W. K. Moodie ◽  
Nigel T. Lucas ◽  
David S. Larsen
Keyword(s):  
Enyne Metathesis ◽  
Ring Closing Metathesis

scholarly journals Ring closing metathesis of prochiral oxaenediynes to racemic 4-alkenyl-2-alkynyl-3,6-dihydro-2H-pyrans

2020 ◽  
Author(s):  
Viola Kolaříková ◽  
Markéta Rybáčková ◽  
Martin Svoboda ◽  
Jaroslav Kvíčala
Keyword(s):  
Triple Bond ◽  
Building Blocks ◽  
Ester Group ◽  
Alder Reaction ◽  
Diels Alder ◽  
The Other ◽  
Side Reactions ◽  
Enyne Metathesis ◽  
Ring Closing Metathesis ◽  
Diels Alder Reaction

Prochiral 4-(allyloxy)hepta-1,6-diynes, optionally modified in the positions 1 and 7 with an alkyl or ester group, undergo chemoselective ring closing enyne metathesis yielding racemic 4-alkenyl-2-alkynyl-3,6-dihydro-2H-pyrans. Among the catalysts tested, Grubbs 1st generation precatalyst in the presence of ethene (Mori conditions) gave superior results compared to more stable Grubbs or Hoveyda-Grubbs 2nd generation precatalysts. This is probably caused by suppression of subsequent side-reactions of the enyne metathesis product with ethene. On the other hand, 2nd generation precatalysts gave better yields in the absence of ethene. The metathesis products, containing both triple bond and conjugated system, can be successfully orthogonally modified. For example, metathesis product of 5-(allyloxy)nona-2,7-diyne reacted chemo- and stereoselectively by Diels-Alder reaction with N-phenylmaleimide affording tricyclic products as the mixture of two separable diastereoisomers, the configuration of which was estimated by DFT computations. The reported enediyne metathesis paves the way to enantioselective enyne metathesis yielding chiral building blocks for compounds with potential biological activity, e.g. norsalvinorin or cacospongionolide B.

Synthesis of Acyloxy-Semicyclic Dienes Using an Enyne Metathesis/Ring Closing Metathesis Approach

2015 ◽  
Vol 2015 (7) ◽  
pp. 1485-1490 ◽  
Author(s):  
Jui Thiang Brian Kueh ◽  
Lindon W. K. Moodie ◽  
Nigel T. Lucas ◽  
David S. Larsen
Keyword(s):  
Enyne Metathesis ◽  
Ring Closing Metathesis

scholarly journals The catalytic performance of Ru–NHC alkylidene complexes: PCy3 versus pyridine as the dissociating ligand

2010 ◽  
Vol 6 ◽  
pp. 1188-1198 ◽  
Author(s):  
Stefan Krehl ◽  
Diana Geißler ◽  
Sylvia Hauke ◽  
Oliver Kunz ◽  
Lucia Staude ◽  
...  
Keyword(s):  
Catalytic Performance ◽  
Enyne Metathesis ◽  
Pyridine Ligand ◽  
Ring Closing Metathesis ◽  
Similar Activity ◽  
Cross Metathesis ◽  
Pyridine Complex ◽  
Metathesis Reactions ◽  
Alkylidene Complexes

The catalytic performance of NHC-ligated Ru-indenylidene or benzylidene complexes bearing a tricyclohexylphosphine or a pyridine ligand in ring closing metathesis (RCM), cross metathesis, and ring closing enyne metathesis (RCEYM) reactions is compared. While the PCy3 complexes perform significantly better in RCM and RCEYM reactions than the pyridine complex, all catalysts show similar activity in cross metathesis reactions.

scholarly journals Latent ruthenium–indenylidene catalysts bearing a N-heterocyclic carbene and a bidentate picolinate ligand

2015 ◽  
Vol 11 ◽  
pp. 1541-1546 ◽  
Author(s):  
Thibault E Schmid ◽  
Florian Modicom ◽  
Adrien Dumas ◽  
Etienne Borré ◽  
Loic Toupet ◽  
...  
Keyword(s):  
Bronsted Acid ◽  
Brønsted Acid ◽  
Enyne Metathesis ◽  
Ring Closing Metathesis ◽  
Cross Metathesis ◽  
Brönsted Acid ◽  
Metathesis Reactions

A silver-free methodology was developed for the synthesis of unprecedented N-heterocyclic carbene ruthenium indenylidene complexes bearing a bidentate picolinate ligand. The highly stable (SIPr)(picolinate)RuCl(indenylidene) complex 4a (SIPr = 1,3-bis(2-6-diisopropylphenyl)imidazolidin-2-ylidene) demonstrated excellent latent behaviour in ring closing metathesis (RCM) reaction and could be activated in the presence of a Brønsted acid. The versatility of the catalyst 4a was subsequently demonstrated in RCM, cross-metathesis (CM) and enyne metathesis reactions.

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