Ruthenium catalysts bearing a benzimidazolylidene ligand for the metathetical ring-closure of tetrasubstituted cycloolefins

2015 ◽  
Vol 44 (21) ◽  
pp. 9744-9755 ◽  
Author(s):  
Yannick Borguet ◽  
Guillermo Zaragoza ◽  
Albert Demonceau ◽  
Lionel Delaude
Keyword(s):  
Second Generation ◽  
Ruthenium Catalysts ◽  
Ring Closure ◽  
Ring Closing Metathesis ◽  
Highly Efficient ◽  
Alkylidene Complexes

Second-generation ruthenium–alkylidene complexes featuring the 1,3-di(2-tolyl)benzimidazol-2-ylidene ligand (BTol) are highly efficient catalysts for the synthesis of tetrasubstituted cycloolefins via ring-closing metathesis (RCM).

Highly Efficient Ruthenium Catalysts for the Formation of Tetrasubstituted Olefins via Ring-Closing Metathesis

2007 ◽  
Vol 9 (8) ◽  
pp. 1589-1592 ◽  
Author(s):  
Ian C. Stewart ◽  
Thay Ung ◽  
Alexandre A. Pletnev ◽  
Jacob M. Berlin ◽  
Robert H. Grubbs ◽  
...  
Keyword(s):  
Ruthenium Catalysts ◽  
Ring Closing Metathesis ◽  
Highly Efficient ◽  
Tetrasubstituted Olefins

scholarly journals Highly Efficient Ruthenium Catalysts for the Formation of Tetrasubstituted Olefins via Ring-Closing Metathesis.

ChemInform ◽  
2007 ◽  
Vol 38 (35) ◽  
Author(s):  
Ian C. Stewart ◽  
Thay Ung ◽  
Alexandre A. Pletnev ◽  
Jacob M. Berlin ◽  
Robert H. Grubbs ◽  
...  
Keyword(s):  
Ruthenium Catalysts ◽  
Ring Closing Metathesis ◽  
Highly Efficient ◽  
Tetrasubstituted Olefins

A Highly Efficient Synthesis of Lamellarins K and L by the Michael Addition/Ring-Closure Reaction of Benzyldihydroisoquinoline Derivatives with Ethoxycarbonyl-β-nitrostyrenes

2004 ◽  
Vol 116 (7) ◽  
pp. 884-886 ◽  
Author(s):  
Poonsakdi Ploypradith ◽  
Chulabhorn Mahidol ◽  
Poolsak Sahakitpichan ◽  
Siriporn Wongbundit ◽  
Somsak Ruchirawat
Keyword(s):  
Michael Addition ◽  
Ring Closure ◽  
Efficient Synthesis ◽  
Highly Efficient ◽  
The Michael Addition

Ring-closing Metathesis in Peptides - the Sting is in the Tail!

2011 ◽  
Vol 64 (6) ◽  
pp. 806 ◽  
Author(s):  
Bianca J. van Lierop ◽  
Christoph Bornschein ◽  
W. Roy Jackson ◽  
Andrea J. Robinson
Keyword(s):  
Peptide Synthesis ◽  
Solid Phase ◽  
Solid Phase Peptide Synthesis ◽  
Ring Closure ◽  
Ring Closing Metathesis ◽  
Single Ring ◽  
Aggregation Phenomena

Performing ring-closing metathesis on resin-bound peptides provides an expedient route to carbocyclic peptidomimetics of medicinal interest. Some sequences are highly resistant to metathesis and special strategies need to be employed to promote viable ring closure. This paper describes an on-resin, alternating solid-phase peptide synthesis-catalysis method to overcome deleterious aggregation phenomena. It can be used to promote high yielding single-ring closures and regioselective multi-ring construction in peptides.

Alkene and Alkyne Metathesis: Phaseolinic Acid (Selvakumar), Methyl 7-Dihydro-trioxacarcinoside B (Koert), Arglabin (Reiser) and Amphidinolide V (Fürstner)

2011 ◽  
Author(s):  
Douglass Taber
Keyword(s):  
Organic Synthesis ◽  
Second Generation ◽  
Secondary Alcohol ◽  
Allylic Alcohol ◽  
Alkyne Metathesis ◽  
Max Planck ◽  
Ring Closing Metathesis ◽  
Relative Configuration ◽  
Stereogenic Centers ◽  
Ru Complexes

As N. Selvakumar of Dr. Reddy’s Laboratories, Ltd., Hyderabad approached (Tetrahedron Lett. 2007, 48, 2021) the synthesis of phaseolinic acid 6, there was some concern about the projected cyclization of 2 to 3, as this would involve the coupling of two electron-deficient alkenes. In fact, the Ru-mediated ring-closing metathesis proceeded efficiently. The product unsaturated lactone 3 could be reduced selectively to either the trans product 4 or the cis product 5. There has been relatively little work on the synthesis of the higher branched sugars, such as the octalose 13, a component of several natural products. The synthesis of 13 (Organic Lett. 2007, 9, 4777) by Ulrich Koert of the Philipps-University Marburg also began with a Baylis-Hillman product, the easily-resolved secondary alcohol 8. As had been observed in other contexts, cyclization of the protected allylic alcohol 9a failed, but cyclization of the free alcohol 9b proceeded smoothly. V-directed epoxidation then set the relative configuration of the stereogenic centers on the ring. Ring-closing metathesis to construct tetrasubstituted alkenes has been a challenge, and specially-designed Ru complexes have been put forward specifically for this transformation. Oliver Reiser of the Universität Regensburg was pleased to observe (Angew. Chem. Int. Ed. 2007, 46, 6361) that the second-generation Grubbs catalyst itself worked well for the cyclization of 17 to 18. Again in this synthesis, catalytic V was used to direct the relative configuration of the epoxide. Intramolecular alkyne metathesis is now well-established as a robust and useful method for organic synthesis. It was also known that Ru-mediated metathesis of an alkyne with ethylene could lead to the diene. The question facing (Angew. Chem. Int. Ed . 2007, 46, 5545) Alois Fürstner of the Max-Planck-Institut, Mülheim was whether these transformations could be carried out on the very delicate epoxy alkene 21. In fact, the transformations of 21 to 22 and of 22 to 23 proceeded well, setting the stage for the total synthesis of Amphidinolide V 25.

Highly efficient homogeneous and heterogenized ruthenium catalysts for transfer hydrogenation of carbonyl compounds

RSC Advances ◽  
2014 ◽  
Vol 4 (53) ◽  
pp. 27955-27962 ◽  
Author(s):  
S. Ganesamoorthy ◽  
P. Jerome ◽  
K. Shanmugasundaram ◽  
R. Karvembu
Keyword(s):  
Carbonyl Compounds ◽  
Ruthenium Catalysts ◽  
Transfer Hydrogenation ◽  
Highly Efficient

[Ru(acac)2(CH3CN)2] and its SiO2 immobilized form were found to be efficient catalysts for the transfer hydrogenation of carbonyl compounds.

Second generation OLED devices and systems: inline evaporation, highly efficient OLED devices, and novel driver/controller ASICs

2005 ◽  
Author(s):  
Joerg Amelung ◽  
Michael Toerker ◽  
Claus Luber ◽  
Michael Eritt ◽  
Yuto Tomita ◽  
...  
Keyword(s):  
Second Generation ◽  
Highly Efficient
Sign in / Sign up

Export Citation Format

Share Document