The Experts below are selected from a list of 13104 Experts worldwide ranked by ideXlab platform
Robert H Grubbs - One of the best experts on this subject based on the ideXlab platform.
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Synthesis of coumarins by Ring-Closing Metathesis*
Pure and Applied Chemistry, 2009Co-Authors: Arnab K. Chatterjee, F. D. Toste, Steven D. Goldberg, Robert H GrubbsAbstract:Investigations into olefin Ring-Closing Metathesis (RCM) have led to a general method for the synthesis of coumarins. Catalysts with higher activity, such as the second-gen- eration ruthenium catalyst, promote the intramolecular reaction between two-electron defi- cient olefins. This method allows for convenient access to a variety of coumarins substituted at both the 3- and 4-positions, as well as a tetrasubstituted example.
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highly efficient ruthenium catalysts for the formation of tetrasubstituted olefins via Ring Closing Metathesis
Organic Letters, 2007Co-Authors: Ian C Stewart, Alexandre A. Pletnev, Robert H Grubbs, Jacob M Berlin, Yann SchrodiAbstract:A series of ruthenium-based Metathesis catalysts with N-heterocyclic carbene (NHC) ligands have been prepared in which the N-aryl groups have been changed from mesityl to mono-ortho-substituted phenyl (e.g., tolyl). These new catalysts offer an exceptional increase in activity for the formation of tetrasubstituted olefins via Ring-Closing Metathesis (RCM), while maintaining high levels of activity in Ring-Closing Metathesis (RCM) reactions that generate di- and trisubstituted olefins.
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ruthenium catalyzed Ring Closing Metathesis to form tetrasubstituted olefins
Organic Letters, 2007Co-Authors: Jacob M Berlin, Katie Campbell, Tobias Ritter, Timothy W Funk, Anatoly Chlenov, Robert H GrubbsAbstract:Increased efficiency for Ring-Closing Metathesis to form tetrasubstituted olefins using N-heterocyclic carbene ligated ruthenium catalysts was achieved by reducing the size of the substituents at the ortho positions of the N-bound aryl Rings.
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Total synthesis of (−)- and (±)-frontalin via Ring-Closing Metathesis
Tetrahedron Letters, 1999Co-Authors: Matthias Scholl, Robert H GrubbsAbstract:Abstract Racemic and enantiopure targets containing the 6,8-dioxabicyclo [3.2.1]octane skeleton, can be conveniently synthesized from monocyclic diene precursors using an intramolecular ruthenium-catalyzed Ring-Closing Metathesis reaction as the key step.
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Formation of bridged bicycloalkenes via Ring Closing Metathesis
Chemical Communications, 1998Co-Authors: Andrew Morehead, Robert H GrubbsAbstract:Ring Closing Metathesis may be used in the formation of small Ring bicycloalkenes from monocyclic diene precursors.
Jacob M Berlin - One of the best experts on this subject based on the ideXlab platform.
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highly efficient ruthenium catalysts for the formation of tetrasubstituted olefins via Ring Closing Metathesis
Organic Letters, 2007Co-Authors: Ian C Stewart, Alexandre A. Pletnev, Robert H Grubbs, Jacob M Berlin, Yann SchrodiAbstract:A series of ruthenium-based Metathesis catalysts with N-heterocyclic carbene (NHC) ligands have been prepared in which the N-aryl groups have been changed from mesityl to mono-ortho-substituted phenyl (e.g., tolyl). These new catalysts offer an exceptional increase in activity for the formation of tetrasubstituted olefins via Ring-Closing Metathesis (RCM), while maintaining high levels of activity in Ring-Closing Metathesis (RCM) reactions that generate di- and trisubstituted olefins.
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ruthenium catalyzed Ring Closing Metathesis to form tetrasubstituted olefins
Organic Letters, 2007Co-Authors: Jacob M Berlin, Katie Campbell, Tobias Ritter, Timothy W Funk, Anatoly Chlenov, Robert H GrubbsAbstract:Increased efficiency for Ring-Closing Metathesis to form tetrasubstituted olefins using N-heterocyclic carbene ligated ruthenium catalysts was achieved by reducing the size of the substituents at the ortho positions of the N-bound aryl Rings.
Yann Schrodi - One of the best experts on this subject based on the ideXlab platform.
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highly efficient ruthenium catalysts for the formation of tetrasubstituted olefins via Ring Closing Metathesis
Organic Letters, 2007Co-Authors: Ian C Stewart, Alexandre A. Pletnev, Robert H Grubbs, Jacob M Berlin, Yann SchrodiAbstract:A series of ruthenium-based Metathesis catalysts with N-heterocyclic carbene (NHC) ligands have been prepared in which the N-aryl groups have been changed from mesityl to mono-ortho-substituted phenyl (e.g., tolyl). These new catalysts offer an exceptional increase in activity for the formation of tetrasubstituted olefins via Ring-Closing Metathesis (RCM), while maintaining high levels of activity in Ring-Closing Metathesis (RCM) reactions that generate di- and trisubstituted olefins.
Stephen F. Martin - One of the best experts on this subject based on the ideXlab platform.
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Applications of Ring Closing Metathesis. Total synthesis of (±)-pseudotabersonine
Tetrahedron, 2015Co-Authors: Bo Cheng, James D. Sunderhaus, Stephen F. MartinAbstract:A novel approach to the Aspidosperma family of alkaloids was developed and applied to a concise total synthesis of (±)-pseudotabersonine that was accomplished in 11 steps. Key transformations include a stepwise variant of a Mannich-like multicomponent assembly process, a double Ring-Closing Metathesis sequence, and a one-pot deprotection/cyclization reaction.
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Eantioselective Synthesis of (+)-Isolysergol via Ring-Closing Metathesis.
ChemInform, 2010Co-Authors: Jason A. Deck, Stephen F. MartinAbstract:The approach includes a microwave-mediated diastereomeric Ring-Closing Metathesis in the presence of a chiral molybdenum catalyst to create the D Ring and the stereocenter at C-8.
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enantioselective synthesis of isolysergol via Ring Closing Metathesis
Organic Letters, 2010Co-Authors: Jason A. Deck, Stephen F. MartinAbstract:The first enantioselective synthesis of (+)-isolysergol was completed in 12 steps from commercially available materials by a novel approach that features a late stage microwave-mediated, diastereomeric Ring-Closing Metathesis catalyzed by a chiral molybdenum catalyst to simultaneously form the D Ring and set the stereocenter at C(8).
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Enantioselective Synthesis of (+)-Isolysergol via Ring-Closing Metathesis
Organic Letters, 2010Co-Authors: Jason A. Deck, Stephen F. MartinAbstract:The first enantioselective synthesis of (+)-isolysergol was completed in 12 steps from commercially available materials by a novel approach that features a late stage microwave-mediated, diastereomeric Ring-Closing Metathesis catalyzed by a chiral molybdenum catalyst to simultaneously form the D Ring and set the stereocenter at C(8).
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Ring-Closing Metathesis: A facile construct for alkaloid synthesis*
Pure and Applied Chemistry, 2009Co-Authors: Stephen F. MartinAbstract:Ring-Closing Metathesis has been found to be a highly effective reaction for the synthesis of functionalized, bridged nitrogen heterocycles. The utility of the process has been established in several case studies, including a facile synthesis of the tropane Ring system and efficient, enantioselective syntheses of the natural products (-)-peduncularine and (+)-ana- toxin-a.
Masamichi Ogasawara - One of the best experts on this subject based on the ideXlab platform.
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enantioselective synthesis of macrocyclic heterobiaryl derivatives of molecular asymmetry by molybdenum catalyzed asymmetric Ring Closing Metathesis
Angewandte Chemie, 2015Co-Authors: Yoichi Okayama, Satoru Tsuji, Yuka Toyomori, Atsunori Mori, Sachie Arae, Wei Yi Wu, Tamotsu Takahashi, Masamichi OgasawaraAbstract:: Winding vine-shaped molecular asymmetry is induced by enantioselective Ring-Closing Metathesis with a chiral molybdenum catalyst. The reaction proceeds under mild conditions through an E-selective Ring-Closing Metathesis leading to macrocyclic bisazoles with enantioselectivities of up to 96% ee.
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Enantioselective Synthesis of Macrocyclic Heterobiaryl Derivatives of Molecular Asymmetry by Molybdenum‐Catalyzed Asymmetric Ring‐Closing Metathesis
Angewandte Chemie, 2015Co-Authors: Yoichi Okayama, Satoru Tsuji, Yuka Toyomori, Atsunori Mori, Sachie Arae, Wei Yi Wu, Tamotsu Takahashi, Masamichi OgasawaraAbstract:: Winding vine-shaped molecular asymmetry is induced by enantioselective Ring-Closing Metathesis with a chiral molybdenum catalyst. The reaction proceeds under mild conditions through an E-selective Ring-Closing Metathesis leading to macrocyclic bisazoles with enantioselectivities of up to 96% ee.
