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Steven T Diver - One of the best experts on this subject based on the ideXlab platform.
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Enyne Metathesis/Brønsted acid-promoted heterocyclization.
Journal of Organic Chemistry, 2009Co-Authors: Kyle P. Kalbarczyk, Steven T DiverAbstract:The “one-pot” synthesis of nitrogen heterocycles and an oxygen heterocycle by Enyne Metathesis and in situ cyclization is reported.
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Enyne Metathesis bronsted acid promoted heterocyclization
Journal of Organic Chemistry, 2009Co-Authors: Kyle P. Kalbarczyk, Steven T DiverAbstract:The "one-pot" synthesis of nitrogen heterocycles and an oxygen heterocycle by Enyne Metathesis and in situ cyclization is reported.
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Selective tandem Enyne Metathesis for the synthesis of functionalized cycloheptadienes
Tetrahedron, 2008Co-Authors: Steven T Diver, Daniel A. Clark, Amol A. KulkarniAbstract:Abstract The regio- and site-selective ring expansion of dienes and the regioselective ring expansion of substituted cyclopentenes provide 1,3-cycloheptadienes by Enyne Metathesis under methylene-free conditions. Site-selectivity results from differential ring strain among two different cycloalkenes in diene reactants. The high regioselectivity found in the ring expansion of tetrahydroindene (THI) is explained on the basis of a selective ring opening by the second generation Grubbs' ruthenium carbene complex. The ring opening of substituted cyclopentenes and cyclopentene contained in a bicyclic ring system was also achieved. The ring expansion of bicyclic dienes provided seven-membered dienes contained in the bicyclo[5.2.0]nonane ring system. Details of the structural analysis are also discussed. A mechanistic analysis is provided to account for the data presented herein.
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Ruthenium Vinyl Carbene Intermediates in Enyne Metathesis.
Coordination chemistry reviews, 2007Co-Authors: Steven T DiverAbstract:This review provides an overview of ruthenium vinyl carbene reactivity as it relates to Enyne Metathesis. Methods for the synthesis of Metathesis-active and Metathesis-inactive complexes are also summarized. Some of the early hypotheses about vinyl carbene intermediates in Enyne metatheses were tested in the arena of synthetic chemistry and subsequently led to mechanistic studies. In these two areas, studies from the author's labs are described. There are still many unresolved questions in Enyne Metathesis that trace back to vinyl carbene reactivity. Hopefully this review will stimulate further investigation into vinyl carbene reactivity which should further refine our understanding of catalytic Enyne Metathesis.
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Tandem Enyne Metathesis and Claisen Rearrangement: A Versatile Approach to Conjugated Dienes of Variable Substitution Patterns
Journal of the American Chemical Society, 2006Co-Authors: Daniel A. Clark, Kyle P. Kalbarczyk, Amol A. Kulkarni, Bryan M. Schertzer, Steven T DiverAbstract:To extend the versatility of the ruthenium carbene-promoted Enyne Metathesis, it was combined with an Ireland ester enolate Claisen rearrangement. This reaction sequence provided conjugated dienes of higher substitution pattern than that obtained through a cross-Enyne Metathesis alone. The Ireland−Claisen was conducted across both acyclic and cyclic dienes produced from cross-Metathesis and methylene-free Enyne Metathesis, respectively. In the case of cyclodienes, the Ireland−Claisen rearrangement produced s-trans locked dienes which underwent mode-selective ene reaction. The tandem, sequential use of the Ireland−Claisen rearrangement also proved suitable for chirality transfer originating from chiral propargylic alcohols. Last, the tandem Metathesis/Ireland−Claisen was utilized to access 4-substituted-3,5-cyclohexadiene diol derivatives, which are valuable chiral intermediates for natural product synthesis. The combination of this pericyclic reaction with a catalytic Metathesis reaction extends the versa...
Marc L. Snapper - One of the best experts on this subject based on the ideXlab platform.
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ruthenium catalyzed tandem Enyne Metathesis hydrovinylation
ChemInform, 2010Co-Authors: Jason Gavenonis, Ruben V. Arroyo, Marc L. SnapperAbstract:In situ modification of Grubbs′ first-generation Metathesis catalyst allows for a one-pot tandem ruthenium-catalyzed Enyne Metathesis/hydrovinylation sequence.
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Ruthenium‐Catalyzed Tandem Enyne Metathesis/Hydrovinylation.
ChemInform, 2010Co-Authors: Jason Gavenonis, Ruben V. Arroyo, Marc L. SnapperAbstract:In situ modification of Grubbs′ first-generation Metathesis catalyst allows for a one-pot tandem ruthenium-catalyzed Enyne Metathesis/hydrovinylation sequence.
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ruthenium catalyzed tandem Enyne Metathesis hydrovinylation
Chemical Communications, 2010Co-Authors: Jason Gavenonis, Ruben V. Arroyo, Marc L. SnapperAbstract:In situ modification of Grubbs' first-generation Metathesis catalyst allows for a tandem Enyne Metathesis/hydrovinylation that is complementary to the regioselectivity of known ruthenium-catalyzed hydrovinylations.
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Ruthenium-catalyzed tandem Enyne Metathesis/hydrovinylation
Chemical communications (Cambridge England), 2010Co-Authors: Jason Gavenonis, Ruben V. Arroyo, Marc L. SnapperAbstract:In situ modification of Grubbs' first-generation Metathesis catalyst allows for a tandem Enyne Metathesis/hydrovinylation that is complementary to the regioselectivity of known ruthenium-catalyzed hydrovinylations.
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Preparation of Alkenyl Cyclopropanes through a Ruthenium-Catalyzed Tandem Enyne Metathesis--Cyclopropanation Sequence
Journal of the American Chemical Society, 2006Co-Authors: Byung Gyu Kim, Marc L. SnapperAbstract:Acyclic Enynes undergo a tandem Enyne Metathesis/cyclopropanation sequence in the presence of Grubbs' 1st generation Metathesis catalyst and diazo compounds. In practice, the acyclic substrates in the presence of the ruthenium alkylidene first undergo a ring-closing Enyne Metathesis to generate cyclic 1,3-dienes; then upon addition of a diazo compound, these products are cyclopropanated selectively at the more accessible olefin. Overall, the reaction sequence converts acyclic Enynes into vinyl cyclopropanes in single operation through two unique ruthenium-catalyzed transformations.
Stevan W Djuric - One of the best experts on this subject based on the ideXlab platform.
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synthesis of fused imidazo azepine derivatives by sequential van leusen Enyne Metathesis reactions
Tetrahedron Letters, 2005Co-Authors: Vijaya Gracias, Alan F Gasiecki, Stevan W DjuricAbstract:A facile synthesis of fused imidazo azepine derivatives by a van Leusen/intramolecular Enyne Metathesis synthetic sequence is reported. The two-step reaction sequence generates compounds of significant molecular complexity from simple starting materials in an expedient fashion with good overall yields.
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Synthesis of fused imidazo azepine derivatives by sequential van Leusen/Enyne Metathesis reactions
Tetrahedron Letters, 2005Co-Authors: Vijaya Gracias, Alan F Gasiecki, Stevan W DjuricAbstract:A facile synthesis of fused imidazo azepine derivatives by a van Leusen/intramolecular Enyne Metathesis synthetic sequence is reported. The two-step reaction sequence generates compounds of significant molecular complexity from simple starting materials in an expedient fashion with good overall yields.
David S. Larsen - One of the best experts on this subject based on the ideXlab platform.
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Synthesis of Acyloxy‐Semicyclic Dienes Using an Enyne Metathesis/Ring Closing Metathesis Approach.
ChemInform, 2015Co-Authors: Jui Thiang Brian Kueh, Lindon W. K. Moodie, Nigel T Lucas, David S. LarsenAbstract:A new approach for the synthesis of semicyclic dienes from Enyne substrates and vinyl esters through an Enyne Metathesis/ring closing Metathesis sequence is developed.
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synthesis of acyloxy semicyclic dienes using an Enyne Metathesis ring closing Metathesis approach
ChemInform, 2015Co-Authors: Jui Thiang Brian Kueh, Lindon W. K. Moodie, Nigel T Lucas, David S. LarsenAbstract:A new approach for the synthesis of semicyclic dienes from Enyne substrates and vinyl esters through an Enyne Metathesis/ring closing Metathesis sequence is developed.
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synthesis of acyloxy semicyclic dienes using an Enyne Metathesis ring closing Metathesis approach
European Journal of Organic Chemistry, 2015Co-Authors: Jui Thiang Brian Kueh, Lindon W. K. Moodie, Nigel T Lucas, David S. LarsenAbstract:An Enyne Metathesis/ring closing Metathesis (EM/RCM) sequence was used to synthesise acyloxy-semicyclic dienes from an Enyne substrate and various vinyl esters. This allowed convenient access to acyloxy-semicyclic dienes not accessible by cross Metathesis alone due to the low reactivity of Fischer carbenes with the termini of 1,3-dienes. This new approach also provides an alternative method for the synthesis of 1-acyloxy-1,3-dienes which are useful reactants for Diels–Alder cycloadditions.
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Synthesis of Acyloxy‐Semicyclic Dienes Using an Enyne Metathesis/Ring Closing Metathesis Approach
European Journal of Organic Chemistry, 2015Co-Authors: Jui Thiang Brian Kueh, Lindon W. K. Moodie, Nigel T Lucas, David S. LarsenAbstract:An Enyne Metathesis/ring closing Metathesis (EM/RCM) sequence was used to synthesise acyloxy-semicyclic dienes from an Enyne substrate and various vinyl esters. This allowed convenient access to acyloxy-semicyclic dienes not accessible by cross Metathesis alone due to the low reactivity of Fischer carbenes with the termini of 1,3-dienes. This new approach also provides an alternative method for the synthesis of 1-acyloxy-1,3-dienes which are useful reactants for Diels–Alder cycloadditions.
Christophe Len - One of the best experts on this subject based on the ideXlab platform.
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Synthesis of 3-vinyl-2,5-dihydrofuran ring system via Enyne Metathesis.
Carbohydrate research, 2009Co-Authors: Sophie Vuong, M. Mercedes Rodriguez‐fernandez, Brigitte Renoux, Christophe LenAbstract:An efficient route, starting from but-3-en-1,2-diol, is described to synthesize racemic diastereoisomeric (5-ethoxy-4-vinyl-2,5-dihydrofuran-2-yl) methanol derivatives. Acyclic Enyne intermediates having the alkyne moiety directly connected to the asymmetric carbon atom of an acetal were obtained in two steps. These reactive substrates were then subjected to ruthenium-catalyzed Enyne Metathesis to produce the target compounds in racemic form. The relative configurations were determined by NOE proton NMR experiments. Similar strategy starting from (2S)-but-3-en-1,2-diol was proposed to provide pure enantiomers.
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3 -Vinyl -2,5 -dihydrofuran derivatives via Enyne Metathesis
Synlett, 2007Co-Authors: M. Mercedes Rodriguez‐fernandez, Sophie Vuong, Brigitte Renoux, Christophe LenAbstract:Acyclic Enynes having the alkyne moiety directly -connected to the asymmetric carbon atom of an acetal were obtained in two steps. These reactive substrates were then subjected to ruthenium-catalyzed Enyne Metathesis to produce (5-ethoxy-4--vinyl-2,5-dihydrofuran-2-yl)methanol derivatives in racemic and enantiomerically pure form. These products are useful glycosyl -donors for the preparation of d4T analogues.