The Experts below are selected from a list of 2019 Experts worldwide ranked by ideXlab platform
Antoni Riera - One of the best experts on this subject based on the ideXlab platform.
-
Ethylene Glycol Assisted Intermolecular Pauson–Khand Reaction
Synthesis, 2017Co-Authors: Albert Cabré, Xavier Verdaguer, Antoni RieraAbstract:The use of ethylene glycol as additive in the N-oxide-promoted intermolecular Pauson–Khand Reaction (PKR) has been studied. The addition of 15% ethylene glycol to the Reaction mixture consistently increased (from 20% up to 2–4-fold) the Reaction yields.
-
ethylene glycol assisted intermolecular Pauson Khand Reaction
Synthesis, 2017Co-Authors: Albert Cabré, Xavier Verdaguer, Antoni RieraAbstract:The use of ethylene glycol as additive in the N-oxide-promoted intermolecular Pauson–Khand Reaction (PKR) has been studied. The addition of 15% ethylene glycol to the Reaction mixture consistently increased (from 20% up to 2–4-fold) the Reaction yields.
-
asymmetric intermolecular cobalt catalyzed Pauson Khand Reaction using a p stereogenic bis phosphane
ChemInform, 2015Co-Authors: Sílvia Orgué, Antoni Riera, Thierry León, Xavier VerdaguerAbstract:A novel family of P-stereogenic diphosphane ligands is developed and applied in the asymmetric cobalt-catalyzed Pauson—Khand Reaction.
-
Asymmetric Intermolecular Cobalt-Catalyzed Pauson—Khand Reaction Using a P-Stereogenic Bis-phosphane.
ChemInform, 2015Co-Authors: Sílvia Orgué, Antoni Riera, Thierry León, Xavier VerdaguerAbstract:A novel family of P-stereogenic diphosphane ligands is developed and applied in the asymmetric cobalt-catalyzed Pauson—Khand Reaction.
-
asymmetric intermolecular cobalt catalyzed Pauson Khand Reaction using a p stereogenic bis phosphane
Organic Letters, 2015Co-Authors: Sílvia Orgué, Antoni Riera, Thierry León, Xavier VerdaguerAbstract:The asymmetric intermolecular and catalytic Pauson–Khand Reaction has remained an elusive goal since Khand and Pauson discovered this transformation. Using a novel family of P-stereogenic phosphanes, we developed the first catalytic system with useful levels of enantioselection for the Reaction of norbornadiene and trimethylsilylacetylene. The results demonstrate that Co–bisphosphane systems are sufficiently reactive and that they lead to high selectivity in the intermolecular process.
Xavier Verdaguer - One of the best experts on this subject based on the ideXlab platform.
-
Ethylene Glycol Assisted Intermolecular Pauson–Khand Reaction
Synthesis, 2017Co-Authors: Albert Cabré, Xavier Verdaguer, Antoni RieraAbstract:The use of ethylene glycol as additive in the N-oxide-promoted intermolecular Pauson–Khand Reaction (PKR) has been studied. The addition of 15% ethylene glycol to the Reaction mixture consistently increased (from 20% up to 2–4-fold) the Reaction yields.
-
ethylene glycol assisted intermolecular Pauson Khand Reaction
Synthesis, 2017Co-Authors: Albert Cabré, Xavier Verdaguer, Antoni RieraAbstract:The use of ethylene glycol as additive in the N-oxide-promoted intermolecular Pauson–Khand Reaction (PKR) has been studied. The addition of 15% ethylene glycol to the Reaction mixture consistently increased (from 20% up to 2–4-fold) the Reaction yields.
-
asymmetric intermolecular cobalt catalyzed Pauson Khand Reaction using a p stereogenic bis phosphane
ChemInform, 2015Co-Authors: Sílvia Orgué, Antoni Riera, Thierry León, Xavier VerdaguerAbstract:A novel family of P-stereogenic diphosphane ligands is developed and applied in the asymmetric cobalt-catalyzed Pauson—Khand Reaction.
-
Asymmetric Intermolecular Cobalt-Catalyzed Pauson—Khand Reaction Using a P-Stereogenic Bis-phosphane.
ChemInform, 2015Co-Authors: Sílvia Orgué, Antoni Riera, Thierry León, Xavier VerdaguerAbstract:A novel family of P-stereogenic diphosphane ligands is developed and applied in the asymmetric cobalt-catalyzed Pauson—Khand Reaction.
-
asymmetric intermolecular cobalt catalyzed Pauson Khand Reaction using a p stereogenic bis phosphane
Organic Letters, 2015Co-Authors: Sílvia Orgué, Antoni Riera, Thierry León, Xavier VerdaguerAbstract:The asymmetric intermolecular and catalytic Pauson–Khand Reaction has remained an elusive goal since Khand and Pauson discovered this transformation. Using a novel family of P-stereogenic phosphanes, we developed the first catalytic system with useful levels of enantioselection for the Reaction of norbornadiene and trimethylsilylacetylene. The results demonstrate that Co–bisphosphane systems are sufficiently reactive and that they lead to high selectivity in the intermolecular process.
Zhen Yang - One of the best experts on this subject based on the ideXlab platform.
-
Evolution of Pauson-Khand Reaction: Strategic Applications in Total Syntheses of Architecturally Complex Natural Products (2016–2020)
Catalysts, 2020Co-Authors: Sijia Chen, Zhen Yang, Chongguo Jiang, Nan Zheng, Lili ShiAbstract:Metal-mediated cyclizations are important transformations in a natural product total synthesis. The Pauson-Khand Reaction, particularly powerful for establishing cyclopentenone-containing structures, is distinguished as one of the most attractive annulation processes routinely employed in synthesis campaigns. This review covers Co, Rh, and Pd catalyzed Pauson-Khand Reaction and summarizes its strategic applications in total syntheses of structurally complex natural products in the last five years. Additionally, the hetero-Pauson-Khand Reaction in the synthesis of heterocycles will also be discussed. Focusing on the panorama of organic synthesis, this review highlights the strategically developed Pauson-Khand Reaction in fulfilling total synthetic tasks and its synthetic attractiveness is aimed to be illustrated.
-
asymmetric total synthesis of fusarisetin a via the intramolecular Pauson Khand Reaction
Organic Letters, 2013Co-Authors: Jun Huang, Lili Shi, Lichao Fang, Rong Long, Hongjuan Shen, Zhen YangAbstract:An asymmetic total synthesis of (+)-fusarisetin A has been achieved. The essential to our strategy was the application of the intramolecular Pauson–Khand Reaction for the stereoselective construction of the trans-decalin subunit of (+)-fusarisetin A with a unique C16 quarternary chiral center. The developed chemistry offers an alternative to the IMDA Reaction that has been used for fusarisetin A, and is applicable to analogue synthesis for biological evaluation.
-
CoBr2—TMTU—Zinc-Catalyzed Pauson—Khand Reaction.
ChemInform, 2012Co-Authors: Yuefan Wang, Jiahua Chen, Zhen YangAbstract:Th complex is generated generated in situ by reduction of CoBr2 with Zn and efficiently promotes the Pauson—Khand Reaction affording structurally diverse cyclopentenones (20 examples).
-
cobr2 tmtu zinc catalysed Pauson Khand Reaction
Chemical Communications, 2012Co-Authors: Yuefan Wang, Jiahua Chen, Zhen YangAbstract:A cobalt–TMTU complex, derived from the in situ reduction of CoBr2 with Zn in the presence of TMTU, can catalyze Pauson–Khand Reaction at a balloon pressure of CO, which enables the synthesis of structurally diverse cyclopentenones. This catalytic system works efficiently for both intermolecular and intramolecular PK Reactions.
-
CoBr2–TMTU–zinc catalysed-Pauson–Khand Reaction
Chemical communications (Cambridge England), 2012Co-Authors: Yuefan Wang, Jiahua Chen, Zhen YangAbstract:A cobalt–TMTU complex, derived from the in situ reduction of CoBr2 with Zn in the presence of TMTU, can catalyze Pauson–Khand Reaction at a balloon pressure of CO, which enables the synthesis of structurally diverse cyclopentenones. This catalytic system works efficiently for both intermolecular and intramolecular PK Reactions.
Agustí Lledó - One of the best experts on this subject based on the ideXlab platform.
-
The Pauson–Khand Reaction of medium sized trans-cycloalkenes
Chemical communications (Cambridge England), 2013Co-Authors: Agustí Lledó, Xavier Verdaguer, Marc Revés, Aida Fuster, Antoni RieraAbstract:Medium sized trans-cycloalkenes are unusually reactive in the intermolecular Pauson–Khand Reaction (PKR) with regard to typical monocyclic alkenes. This is due to the ring strain imparted by the E stereochemistry. The PKR of these alkenes offers a modular, regioselective and straightforward entry to trans fused [n.3.0] bicyclic scaffolds (n = 6–8).
-
the Pauson Khand Reaction of medium sized trans cycloalkenes
Chemical Communications, 2013Co-Authors: Agustí Lledó, Xavier Verdaguer, Marc Revés, Aida Fuster, Antoni RieraAbstract:Medium sized trans-cycloalkenes are unusually reactive in the intermolecular Pauson–Khand Reaction (PKR) with regard to typical monocyclic alkenes. This is due to the ring strain imparted by the E stereochemistry. The PKR of these alkenes offers a modular, regioselective and straightforward entry to trans fused [n.3.0] bicyclic scaffolds (n = 6–8).
-
PuPHOS and CamPHOS Ligands in the Intermolecular Catalytic Pauson–Khand Reaction
Advanced Synthesis & Catalysis, 2007Co-Authors: Agustí Lledó, Antoni Riera, Xavier Verdaguer, Jordi Solà, Miguel A. MaestroAbstract:The first asymmetric intermolecular cobalt-catalyzed Pauson–Khand Reaction is described. The use of the hemilabile CamPHOS ligand provides good conversions and selectivity up to 28 % ee. The catalytic process was studied by in situ FT-IR and it was found that both bridged and non-bridged complexes were present in the Reaction mixture. Our results suggest that recognition between the alkyne substrate and the ligand is essential to attain stereocontrol in the catalytic cyclization.
-
Kinetic Studies on the Cobalt-Catalyzed Norbornadiene Intermolecular Pauson−Khand Reaction
Organometallics, 2007Co-Authors: Rafel Cabot, Agustí Lledó, Marc Revés, A. Riera, Xavier VerdaguerAbstract:The kinetics for the cobalt-catalyzed intermolecular Pauson−Khand Reaction (PKR) between (trimethylsilyl)acetylene and norbornadiene (NBD) at a constant CO pressure has been studied by means of in ...
Young Keun Chung - One of the best experts on this subject based on the ideXlab platform.
-
Allenic Pauson-Khand Reaction Catalyzed by Cobalt-Rhodium Heterobimetallic Nanoparticles
Synlett, 2007Co-Authors: Jihoon Park, Sang Ick Lee, Sun Young Kim, Soo Min Kim, Young Keun ChungAbstract:Pauson-Khand Reaction of allenynes, catalyzed by Co-Rh heterobimetallic nanoparticles, was developed for the synthesis of [5.6]- and [5.7]-bicyclic enones. The cyclization occurred selectively with the distal double bond of the allene. The catalytic system could be used at least six times without loss of catalytic activity.
-
Tandem Pauson-Khand Reaction and Diels-Alder Reaction for access to polycycles in a one-pot Reaction.
Chemical communications (Cambridge England), 2005Co-Authors: Han Kim, Young Keun ChungAbstract:Starting from easily available cyclic alkenes, enynes, and dienophiles, a tandem intermolecular Pauson-Khand Reaction and Diels-Alder Reaction yields polycyclic compounds in high yields.
-
Rh(I)-Catalyzed Asymmetric Intramolecular Pauson-Khand Reaction in Aqueous Media
Synthesis, 2003Co-Authors: Won Hyuck Suh, Mira Choi, Sang Ick Lee, Young Keun ChungAbstract:The first rhodium-BINAP complex-catalyzed enantioselective Pauson-Khand Reaction in aqueous media, which is accelerated by surfactant, is reported. The chiral rhodium catalyst is easily prepared in situ from I equivalent of [Rh(cod)Cl] 2 and 2 equivalents of BINAP under I atm of CO and a temperature of 60 °C or 90 °C. Ee's up to 96% were achieved for the intramolecular Pauson-Khand Reaction, but the yields are highly dependent upon the substrate itself.
-
Cobalt nanoparticles on charcoal: a versatile catalyst in the Pauson-Khand Reaction, hydrogenation, and the reductive Pauson-Khand Reaction.
Organic letters, 2002Co-Authors: Seung Uk Son, Kang Hyun Park, Young Keun ChungAbstract:Dispersions of nanometer-sized cobalt particles with very high stability were prepared in charcoal and analyzed by electron microscopy and X-ray analysis. The resulting cobalt nanoparticles on charcoal (CNC) were successfully used as a catalyst for the carbonylative cycloaddition of alkyne, alkene, and carbon monoxide (Pauson−Khand Reaction), hydrogenation, and the reductive Pauson−Khand Reaction.
-
The first intramolecular Pauson-Khand Reaction in water using aqueous colloidal cobalt nanoparticles as catalysts.
Organic letters, 2002Co-Authors: Seung Uk Son, Young Keun Chung, Sang Ick Lee, Sang-wook Kim, Taeghwan HyeonAbstract:The first intramolecular Pauson−Khand Reaction in water was successfully carried out by using aqueous colloidal cobalt nanoparticles as catalysts.