The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Yoonsik Lee - One of the best experts on this subject based on the ideXlab platform.
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copper free sonogashira cross coupling reaction catalyzed by polymer supported n heterocyclic carbene Palladium Complex
Tetrahedron Letters, 2007Co-Authors: Jongho Kim, Dongho Lee, Bonghyun Jun, Yoonsik LeeAbstract:Abstract A core-shell type of polymer-supported N -heterocyclic carbene (NHC) Palladium catalyst was applied to Sonogashira cross-coupling reactions without copper cocatalyst under ambient atmosphere. This supported NHC–Palladium Complex efficiently catalyzed the copper-free Sonogashira reaction of various aryl iodides and bromides with terminal alkynes; the reaction exhibited high dependency on the temperature and the amount of base as well as its nature. In addition, this heterogeneous catalyst exhibited good reusability for the copper-free Sonogashira reaction.
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polymer supported n heterocyclic carbene Palladium Complex for heterogeneous suzuki cross coupling reaction
Journal of Organic Chemistry, 2005Co-Authors: Jongho Kim, Mohammadreza Shokouhimehr, Jungwoo Kim, Yoonsik LeeAbstract:Poly(1-methylimidazoliummethyl styrene)-surface grafted-poly(styrene) resin was prepared for the first time as a polymer-supported N-heterocyclic carbene (NHC) precursor for Palladium Complex by suspension polymerization. To prepare this polymer-supported NHC precursor, 1-methyl-3-(4-vinylbenzyl)imidazolium hexafluorophosphate, [MVBIM][PF6-], was synthesized as a monomer and copolymerized with styrene and DVB in water. This polymer-supported NHC precursor with imidazolium as a ligand, which exists solely on the surface of the resin, was well characterized by FE-SEM, CLSM, and IR spectroscopy. The precursor containing imidazolium readily formed a stable Complex with Pd(OAc)2, and this polymer-supported N-heterocyclic carbene-Palladium Complex exhibited excellent catalytic activity for Suzuki cross-coupling reaction in an aqueous medium. The catalyst was recovered quantitatively from the reaction mixture by simple filtration and was able to be reused for a number of recycles with consistent activity in all of the coupling reactions.
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n heterocyclic carbene Palladium Complex on polystyrene resin surface as polymer supported catalyst and its application in suzuki cross coupling reaction
Tetrahedron Letters, 2004Co-Authors: Jongho Kim, Bonghyun Jun, Jangwoong Byun, Yoonsik LeeAbstract:A poly(imidazoliummethyl styrene)-surface grafted-polystyrene resin was prepared by suspension polymerization. This was used as the polymer-supported carbene precursor for the Palladium Complex, which efficiently catalyzed the Suzuki cross-coupling of aryl halides and phenylboronic acid.
Jongho Kim - One of the best experts on this subject based on the ideXlab platform.
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copper free sonogashira cross coupling reaction catalyzed by polymer supported n heterocyclic carbene Palladium Complex
Tetrahedron Letters, 2007Co-Authors: Jongho Kim, Dongho Lee, Bonghyun Jun, Yoonsik LeeAbstract:Abstract A core-shell type of polymer-supported N -heterocyclic carbene (NHC) Palladium catalyst was applied to Sonogashira cross-coupling reactions without copper cocatalyst under ambient atmosphere. This supported NHC–Palladium Complex efficiently catalyzed the copper-free Sonogashira reaction of various aryl iodides and bromides with terminal alkynes; the reaction exhibited high dependency on the temperature and the amount of base as well as its nature. In addition, this heterogeneous catalyst exhibited good reusability for the copper-free Sonogashira reaction.
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polymer supported n heterocyclic carbene Palladium Complex for heterogeneous suzuki cross coupling reaction
Journal of Organic Chemistry, 2005Co-Authors: Jongho Kim, Mohammadreza Shokouhimehr, Jungwoo Kim, Yoonsik LeeAbstract:Poly(1-methylimidazoliummethyl styrene)-surface grafted-poly(styrene) resin was prepared for the first time as a polymer-supported N-heterocyclic carbene (NHC) precursor for Palladium Complex by suspension polymerization. To prepare this polymer-supported NHC precursor, 1-methyl-3-(4-vinylbenzyl)imidazolium hexafluorophosphate, [MVBIM][PF6-], was synthesized as a monomer and copolymerized with styrene and DVB in water. This polymer-supported NHC precursor with imidazolium as a ligand, which exists solely on the surface of the resin, was well characterized by FE-SEM, CLSM, and IR spectroscopy. The precursor containing imidazolium readily formed a stable Complex with Pd(OAc)2, and this polymer-supported N-heterocyclic carbene-Palladium Complex exhibited excellent catalytic activity for Suzuki cross-coupling reaction in an aqueous medium. The catalyst was recovered quantitatively from the reaction mixture by simple filtration and was able to be reused for a number of recycles with consistent activity in all of the coupling reactions.
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n heterocyclic carbene Palladium Complex on polystyrene resin surface as polymer supported catalyst and its application in suzuki cross coupling reaction
Tetrahedron Letters, 2004Co-Authors: Jongho Kim, Bonghyun Jun, Jangwoong Byun, Yoonsik LeeAbstract:A poly(imidazoliummethyl styrene)-surface grafted-polystyrene resin was prepared by suspension polymerization. This was used as the polymer-supported carbene precursor for the Palladium Complex, which efficiently catalyzed the Suzuki cross-coupling of aryl halides and phenylboronic acid.
Hanmin Huang - One of the best experts on this subject based on the ideXlab platform.
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enantioselective aminomethylamination of conjugated dienes with aminals enabled by chiral Palladium Complex catalyzed c n bond activation
Journal of the American Chemical Society, 2016Co-Authors: Yang Liu, Yinjun Xie, Hongli Wang, Hanmin HuangAbstract:A novel highly enantioselective aminomethylamination of conjugated dienes with aminals catalyzed by a chiral Palladium Complex ligated with BINOL-derived chiral diphosphinite has been successfully developed. This reaction proceeds via a Pd-catalyzed cascade C–N bond activation, aminomethylation, and asymmetric allylic amination reaction under mild reaction conditions, providing a unique and efficient strategy for the synthesis of enantiomerically pure allylic 1,3-diamines.
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Palladium catalyzed direct amination of allylic alcohols at room temperature
ChemInform, 2015Co-Authors: Maorong Wang, Yinjun Xie, Hanmin HuangAbstract:A Palladium Complex efficiently allows the direct amination of allylic alcohols with amines at room temperature without further additives.
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Palladium catalyzed direct amination of allylic alcohols at room temperature
Synlett, 2014Co-Authors: Maorong Wang, Yinjun Xie, Hanmin HuangAbstract:A Palladium Complex ligated with Xantphos has been identified as an efficient catalyst for the catalytic amination of allylic alcohols, which allows the direct amination of allylic alcohols with amines to proceed at room temperature in the absence of additives. The method is compatible with a variety of functional groups and can be used to prepare a wide range of linear allylic amines in good to excellent yields with high stereoselectivities.
David M Perrin - One of the best experts on this subject based on the ideXlab platform.
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c sp2 c sp2 cross coupling reaction catalyzed by a water stable Palladium Complex supported onto nanomagnetite particles
ChemInform, 2015Co-Authors: Tahereh Azadbakht, Mohammad Ali Zolfigol, Reza Azadbakht, Vahid Khakyzadeh, David M PerrinAbstract:Diaryl compounds (III) are efficiently, simply, and cost-effectively synthesized by Suzuki reaction using a Palladium Complex supported onto magnetite nanoparticles as easily recyclable and stable catalyst.
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c sp2 c sp2 cross coupling reaction catalyzed by a water stable Palladium Complex supported onto nanomagnetite particles
New Journal of Chemistry, 2015Co-Authors: Tahereh Azadbakht, Mohammad Ali Zolfigol, Reza Azadbakht, Vahid Khakyzadeh, David M PerrinAbstract:A water-stable Palladium Complex supported onto nanomagnetite particles was prepared and characterized. The nanocatalyst showed excellent reusability and activity in aqueous phase processes including the C(sp2)–C(sp2) cross coupling reactions. The advantages of the protocol are its generality, high yields, short reaction time, a cleaner reaction profile, and simplicity.
Chun Cai - One of the best experts on this subject based on the ideXlab platform.
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polymer supported macrocyclic schiff base Palladium Complex as an efficient catalyst for the heck reaction
Applied Organometallic Chemistry, 2011Co-Authors: Chun CaiAbstract:A polymer-supported macrocyclic Schiff base Palladium Complex has been synthesized. In the Heck reaction of aryl iodides and bromides with ethyl acrylate or styrene, the Complex has been proved to give the corresponding products in good to excellent yields. The reaction proceeded smoothly in the presence of 0.5 mol% of catalyst in DMF within 1–4 h. Recycling studies have shown that the catalyst can be readily recovered and reused for four cycles with only a slightly decrease in its activity. Copyright © 2011 John Wiley & Sons, Ltd.
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polymer supported macrocyclic schiff base Palladium Complex an efficient and reusable catalyst for suzuki cross coupling reaction under ambient condition
Catalysis Communications, 2011Co-Authors: Chun CaiAbstract:Abstract Polymer-supported macrocyclic Schiff base Palladium Complex was prepared and characterized. The catalyst exhibits excellent catalytic activity and stability for Suzuki cross-coupling reaction under ambient condition. Various aryl bromides were coupled with aryl boronic acids in DMF/H 2 O, under air, in the presence of 0.1 mol% of the catalyst to afford corresponding cross-coupled products in high yields within 20–30 min. Furthermore, the heterogeneous catalyst can be readily recovered by simple filtration and reused several times without significant loss in its activity.