ADVERTISEMENT RETURN TO ISSUECommunicationNEXTAn Azophenol-based Chromogenic Pyrophosphate Sensor in WaterDong Hoon Lee, Ja Hyun Im, Seung Uk Son, Young Keun Chung, and Jong-In HongView Author Information Department of Chemistry, College Natural Sciences, Seoul National University, 151-747, Korea, Center for Molecular Design Synthesis, KAIST, Daejon 305-701, Korea Cite this: J. Am. Chem. Soc. 2003, 125, 26, 7752–7753Publication Date (Web):June 6, 2003Publication History Received17 February...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPromoters for the (alkyne) hexacarbonyldicobalt-based cyclopentenone synthesisYoung Keun Chung, Bun Yeoul Lee, Nakcheol Jeong, Milan Hudecek, and Peter L. PausonCite this: Organometallics 1993, 12, 1, 220–223Publication Date (Print):January 1993Publication History Published online1 May 2002Published inissue 1 January 1993https://pubs.acs.org/doi/10.1021/om00025a036https://doi.org/10.1021/om00025a036research-articleACS PublicationsRequest reuse...

Novel complexes 1 and 2 based on N-heterocyclic carbenes, which are analogous to Ru(bpy)(3)(2+) Ru(terpy)(2)(2+), respectively, were synthesized. The complex, is exhibited promising photoluminescence properties with a long lifetime of 820 ns in acetonitrile 3100 water at room temperature, respectively. In addition, ab initio calculations carried out.

Various iridium complexes consisting of phenylpyrazole (ppz) ligands and isoquinolinecarboxylic acids (iq) as ancillary were designed by energy band-gap calculations via ab initio synthesized to give rise various emission wavelengths expected. Fine color tuning was achieved through varying the position methyl substituent on moiety with HOMO electron densities. Additional made possible altering LUMO use different such 1-isoquinolinecarboxylic acid (1iq) 3-isoquinolinecarboxylic (3iq).

We synthesize quinoxalines, catalyzed by manganese(IV) dioxide, from a variety of α-hydroxyketones followed trapping with aromatic or aliphatic 1,2-diamines without using solvent, within one minute under microwave irradiation.

Three ruthenium(II) complexes with N-heterocyclic carbene (NHC) or NHC/2,2′:6′,2′′-terpyridine (tpy) hybrid ligands, bis[2,6-bis(3-methylimidazol-3-ium-1-yl)pyridine-4-carboxylic acid]ruthenium(II) (BCN), [2,6-bis(3-methylimidazolium-1-yl)pyridine-4-carboxylic acid](2,2′;6′2′′-terpyridine)ruthenium(II) (TCN), and [2,6-bis(3-methylimidazol-3-ium-1-yl)pyridine](2,2′;6′2′′-terpyridine-4′-carboxylic acid)ruthenium(II) (CTN), have been synthesized characterized by 1H 13C NMR, high-resolution mass...

Abstract This communication describes a ruthenium nanoparticle‐catalyzed reduction of nitroarenes giving azoxyarenes, azoarenes, or anilines in good to excellent yields using ethanol as hydrogen source.

Cobalt–rhodium heterobimetallic nanoparticle-catalyzed reductive amination of aldehydes and ketones with amines in the presence 5 atm carbon monoxide without an external hydrogen source has been developed. Water added generated situ produces via a water–gas-shift reaction. The reaction can be extended to tandem reduction nitroarenes. catalytic system is stable under conditions could reused eight times losing any activity.

The assembly of Co(NCS)(2) with 1-methyl-1'-(3-pyridyl)-2-(4-pyridyl)ethene (L(1)) exhibits a novel supramolecular isomerism [Co(L(1))(2)(NCS)(2)](infinity) caused by different placement orientation L(1) around metal centers. reaction in MeOH/H(2)O and EtOH/H(2)O resulted double chain structure 1, that EtOH/CH(3)NO(2) led to an open framework 2. MeOH/CH(3)NO(2) solvent system concomitantly afforded 1 assemblies 1-(3-pyridyl)-2-(4-pyrimidyl)ethene (L(2)) created the water-coordinated...

ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTCobalt on Mesoporous Silica: The First Heterogeneous Pauson−Khand CatalystSang-Wook Kim, Seung Uk Son, Sang Ick Lee, Taeghwan Hyeon, and Young Keun ChungView Author Information Department of Chemistry Center for Molecular Catalysis School Chemical Engineering Institute Processes Seoul National University, 151-742, Korea Cite this: J. Am. Chem. Soc. 2000, 122, 7, 1550–1551Publication Date (Web):February 2, 2000Publication History Received8...

Assemblies of 1-methyl-1',2-bis(4-pyridyl)ethene (mpe) and Co(NCS)(2) afford three isomeric framework networks different topological features depending on the assembly conditions. Isomerism control solid-to-solid transformation phenomena are observed among them.

The first water-soluble asymmetric hydrogen-transfer ruthenium(II) catalyst system consisting of [Ru(p-cymene)Cl2]2, (S)-proline amide, and sodium formate, which gives high conversion rates with ee values up to 95.3% is reusable, has been developed.

Chiral ferrocenyl imidazolium salts were obtained from optically pure alcohols or acetates by substitution with retention of configurations. Their rhodium and iridium complexes synthesized applied to asymmetric hydrogenations. The benzimidazolylidene−iridium complex showed up 52.6% ee in the transfer hydrogenation 4'-methylacetophenone.

A rhodium complex of N-heterocyclic carbene (NHC) has been developed for intra- and intermolecular [4 + 2] intramolecular [5 cycloaddition reactions. This is the first use a transition-metal NHC in Diels−Alder-type reaction. For reactions, all dienynes studied were converted to their corresponding cycloadducts 91−99% yields within 10 min. Moreover, up 1900 turnovers have obtained at 15− 20 °C. cycloadditions, high (71−99%) products obtained. The reaction time yield highly dependent upon...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAddition of Grignard reagents and ketone enolates to the arene in (arene)manganese tricarbonyl cationsYoung Keun Chung, Paul G. Williard, Dwight A. SweigartCite this: Organometallics 1982, 1, 8, 1053–1056Publication Date (Print):August 1982Publication History Published online1 May 2002Published inissue 1 August 1982https://pubs.acs.org/doi/10.1021/om00068a009https://doi.org/10.1021/om00068a009research-articleACS PublicationsRequest reuse...

A silver(I)-catalyzed facile formation of pyrazoles from propargyl N-sulfonylhydrazones has been disclosed. During the reaction, a migration sulfonyl groups (Ts, Ms) was observed. Good functional group compatibility observed under mild reaction conditions (at room temperature for 3−5 h). This methodology allows efficient and regioselective synthesis 1,3- 1,5-disubstituted 1,3,5-trisubstituted pyrazoles.

Abstract Poly(3,4‐dimethyl‐5‐vinylthiazolium) was synthesized from 3,4‐dimethyl‐5‐vinylthiazole through free radical polymerization and examined as polymer precatalysts in the presence of 1,8‐diazabicyclo[5.4.0]undec‐7‐ene (DBU) for thioesterification aldehydes with thiols. The poly(5‐vinylthiazolium)/DBU had excellent catalytic activity could be reused 10 times without a considerable loss activity.

A cobalt–rhodium heterobimetallic nanoparticle-catalyzed reductive cyclization of 2-(2-nitroaryl)acetonitriles to indoles has been achieved. The tandem reaction proceeds without any additives under the mild conditions (1 atm H2 and 25 °C). This procedure could be scaled up gram scale. catalytic system is significantly stable these reused more than ten times loss activity.

Reaction of Co(NCS)2 with 1-methyl-1'-(4-pyridyl)-2-(4-pyrimidyl)ethylene (mppe) in different solvents yields two kinds novel coordination polymer structures [Co(mppe)2(NCS)2]n: one them shows an unprecedented interpenetrating structure both 2D and 3D topological isomers.

The self-assembly of metallosupramolecules from reactions flexible 2-pyridyl ligands and silver salts is described. When 1,3-bis(2-pyridyl)propane (L1), tris[(2-pyridyl)methyl]methane (L2), 1,3-bis(2-pyridyl)-2-tolylpropane (L3) are used in combination with ions, novel discrete metallocyclic complexes formed crystals. Moreover, the 1,3-bis(2-pyridyl)-2-phenylpropane (L4) nitrate yields a coordination polymer. examination its solution shows that this polymer via solution-based species.

ADVERTISEMENT RETURN TO ISSUEPREVLetterNEXTCobalt−Rhodium Heterobimetallic Nanoparticle-Catalyzed Synthesis of α,β-Unsaturated Amides from Internal Alkynes, Amines, and Carbon MonoxideJi Hoon Park, Sun Young Kim, Soo Min Keun ChungView Author Information Intelligent Textile System Research Center, Department Chemistry, College Natural Sciences, Seoul National University, 151-747, Korea Cite this: Org. Lett. 2007, 9, 13, 2465–2468Publication Date (Web):May 23, 2007Publication History...