1122-62-9Relevant articles and documents
Highly efficient Au hollow nanosphere catalyzed chemo-selective oxidation of alcohols
Sasidharan, Manickam,Anandhakumar, Sundaramurthy,Bhanja, Piyali,Bhaumik, Asim
, p. 87 - 94 (2016)
Micelles of poly(styrene-b-2-vinyl pyridine-b-ethylene oxide) (PS-PVP-PEO) with core-shell-corona structures have been used as a scaffold for the fabrication of gold (Au) hollow nanospheres of particle size 26 ± 2 nm using HAuCl4 and NaBH4 as metal precursor and reducing agent, respectively. The PS core acts as a template for hollow void, the PVP shell serves as reaction sites for inorganic precursors, and PEO corona stabilizes the composite particles. Under acidic conditions, the PVP shell domain becomes positively charged pyridinum-species that electrostatically interacts with negatively charged AuCl4- ions. On reduction of these composite particles and subsequent solvent extraction leads to the formation of Au hollow nanospheres. Various analytical tools such as powder X-ray diffraction (XRD), transmission electron microscope (TEM), thermogravimetric analyses (TG/DTA), dynamic light scattering of (DLS) have been employed to characterize the polymeric micelles and hollow nanoparticles. The TEM and XRD studies confirmed the formation of highly crystalline Au hollow nanospheres. The Au hollow nanosphere/H2O2 system efficiently catalyzes the chemoselective oxidation of allylic-type unsaturated alcohols into aldehydes and ketones under mild liquid-phase conditions. The versatility of present catalytic system for the oxidation of other substrates like aliphatic-, acylic-, aromatic-, and heteroaromatic alcohols to their respective keto compounds has also been reported.
Kinetic Resolution of 1-Aryl- and 1-Heteroaryl Ethanols by Oxidation with Baker's Yeast
Fantin, Giancarlo,Fogagnolo, Marco,Medici, Alessandro,Pedrini, Paola,Poli, Silvia,Sinigaglia, Milena
, p. 883 - 884 (1993)
The kinetic resolution of racemic 1-aryl and 1-heteroaryl ethanols 1a-e via oxidation by Baker's yeast to give the R-enantiomer is reported.Key Words: Kinetic resolution, Oxidation, Baker's yeast, 1-Aryl ethanol, 1-Heteroaryl ethanol
Highly efficient dehydrogenation of secondary alcohols catalyzed by iridium-CNP complexes
Wang, Dawei,Zhao, Keyan,Yang, Shuyan,Ding, Yuqiang
, p. 2016 - 2020 (2014)
A new highly practical method is presented for dehydrogenation of secondary alcohols to the corresponding ketones catalyzed by the iridium-CNP complexes. The reactions are compatible with substrates bearing diverse functional groups and proceed efficiently under mild conditions.
Aerobic oxidation of alcohols at room temperature and atmospheric conditions catalyzed by reusable gold nanoclusters stabilized by the benzene rings of polystyrene derivatives
Miyamura, Hiroyuki,Matsubara, Ryosuke,Miyazaki, Yoji,Kobayashi, Shu
, p. 4151 - 4154 (2007)
(Chemical Equation Presented) Lock up your gold: Polymer-incarcerated gold nanoclusters (PI Au) were synthesized by microencapsulation of gold nanoclusters and cross-linking using a copolymer based on polystyrene (see TEM image). The nanoclusters could be used to catalyze the aerobic oxidation of alcohols to aldehydes and ketones under atmospheric conditions at room temperature, and additionally could be reused with little loss of activity.
Modular O-: Vs. N-coordination of pyridylidene amide ligands to iron determines activity in alcohol oxidation catalysis
Verhoeven, Dide G. A.,Albrecht, Martin
, p. 17674 - 17682 (2020)
A family of polydentate pyridine-substituted pyridylidene amide (PYA) complexes bound to iron(ii) was developed. The variation of the coordination set from NN-bidentate PYA to tridentate pincer-type pyPYA2 systems (pyPYA2 = 2,6-bis(PYA)pyridine) had a large influence on the binding mode to iron(ii), including a change from the N- to rare O-coordination of the PYA site and a concomitant shift of the predominant ligand resonance structure. These binding mode variations invoke changes in the reactivity of the complexes, which were probed in the peroxide-mediated oxidation of 1-phenylethanol to acetophenone. A comparison with uncomplexed FeCl2 indicated that bidentate NN coordination is unstable and presumably leads to the dissociation of FeCl2. In contrast, the tridentate ligand binding is robust. Remarkably, the tridentate PYA pincer coordination inhibits catalytic activity in the NNN binding mode, while the ONO coordination greatly enhances catalytic performance. Under optimized conditions, the bis-ligated ONO pincer iron complex [Fe(pyPYA2)2][2PF6] reaches full conversion within one hour (0.5 mol% catalyst loading) and under dilute conditions turnover numbers over 20?000 (0.005 mol% catalyst loading). This journal is
Acylation of Grignard reagents mediated by N-methylpyrrolidone: A remarkable selectivity for the synthesis of ketones
Gowda, Maravanhalli Sidde,Pande, Sushanth Sudhir,Ramakrishna, Ramesha Andagar,Prabhu, Kandikere Ramaiah
, p. 5365 - 5368 (2011)
An efficient user-friendly method of acylation of Grignard reagents to selectively synthesize ketones is presented, which is assisted by simple amides such as NMP, or DMF. The present chemoselective method tolerates a variety of functional groups such as ketone, ester, nitrile and other functional groups.
Studies on pyrazines; 38: Acylation of bromopyrazines and 2-bromopyridine via copper-cocatalytic stille reaction
Sato,Narita
, p. 1551 - 1555 (2001)
Synthesis of acetylpyrazines 3 and propionylpyrazines 5 was achieved by copper-cocatalytic Stille reaction of bromopyrazines 1 with tributyl(1-ethoxyalkenyl)tin and then acidic hydrolysis. The optimal reaction conditions involve the combination of 15 molp
New Organocatalyst scaffolds with high activity in promoting hydrazone and oxime formation at neutral pH
Larsen, Dennis,Pittelkow, Michael,Karmakar, Saswata,Kool, Eric T.
, p. 274 - 277 (2015)
The discovery of two new classes of catalysts for hydrazone and oxime formation in water at neutral pH, namely 2-aminophenols and 2-(aminomethyl)benzimidazoles, is reported. Kinetics studies in aqueous solutions at pH 7.4 revealed rate enhancements up to 7-fold greater than with classic aniline catalysis. 2-(Aminomethyl)benzimidazoles were found to be effective catalysts with otherwise challenging aryl ketone substrates.
Methoxy(2-pyridyl)ketene
Andersen, Heidi Gade,Bednarek, Pawel,Wentrup, Curt
, p. 519 - 524 (2003)
The matrix photolysis of 3-methoxy-carbonyl-1,2,3-triazolopyridine was reported to yield methoxy(2-pyridyl)ketene. Photolysis of the triazolopyridines was found to be a less efficient method of producing the 2-pyridyl-ketenes. The results showed that a different ketene was formed by photolysis, but flash vacuum thermolysis (FVT) afforded the desired methoxy(2-pyridyl)ketene.
Gold-platinum bimetallic clusters for aerobic oxidation of alcohols under ambient conditions
Miyamura, Hiroyuki,Matsubara, Ryosuke,Kobayashi, Shu
, p. 2031 - 2033 (2008)
We have developed gold/platinum alloyed bimetallic cluster catalysts supported on a cross-linked polystyrene derivative, which present much higher activity and selectivity than single metal gold or platinum clusters for aerobic oxidation of alcohols under ambient conditions. The Royal Society of Chemistry.
