21811-48-3Relevant academic research and scientific papers
Oxidation of Tertiary Aromatic Alcohols to Ketones in Water
Chen, Dengfeng,Zhang, Yuchen,Pan, Xingyu,Wang, Fei,Huang, Shenlin
, p. 3607 - 3612 (2018)
A new rosin-based amphiphile enables the oxidation of tertiary aromatic alcohols in water under mild conditions. The oxidation process is mediated by β-scission of alkoxy radicals. Our catalyst system including the surfactant, catalysts, and water can be easily recycled within the same reaction vial. (Figure presented.).
ASYMMETRIC SYNTHESIS BY CHIRAL RUTHENIUM COMPLEXES. IX. THE ROLE OF ISOMERIZATION IN THE ASYMMETRIC HYDROGENATION OF PHENYLBUTENES CATALYZED BY H4Ru4(CO)82
Bianchi, Mario,Matteoli, Ugo,Frediani, Piero,Menchi, Gloria,Piacenti, Franco
, p. 317 - 325 (1983)
Phenylbutenes have been hydrogenated in the presence of H4Ru4(CO)82 to give 2-phenylbutane with a maximum optical purity of 8.5percent.Olefin isomerization is shown to lower the optical purity of the hydrogenation product.Factors affecting the st
Reaction of Grignard reagents with carbonyl compounds under continuous flow conditions
Riva,Gagliardi,Martinelli,Passarella,Vigo,Rencurosi
experimental part, p. 3242 - 3247 (2010/05/19)
This contribution details how a continuous flow reactor was used to react carbonyl compounds with Grignard reagents at room temperature in an efficient and safe manner. Flow rate, residence time and temperature were optimized for the preparation of a small collection of secondary and tertiary alcohols. Excellent yields and general applicability were observed using the set-up protocol. The procedure was also applied for the preparation of Tramadol, an analgesic drug belonging to the opioid group. The developed conditions allowed the selective addition of Grignard reagents to aldehydes and ketones in the presence of a nitrile function.
Highly alkyl-selective addition to ketones with magnesium ate complexes derived from Gignard reagents
Hatano, Manabu,Matsumura, Tokihiko,Ishihara, Kazuaki
, p. 573 - 576 (2007/10/03)
(Chemical Equation Presented) A highly efficient alkyl-selective addition to ketones with magnesium ate complexes derived from Grignard reagents and alkyllithiums is described. The nucleophilicity of R in R3MgLi is remarkably increased compared to that of the original RLi or RMgX, while the basicity of R3MgLi is decreased. Furthermore, a highly R-selective addition to ketones is demonstrated using RMe2MgLi in place of R 3MgLi.
Substituent effects on the solvolysis rates and gas phase stabilities of 1,2,2-trimethyl-1-phenylpropyl and 1,2,2-trimethyl-1-(2-methylphenyl)propyl systems
Nakata, Kazuhide,Fujio, Mizue,Mishima, Masaaki,Nomura, Hideyuki,Tsuno, Yuho,Nishimoto, Kichisuke
, p. 581 - 590 (2007/10/03)
Substituent effects on the solvolysis rates of 1,2,2-trimethyl-1- phenylpropyl chlorides in 80% (v/v) aq acetone at 45 °C and 1,2,2-trimethyl- 1-(2-methylphenyl)propyl p-nitrobenzoates in 50% (v/v) aq ethanol at 75 °C were correlated with the Yukawa-Tsuno
First enantioselective addition of diethylzinc and dimethylzinc to prostereogenic ketones catalysed by camphorsulfonamide-titanium alkoxide derivatives
Ramon, Diego J.,Yus, Miguel
, p. 5651 - 5666 (2007/10/03)
The reaction of diethylzinc or dimethylzinc with prostereogenic ketones, in the presence of a stoichiometric amount of titanium tetraisopropoxide and a catalytic amount (20%) of camphorsulfonamide derivatives as chiral ligands leads to the formation of the corresponding enantioenriched tert-alcohols with enantiomeric ratios up to 94.5 : 5.5. the best results were obtained when phenones are used as substrates independently of the dialylzinc reagent. The enantioselectivity shows a linear relationship with the enantiomeric excess of the ligand and seems to be independent of the reaction yield. A tentative catalytic cycle and mechanistic model are proposed for this new reaction.
First enantioselective addition of dialkylzinc to ketones promoted by titanium(IV) derivatives
Ramon, Diego J.,Yus, Miguel
, p. 1239 - 1242 (2007/10/03)
The reaction of dimethyl or diethylzinc with ketones in the presence of a stoichiometric amount of titanium tetraisopropoxide and a catalytic amount (20 mol %) of camphorsulfonamide derivatives as chiral ligands leads to the formation of the corresponding
Studies on the Oxidation of α-Substituted Styrenes. I. Reactivity and Formation of Reaction Products During the Oxidation of Styrene Derivatives
Suprun, Wladimir,Blau, Karla,Reinker, Kathrin
, p. 496 - 503 (2007/10/02)
The liquid phase oxidation of α-tert, -butyl, α-bromo-, α-chloro-, and α-methyl styrene with pure oxygen was investigated in a closed apparatus in chlorobenzene solution and in presence of cumene and of cumene hydroperoxide in the temperature range 35-125 deg C.The product yields were determined gaschromatographically.The difference of the activation energies of the epoxide formation and the parallel reactions were calculated.They amount to 27-38 kJ/mol.The epoxide selectivity increases with increasing temperature and decreases with increasing concentration of cumene.Relative chain propagation constants related to the tertriary CH-bond of cumene were determined from cooxidation experiments.
Solvolysis of 2-Aryl-3,3-dimethyl-2-butyl p-Nitrobenzoates. β-Deuterium Kinetic Isotope Effects and the Linear Free Energy Relationships
Liu, Kwang-Ting,Kuo, Mann-Yan
, p. 3523 - 3530 (2007/10/02)
Solvolysis of 2-aryl-3,3-dimethyl-2-butyl p-nitrobenzoates (4a-4d) and the 1,1,1-trideuterio derivatives (5a,5b,5c) in HFIP exhibited a high kinetic isotope effect, k(CH3)/k(CD3) = 1.90 at 60 deg C for the deactivating substrates 4c vs 5c.This effect decreased significantly with increasing electron releasing of the substituent on the aryl ring.Hammett-Brown treatment of the rate data for 4 yielded excellent linear relationships (r = 0.999) with ρ+ = -3.48.It is evident that the contribution of the α-methyl group to the stabilization of the cationic transition state is not constant.The approximation in the linear free energy relationship is discussed.
Novel Synthetic Route to Aryl Alkanes from Aromatic Aldehydes and Ketones. Novel Geminal Dialkylation of the Carbonyl Group of Aromatic Aldehydes and Ketones
Krief, Alain,Clarembeau, M.,Barbeaux, Ph.
, p. 457 - 458 (2007/10/02)
Benzyl-lithiums, readily available from benzyl methyl selenides and alkyl-lithiums, are efficiently alkylated; this reaction allows the geminal dialkylation of the carbonyl groups of aromatic aldehydes and ketones and the geminal aryl-alkylation of aliphatic analogues.
