3123-98-6Relevant academic research and scientific papers
CH3ReO3/H2O2 in room temperature ionic liquids: An homogeneous recyclable catalytic system for the Baeyer-Villiger reaction
Bernini, Roberta,Coratti, Antonietta,Fabrizi, Giancarlo,Goggiamani, Antonella
, p. 8991 - 8994 (2007/10/03)
The Baeyer-Villiger oxidation of cyclic ketones can be effected by methyltrioxorhenium/hydrogen peroxide in the ionic liquid [bmim]BF4. After simple extraction of the lactone with diethyl ether, the catalyst can be repeatedly recycled and efficiently reused for the lactonisation process in the same reaction medium.
Autocatalytic oxidation of ethers with sodium bromate
Metsger, Leonid,Bittner, Shmuel
, p. 1905 - 1910 (2007/10/03)
Sodium and potassium bromate are stable and easily stored oxidants. They can oxidize both open and cyclic ethers in aqueous solution at room temperature yielding esters and lactones. Kinetic studies of the oxidation of tetrahydrofuran to γ-butyrolactone indicate that the major active oxidation species is bromine and not bromate. The bromate is only a supporting agent, responsible for the initiation step and supplying bromine molecules by oxidizing bromide ions during the propagation step. In the oxidation of tetrahydrofuran, high yields of γ-butyrolactone were obtained. (C) 2000 Elsevier Science Ltd.
Oxidation of acetals, an orthoester, and ethers by dioxiranes through α-CH insertion
Curci,D'Accolti,Fiorentino,Fusco,Adam,Gonzalez-Nunez,Mello
, p. 4225 - 4228 (2007/10/02)
Dimethyldioxirane (1a) and methyl(trifluoromethyl)dioxirane (1b) efficiently afford cleavage of acetals and of ketals to carbonyl products under mild, neural conditions. Dialkyl ethers are cleaved to alcohols, aldehydes and/or carboxylic acids, whereas reaction of dioxiranes 1a,b with medium-ring cyclic ethers transforms the latter into lactones, via the corresponding hemiacetals, with no appreciable formation of ring-opened products. The products can be accounted for on grounds of a remarkably selective O-atom insertion by the dioxirane into C-H bonds α to the ether functionality.
HIGHLY REGIOSELECTIVE RING-OPENING OF α-SUBSTITUTED CYCLIC ACID ANHYDRIDES CATALYZED BY LIPASE
Hiratake, Jun,Yamamoto, Kazuyoshi,Yamamoto, Yukio,Oda, Jun'ichi
, p. 1555 - 1556 (2007/10/02)
Lipase Amano P irreversibly catalyzed a ring-opening of α-substituted cyclic acid anhydrides 1 preferentially at the less hindered carbonyl group to give monoesters with high regioselectivity.
Ruthenium Complex Catalyzed Regioselective Dehydrogenation of Unsymmetrical α,ω-Diols
Ishii, Youichi,Osakada, Kohtaro,Ikariya, Takao,Saburi, Masahiko,Yoshikawa, Sadao
, p. 2034 - 2039 (2007/10/02)
Ruthenium complex catalyzed regioselective dehydrogenation of unsymmetrically substituted 1,4- and 1,5-diols in the presence of such a hydrogen acceptor as α,β-unsaturated ketone gave predominantly β-substituted γ-lactones and γ-substituted δ-lactones, respectively.Among the ruthenium complexes, RuH2(PPh3)4 was the most active and selective catalyst and showed high catalytic activity even at 20 deg C.For example, 2,2-dimethyl-1,4-butanediol was quantitatively converted to dihydro-4,4-dimethyl-2(3H)-furanone and dihydro-3,3-dimethyl-2(3H)-furanone in a ratio of 99.6/0.4 in the presence of 4-phenyl-3-buten-2-one (hydrogen acceptor) and a catalytic amount of RuH2(PPh3)4 at 20 deg C.The proposed main factor controlling the regioselectivity is the steric constraints produced by the substituent(s) of a diol at the coordination step of alkoxy group to ruthenium.
Regioselective Hydrogenation of Unsymmetrically Substituted Cyclic Anhydrides Catalyzed by Ruthenium Complexes with Phosphine Ligands
Ikariya, Takao,Osakada, Kohtaro,Ishii, Youichi,Osawa, Shoichi,Saburi, Masahiko,Yoshikawa, Sadao
, p. 897 - 898 (2007/10/02)
Regioselective hydrogenation of unsymmetrically substituted cyclic anhydrides catalyzed by ruthenium complexes with mono-, di-, or triphosphine ligands produced the corresponding two isomeric lactones, where the regioselectivity was influenced by the bulkiness of substituent(s) on the anhydrides and of the phosphine ligands of catalyst.
Polystyrene-Bound Phenylselenic Acid: Catalytic Oxydations of Olefins, Ketones, and Aromatic Systems
Taylor, Richard T.,Flood, Lawrence A.
, p. 5160 - 5164 (2007/10/02)
A new synthesis of polystyrene-bound phenylselenic acid, from reaction of mercurated polystyrene and selenium dioxide, is described.A triphasic system of the polymer (in catalytic amounts), aqueous hydrogen peroxide, and dichloromethane is shown to be an effective medium for the conversion of olefins into trans diols and ketones into esters.A biphasic system of the polymer and tert-butyl hydroperoxide in refluxing chloroform effects the selective oxidation of benzylic alcohols to the carbonyl species.In a similar catalytic system hydroxy aromatic compounds can be converted into quinones.Conversion of 1,5-dihydroxynaphthalene into juglone can be realized in 70percent yield.
CATALYTIC REGIOSELECTIVE DEHYDROGENATION OF UNSYMMETRICAL α,ω-DIOLS USING RUTHENIUM COMPLEXES
Ishii, Youichi,Osakada, Kohtaro,Ikariya, Takao,Saburi, Masahiko,Yoshikawa, Sadao
, p. 2677 - 2680 (2007/10/02)
Ruthenium complex catalyzed regioselective dehydrogenation of unsymmetrically substituted 1,4- and 1,5-diols in the presence of α,β-unsaturated ketone as a hydrogen acceptor and triethylamine gave β-substituted γ-lactones and γ-substituted δ-lactones as major products, respectively.
