- One-pot catalyst-free synthesis of β-and γ-hydroxy sulfides using diaryliodonium salts and microwave irradiation
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A simple and rapid one-pot protocol is described for the preparation of α- and β-hydroxy sulfides. The direct solvent-free microwave irradiation of diaryliodonium salts, potassium thiocyanate, and ethylene glycol/β-propylene glycol without any catalyst or base affords the final compounds in good yields (65-95 %) in around 10-25 min. Copyright
- Vaddula, Buchi Reddy,Varma, Rajender S.,Leazer, John
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p. 6852 - 6855
(2013/02/22)
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- Stereo- and regioselective thiolysis of 1,2-epoxides in water
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A simple, efficient, stereoselective, and highly regioselective procedure for the synthesis of β-hydroxy sulfides by thiolysis of various 1,2-epoxides in water as a solvent, using no catalyst and under very mild conditions, is described. Copyright Taylor
- Movassagh, Barahman,Soleiman-Beigi, Mohammad
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p. 3239 - 3244
(2008/02/12)
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- Method for the dihydroxylation of olefins using transition metal catalysts
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This invention relates to process for dihydroxylation of olefins using transition metal catalysts to obtain monofunctional, bifunctional, and/or polyfunctional 1,2-diols of the formula (I) R1R2C(OH)—C(OH)R3R4??(I) where R1to R4are defined herein, by reacting an olefin of the formula (II) R1R2C═CR3R4??(II) where R1to R4are defined as for formula (I), with molecular oxygen in the presence of an osmium, ruthenium, or manganese compound in water or a water-containing solvent mixture at a pH of from 7.5 to 13.
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Page column 9
(2008/06/13)
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- ZnCl2 as an Efficient Catalyst in the Thiolysis of 1,2-Epoxides by Thiophenol in Aqueous Medium
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ZnCl2 (5 mol%) is an efficient catalyst for the thiolysis of 1,2-epoxides by thiophenol in water at pH 4.0. A variety of β-hydroxy phenylsulfides were obtained in short reaction times and excellent yields. Starting from cyclohexene oxide (1), two one-pot multi-step procedures in sole water (thiolysis/oxidation with H2O2) have been realized, for the chemoselective synthesis of the corresponding β-hydroxysulfoxides 19 or for the related β-hydroxysulfone 20.
- Amantini, David,Fringuelli, Francesco,Pizzo, Ferdinando,Tortoioli, Simone,Vaccaro, Luigi
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p. 2292 - 2296
(2007/10/03)
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- Naphthyloxy acetic acid derivatives and a pharmaceutical composition comprising them as an active ingredient
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The naphthyloxyacetic acid derivatives of the formula (I) wherein A is H, -(alkylene)COOR1, -(alkylene)CONR2R3, -(alkylene)OH, -(alkylene)tetrazole, -(alkylene)CN; E is single bond or alkylene; G is —S—, —SO—, —SO2—, —O— or —NR4—; L is alkylene, —(CH2)m—CH═CH—(CH2)n— or —(CH2)x—CH(OH)—(CH2)y—; M is phenyl, phenyl(thio, oxy, amino), diphenylmethyl, diphenylmethyl(thio, oxy, amino), and pharmaceutical composition comprising them as an active ingradient. The compounds of the formula (I) can combine PGE2receptor and exhibit the activity to antagonize or agonize for PGE2receptor. Therefore, they are useful as anti-hyperlipemia, for the prevention of abortion, for analgesics, as antidiarrheals, sleep inducer, diuretic, anti-diabetes, abortient, cathartics, antiulcer, anti-gastritis or antihypertensive etc.
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Example 6(5)
(2010/11/29)
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- Osmium-Catalyzed Dihydroxylation of Olefins Using Dioxygen or Air as the Terminal Oxidant
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The osmium-catalyzed dihydroxylation of various olefins using molecular oxygen or air as the stoichiometric oxidant is reported. Aromatic olefins yield the corresponding diols in good to excellent chemoselectivities under optimized pH conditions (pH = 10.4-12.0). Air can be used under moderate pressures (3-9 bar) instead of dioxygen as the reoxidant. By increasing the oxygen content of the solution, it is possible to achieve highly efficient conversion at low catalyst amount (catalyst/substrate = 1:4000). Tri- and tetrasubstituted olefins are oxidized at pH > 11 to give the corresponding 1,2-diols in good to very good yields without requiring the addition of sulfonamides or other hydrolysis agents. Studies of the dihydroxylation of functionalized olefins demonstrate that the reaction conditions tolerate a variety of functional groups. In the presence of dihydroquinine or dihydroquinidine derivatives (Sharpless ligands), asymmetric dihydroxylations occur with lower enantioselectivities than tose of the classical K3[Fe(CN)6] reoxidation system.
- Doebler, Christian,Mehltretter, Gerald M.,Sundermeier, Uta,Beller, Matthias
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p. 10289 - 10289
(2007/10/03)
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- Facile synthesis of vinyl sulfones from β-bromo alcohols
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Vinyl sulfones are synthesized in good yields by dehydration of β- hydroxy sulfones derived from β-bromo alcohols.
- Lee, Jae Wook,Lee, Chi-Wan,Jung, Jin Hang,Oh, Dong Young
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p. 2897 - 2902
(2007/10/03)
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- Dihydroxylation and oxidative cleavage of olefins in the presence of sulfur
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The dihydroxylation of olefins using AD-mix or OsO4/K3Fe(CN)6 in the presence of sulfides has been examined as has the rate of oxidation of various classes of sulfides. The selectivity of olefin oxidation in preference to sulfur oxidation depends on the nature of the sulfur moiety, and can be problematic for certain classes of substrates.
- Sammakia, Tarek,Hurley, T. Brian,Sammond, Douglas M.,Smith, Randall S.,Sobolov, Susan B.,Oeschger, Thomas R.
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p. 4427 - 4430
(2007/10/03)
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- FUNCTIONALLY SUBSITUTED SULFUR-CONTAINING COMPOUNDS. 9. REASTIONS OF 2-OXIRANES WITH ACETIC ANHYDRIDE AND ACETYL CHLORIDE
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Reaction of 2-oxiranes with acetic anhydride gives a mixture of 3-(organylthio)-1,2-diacetoxypropane and 2-(organylthio)-1,3-diacetoxypropane, and with acetyl chloride a mixture of 2-chloro-3-(organylthio)-1-acetoxypropane and 3-chloro-2-(organylthio)-1-acetoxypropane.In both cases, the ratio of the isomers depends on the nature of the organylthio group and on the nature of the electrophile.
- Kalugin, V. E.,Litvinov, V. P.
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p. 1391 - 1394
(2007/10/02)
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- Formation of Optically Active Aryloxyacetaldehyde Cyanohydrin Acetates with the Aid of a Microorganism
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Microorganisms that hydrolyze the one enantiomer of dl-phenoxyacetaldehyde cyanohydrin acetate were screened, and Bacillus coagulans isolated from soil was found to be the best.This bacterium was applied to the asymmetric hydrolysis of other aryloxyacetaldehyde derivatives to give satisfactory results.The effect of adding dimethyl sulfoxide to the medium is also described.
- Ohta, Hiromichi,Miyamae, Yoshitaka,Tsuchihashi, Gen-ichi
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p. 215 - 222
(2007/10/02)
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- Regioselective Synthesis of Hydroxy Sulphides via Trifluoroacetoxysulphenylation of Derivatives of Allylic Alcohols
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Reaction of manganese(III) acetate with diphenyl disulphide in dichloromethane-trifluoroacetic acid in the presence of allylic esters gives trifluoroacetoxy sulphides, which on hydrolysis readily afford vicinal hydroxy sulphides.With acetate esters, neighbouring group participation by the acetate functionality controls the reaction course.Thus regiospecific addition to allyl acetate affords after hydrolysis only 3-phenylthiopropane-1,2-diol.In contrast, with trifluoroacetate esters the inductive effects of the trifluoroacetate functionality lead to a different regiocontrol.Thus addition of diphenyl disulphide to allyl trifluoroacetate gives after hydrolysis only 2-phenylthiopropane-1,3-diol.The regio- and stereochemistry of addition to a variety of other allylic (and homoallylic) esters is described and the extension of this type of regiocontrol is discussed.
- Samii, Zakaria K. M. Abd El,Ashmawy, Mohamed I. Al,Mellor, John M.
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p. 2509 - 2516
(2007/10/02)
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- Synthesis of Functionally Substituted α,β-Unsaturated Carbonyl Compounds
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Epichlorohydrin and glycidol are transformed in a four step sequence into β-dimethylamino-α-phenylthio-substituted α,β-unsaturated carbonyl compounds 5, possessing differently O-protected oxymethyl substituents at the carbonyl group.These compounds are of
- Apparao, Satyam,Schmidt, Richard R.
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p. 896 - 899
(2007/10/02)
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- Ouverture d'epoxydes par le N-hydroxycarbamates de methyle; syntheses de tetrahydrodioxazine-1,4,2 ones-3 et de carbomethoxy-2 tetrahydrodioxazines-1,4,2
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The ring opening of epoxides in a basic medium by methyl N-hydroxycarbamate reacting as an N-protected hydroxylamine by its oxanion CH3O-CO-NHO(-) gives the corresponding carbomethoxyaminoxyalcohols 2.These compounds can react further to give: N,O-di(hydroxy-2' alkyl)hydroxylamines 3 by opening of a second epoxide molecule; diols RCH(OH)CH2OH 4 by rupture in basic medium of the N-O linkage of 2; 1,4,2-tetrahydrodioxazine-3 ones 5 by intramolecular cyclisation of 2.The oxanion CH3O-CO-NHO(-) attacks the primary carbon of the epoxide except in the case of epoxystyrene where as minor attack on the secondary carbon is also observed.The cyclization of carbomethoxyaminoxyalcohols 2 with aldehydes or their corresponding acetals in the presence of paratoluene sulfonic acid is a rapid and easy two step synthesis of 2-carbomethoxy-tetrahydrodioxazines-1,4,2 8.
- Fruchier, Alain,Moragues, Veronique,Petrus, Clement,Petrus, Francoise
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p. 173 - 182
(2007/10/02)
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