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1.
The Mn(acac)3—RCN—CCl4 system was found to be efficient for the oxidation of secondary alcohols into the corresponding ketones in 80—93% yields. The oxidation proceeds through the formation of alkyl hypochlorites, which are generated from CCl4 and the alcohols in the presence of the Mn(acac)3—RCN catalytic system (R = Me, Et, and Ph).  相似文献   

2.
N-Sulfinyltrifluoromethanesulfonamide CF3SO2N=S=O reacts with salicylaldehyde, 2-furaldehyde, 2-thiophenecarbaldehyde, 3-methyl-1-phenyl-1H-pyrazole-4-carbaldehyde, and 2-phenyl-2H-1,2,3-triazole-4-carbaldehyde to afford the corresponding N-aryl(hetaryl)methylidenetrifluoromethanesulfonamides in high yields. Reactions of the latter with aniline give no adducts at the C=N bond but transamination products. The reaction of trifluoromethanesulfonamide with phenyl isocyanate led to formation of N,N′-diphenylurea instead of expected N-phenyl-N′-(trifluoromethylsulfonyl)urea.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 7, 2005, pp. 1006–1010.Original Russian Text Copyright © 2005 by Shainyan, Tolstikova.  相似文献   

3.
A study has been made of enantioselective hydrosilylation and reduction, by hydrogen transfer, of prochiral alkyl phenyl ketones or alkyl hetaryl ketones over various optically active catalysts. A total of 14 aromatic and heterocyclic carbinols were synthesized with preparative yields of 54–100%. The most effective catalytic systems were found to be complexes of RhCl3 and [Rh(cod)Cl]2 with the known optical inductor (S,S)-i-Pr-Pybox, with which we have obtained for the first time a series of heterocyclic secondary alcohols with an enantioselectivity of 20–63%.Latvian Institute of Organic Synthesis, Riga, LV-1006. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 342–358, March, 1996. Original article submitted December 11, 1995.  相似文献   

4.
A new three-component reaction between alkyl aryl(hetaryl)ketoximes, acetylene, and aliphatic ketones in the superbasic systems KOH/DMSO and LiOH/CsF/DMSO (70-90 °C, initial acetylene pressure 13-15 atm, 5-60 min) affords novel 4-methylene-3-oxa-1-azabicyclo[3.1.0]hexanes in yields of up to 75%. Using KOH/DMSO, the side products of the reaction are O-vinylketoximes and 2-aryl(hetaryl)pyrroles, while with LiOH/CsF/DMSO, the reaction proves to be selective, only minor amounts of the corresponding alkyl aryl(hetaryl) ketones being detectable.  相似文献   

5.
Reactions of α,β-unsaturated ketones with excess arylboronic acids in the presence of a rhodium catalyst generated in situ from Rh(acac)(C2H4) and (S)-P-Phos in dioxane/water at 100°C gave high yields of the corresponding products in up to 99% ee.  相似文献   

6.
A substoichiometric amount of titanium tetrachloride was found to be effective to promote and participate in the tandem α-hydroxyalkylation/β-chlorination of α,β-acetylenic ketones in the presence of (n-Bu)4NI. This method provides the concise synthesis of (E)-β-halo Baylis–Hillman adducts. No β-iodo products were detected when using this combination of halogen sources. The reaction process involves 1,4-addition of chloro anion released from TiCl4 onto α,β-acetylenic ketones to give TiCl3–allenolate intermediates followed by the titanium Lewis acid-promoted carbonyl addition. Modest to good yields (53–77%) and excellent E/Z stereoselectivity (>95%) have been obtained for 10 examples.  相似文献   

7.
We found that the reaction of cyclopropanecarboxylic acid N′-substituted-hydrazides with PPh3/CCl4 proceeded smoothly to give the corresponding normal Robinson-Gabriel type product 2-cyclopropyl-5-substituted-[1,3,4]-oxadiazoles in good yields. Using CBr4 or CI4 instead of CCl4 in the above system, the ring opening of cyclopropane occurred after dehydration to give the corresponding 2-(3-halopropyl)-5-substituted-[1,3,4]-oxadiazoles (4 or 5) in good yields.  相似文献   

8.
The RuCl3 and RuO2·nH2O catalyzed oxidation of alkanes, aromatic fatty acids, alcohols, citronellol, and hydroxycitronellol by NaOCl was studied in the diphase system CCl4-aqueous NaOCl at pH 13–13.5. At 60–65°C, using 1–2 mole % of catalyst and a 1.5-fold molar excess of NaOCl, primary alkanols (hexanol-1, 2-ethylhexanol-1, decanol-1, hexadecanol-1) benzyl and 3-phenyl-propyl alcohols, and hydroxycitronellol are converted to the corresponding aldehydes with a selectivity of 70–90% and a yield of over 75%.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 115–121, January, 1991.  相似文献   

9.
Synthesis of Macrocyclic Ketones by Ring-Enlargement Reactions; a New Path to (±)-Muscone A new synthetic route to macrocyclic ketones is described. Starting from 2-nitrocycloalkanones, the ring-enlarged compounds of the type 4 and 5 were prepared in three steps. Reduction of the NO2 group with Bu3SnH and azobisisobutyronitrile led in moderate yields to simple β-keto-esters which were quantitatively hydrolyzed and decarboxylated to the ketones of the type 8 and 9 . The interesting fragrances Exaltone® ( 8a ) and (±)-muscone ( 9a ) were prepared in this way in overall yields of 22 and 18%, respectively.  相似文献   

10.
Summary Deuteration technique was applied to study the micro structures of copolymer series VDC/VC by infrared spectroscopy and high resolution NMR. The CH2 bending modes of chlorine atom containing polymers assigned as follows; –CCl2CH2CCl2– 1405 cm–1 (cryst.) and 1410 cm–1 (amorph.), –CHClCH2CCl2– 1422 cm–1, –CHClCH2CHCl– 1428 cm–1 (cryst.) and 1432 cm–1 (amorph.) –CHClCH2CH2CHCl– 1445 cm–1 and –CCl2CH2CH2CCl2– 1448 cm–1. This infrared interpretation shows that only the head to tail addition occurs in the copolymerisation. Nine peaks of the methylene protons were observed clearly in the NMR spectra of the copolymers. The study of the deuterated copolymers revealed that the effects of the chemical groups until the third at both sides from the marked methylene and the stereo configuration of long VC part should be considered to assign the NMR spectra. The CCl2 group made the chemical shift of the methylene proton to appear at lower magnetic field and the CHCl group gave the opposite behavior.
Zusammenfassung Mit deuterierten Monomeren wurde die Mikrostruktur der Copolymerenserie Vinyliden-Chlorid/Vinyl-Chlorid im Infraroten und mit hochauflösender Kernresonanz untersucht. Für die Biegeschwingung der Chloratome enthaltenden Polymeren der Methylengruppe ergeben sich folgende Werte: –CCl2CH2CCl2– 1405 cm–1 (krist.) und 1410 cm–1 (amorph.), –CHClCH2CCl2– 1422 cm–1, –CHClCH2CHCl– 1428 cm–1 (krist.) und 1432 cm–1 (amorph.), –CHClCH2CH2CHCl– 1445 cm–1 und –CCl2CH2CH2CCl2– 1448 cm–1.Diese Interpretation des Infraroten zeigt, daß nur die Kopf-Schwanz-Addition bei der Copolymerisation stattfindet. Neun Maxima des Methylenprotons wurden deutlich in den NMR-Spektren der Copolymeren beobachtet. Die Untersuchungen an den deuterierten Copolymeren zeigen, daß die Effekte der chemischen Gruppen bis zur dritten nach beiden Seiten vom markierten Methylen und die Stereokonfiguration von langen Vinyl-Chlorid-Anteilen betrachtet werden müssen, um die NMR-Spektren zu beschreiben. Die CCl2-Gruppe läßt die chemische Verschiebung des Methylen-protons bei geringeren magnetischen Feldern und die CHCl-Gruppe bei höheren erscheinen.


With 5 figures in 13 details and 4 tables  相似文献   

11.
Reactions involving the interphase dichloro-and dibromocyclopropanation of 2H- and 4H-chromenes that contain ethoxy, aryl, alkyl, and hetaryl substituents in the pyran ring were studied. It is shown that products of addition of dihalocarbenes to the double bond of the chromenes are formed in high yields in all cases.Deceased.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 163–166, February, 1982.  相似文献   

12.
Summary Halo-compounds of which the half-wave reduction potential is equal to or less negative than that of carbon tetrachloride, are reduced by tetrachloroferrate(II) anions. The bimolecular rate constants measured at 250 in isopropanol are 2 × 10–5 M–1 s–1 and 1 × 10–4 M–1 s–1 respectively for CCl4 and CCl3CO2Me.  相似文献   

13.
Alkanes and cycloalkanes (isobutane, butane, isopentane, isohexane, and methylcyclopentane) react with benzene or bromobenzene at 0–20 °C in the presence of RCO+Al2X7 complexes (R=Me, Pr, or Ph; X=Cl or Br) to give products of the alkylacylation of arenes. The yields of alkylated aromatic ketones reach 60–87 % in 5–30 min, whereas the yields of unalkylated aromatic ketones (the competitive reaction) reach 0–40 %. The reactions of isobutane or isopentane with benzene result exclusively inpara isomers oft-BuC6H4COR or a mixture of Me2(Et)CC6H4COR and Me(i-Pr)CHC6H4COR isomers (11), respectively. The reaction of isobutane with benzene also proceeds regioselectively and gives only one isomer, 2-Br-t-BuC6H4COR.For Part 2 seeIzv. Akad. Nauk, Ser. Khim., 1991, No 1, 105 [Bull. Acad. Sci. USSR. Div. Chem. Sci., 1991, No 1, 90 (Engl. Transl)].Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1253–1257, July, 1993.The authors express their gratitude to B. I. Bakhmutov for his assistance in interpreting the spectra.  相似文献   

14.
Reduction of the carbonyl groups in cyclic and acyclic 2-diazo-1,3-diketones with sodium tetrahydridoborate in aqueous–alcoholic medium, followed by hydrolysis of the reaction mixture over wet silica gel and chromatographic purification on neutral aluminum oxide, afforded 1,3-dialkyl-3-hydroxy-2-diazoketones in 58–87% yield. Bulky substituents at the carbonyl group considerably reduce the efficiency of the process, and the reduction of cis- and trans-4,6-di-tert-butyl-2-diazocyclohexane-1,3-diones is characterized by low stereoselectivity (de 40–49%). In the IR spectra of 3-hydroxy-2-diazocyclohexanes, absorption bands corresponding to stretching vibrations of free axial hydroxy groups are located at higher frequencies (by 20-45 cm-1) than those belonging to equatorial hydroxy groups. These parameters may be useful for conformational analysis of cyclic hydroxy diazo ketones. Stabilization of the E conformation of acyclic hydroxy diazo ketones via intramolecular hydrogen bonding is likely to occur only in nonpolar solvents (CCl4, cyclohexane).  相似文献   

15.
Promoted by stannous salts, 1,1,1-trichloro-2,2,2-trifluoroethane reacts readily with aliphatic, aromatic, and α, β-unsaturated aldehydes giving the corresponding alcohols bearing a CF3CCl2-moiety in good to excellent yields. These alcohols are farther oxidized by Jones reagent giving the corresponding ketones in high yields.  相似文献   

16.
Pd salts catalyse oxidation of alcohols with CCl4 in the presence of K2CO3. Primary alcohols are oxidised to esters, and secondary alcohols to ketones. CCl4 is converted to CHCl3. The reaction of allylic alcohols bearing a terminal olefinic bond with CCl4 or BrCCl3 in the presence of palladium catalyst at 110° affords 4,4,4-trichloro ketones. At 40°, simple adducts of CCl4 or BrCCl3 having a halohydrin structure are obtained, which are converted to the corresponding trichloro ketones by the catalysis of palladium. Various halohydrins are converted to ketones by Pd catalysis.  相似文献   

17.
The reactions of 2- and 3-dichloromethylpyridines and dichloromethylpyrazine with carbon tetrachloride in the presence of aqueous or solid alkali and an interphase catalyst lead to the corresponding trichloromethyl-substituted azines. The CCl4-solid KOH-18-crown-6 system, in the use of which trichloromethyl-substituted heterocycles were obtained in preparative yields, was the most effective.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 50–53, January, 1990.  相似文献   

18.
In the decomposition of CCl4 in an r.f. pulse discharge the observation of time-resolved absorption spectra of the CCl radical allowed concentration measurements and a kinetic and mechanistic investigation of the system. Kinetic spectroscopy and end product analysis, with computer simulation of proposed mechanisms, indicates that the major decomposition reaction is CCl4»CCl+3Cl (Cl2+Cl), with a minor contribution from CCl4»CCl2+2Cl. Radical concentrations were of the order of 10–7 mol dm–3 (1014 molec. cm–3). CCl removal was kinetically second order with a rate coefficient value of (3.7±8)×1010 mol–1 dm–3 s–1 at 295±3 K at gas pressure 0.1 torr.  相似文献   

19.
Reactions of alkynelsufenamides with olefins (such as cyclohexene, norbornene, 1-hexene, 1-octene, allylbenzene, and styrene) in the presence of phosphoryl halides (POCl3, POBr3) afforded 70–95% of β-halo-substituted alkyl alkynyl sulfides. The reactions with cyclohexene and norbornene are characterized by trans stereoselectivity. Alkynylsulfenylation of terminal alkyl- and benzylacetylenes occurs in a regioselective fashion with predominant formation of the corresponding anti-Markownikoff adducts, while the addition to styrene yields halogen-containing sulfides according to the Markownikoff rule.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 7, 2005, pp. 977–982.Original Russian Text Copyright © 2005 by Beloglazkina, Belova, Dubinina, Garkusha, Buryak, Zyk.  相似文献   

20.
The catalyst FeIIFe2 IIICl8 (DMA)6-iron(2+)diiron(3+)octachlorohexakis(dimethylacetamide), was isolated from the media of the catalytic synthesis of 1,1,1,3-tetrachloropropane (C3), and characterized by physicochemical methods. A counter synthesis of the catalyst was carried out. The telomerization of ethylene with CCl4 proceeds with a 98% selectivity with respect to C3 in its presence, while the conversion of CCl4, reaches 55–60% after 4 h. A coordination-ionic mechanism of the reaction of CCl4 with C2H4 was proposed, which followed the concept of the donor-accpetor electron-transporting systems (the DAET systems), thus accounting for its high selectivity.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2794–2798. December, 1990.  相似文献   

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