- Baeyer–Villiger Oxidation of Cyclohexanone by Hydrogen Peroxide with Fe3O4@GO as Catalyst Under Solvent Free Conditions
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Abstract: An efficient magnetic nanocomposite catalyst (Fe3O4@GO) was synthesized and utilized as a sustainable and convenient catalyst for Baeyer–Villiger oxidation. The catalyst was characterized by XRD, FT-IR, TEM, SEM, XPS, Raman
- Xiao, Guansheng,Gao, Xi,Yan, Weiting,Wu, Tao,Peng, Xinhua
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- 3D-Network porous polymer bonded metalloporphyrin: An efficient and reusable catalyst for the Baeyer-Villiger oxidation
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A new, green catalyst was prepared through immobilization of metalloporphyrin on the surface of 3D-network polymer based on calix[4]resorcinarene (PC4RA), which efficiently catalyze B-V oxidation reaction using O2/benzaldehyde. The catalyst demonstrated excellent activity, which is highly potential for cyclic aliphatic ketones oxidation under mild conditions. IR spectroscopy, UV-Vis spectroscopy, thermal gravimetric analysis, energy dispersive spectroscopy and scanning electron microscopy are some of the spectroscopic methods used to characterize the new synthesized solid support.
- Hamid, Sheida,Mouradzadegun, Arash
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- Microwave-Enhanced Coupling of Carboxylic Acids with Liquid Ketones and Cyclic Ethers Using Tetrabutylammonium Iodide/ t-Butyl Hydroperoxide
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The oxidative coupling of carboxylic acids with liquid ketones and cyclic ethers has been accomplished in minutes using t-butyl hydroperoxide in the presence of tetrabutylammonium iodide under microwave irradiation in the absence of a solvent. In addition to drastically shortening the reaction times, the use of microwaves resulted, in general, in yields equal to or higher than those obtained by conventional heating.
- Macías-Benítez, Pablo,Moreno-Dorado, F. Javier,Guerra, Francisco M.
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p. 6027 - 6043
(2020/05/22)
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- Chemoselective Oxidation of Equatorial Alcohols with N-Ligated λ3-Iodanes
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The site-selective and chemoselective functionalization of alcohols in complex polyols remains a formidable synthetic challenge. Whereas significant advancements have been made in selective derivatization at the oxygen center, chemoselective oxidation to the corresponding carbonyls is less developed. In cyclic systems, whereas the selective oxidation of axial alcohols is well known, a complementary equatorial selective process has not yet been reported. Herein we report the utility of nitrogen-ligated (bis)cationic λ3-iodanes (N-HVIs) for alcohol oxidation and their unprecedented levels of selectivity for the oxidation of equatorial over axial alcohols. The conditions are mild, and the simple pyridine-ligated reagent (Py-HVI) is readily synthesized from commercial PhI(OAc)2 and can be either isolated or generated in situ. Conformational selectivity is demonstrated in both flexible 1,2-substituted cyclohexanols and rigid polyol scaffolds, providing chemists with a novel tool for chemoselective oxidation.
- Mikhael, Myriam,Adler, Sophia A.,Wengryniuk, Sarah E.
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p. 5889 - 5893
(2019/08/26)
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- Novel and efficient transformation of enamides into α-acyloxy ketones via an acyl intramolecular migration process
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Hydrogen peroxide and anhydride mediated transformation of enamides to afford substituted α-acyloxy ketones is described. This transition-metal-free cascade reaction has a broad substrate scope and high efficiency. The acyl intramolecular migration procedure successfully achieved this acyloxylation process under mild conditions and increased the atom efficiency.
- Zhou, Xiaoqiang,Ma, Haojie,Cao, Jinhui,Liu, Xingxing,Huang, Guosheng
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supporting information
p. 10070 - 10073
(2016/11/06)
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- A Counterion-Directed Approach to the Diels–Alder Paradigm: Cascade Synthesis of Tricyclic Fused Cyclopropanes
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An approach to the intramolecular Diels–Alder reaction has led to a cascade synthesis of complex carbocycles composed of three fused rings and up to five stereocenters with complete stereocontrol. Computational analysis reveals that the reaction proceeds
- Kiss, Emily,Campbell, Craig D.,Driver, Russell W.,Jolliffe, John D.,Lang, Rosemary,Sergeieva, Tetiana,Okovytyy, Sergiy,Paton, Robert S.,Smith, Martin D.
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supporting information
p. 13813 - 13817
(2016/10/26)
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- Flexible stereoselective functionalizations of ketones through umpolung with hypervalent iodine reagents
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The functionalization of carbonyl compounds in the α-position has gathered much attention as a synthetic route because of the wide biological importance of such products. Through polarity reversal, or "umpolung", we show here that typical nucleophiles, such as oxygen, nitrogen, and even carbon nucleophiles, can be used for addition reactions after tethering them to enol ethers. Our findings allow novel retrosynthetic planning and rapid assembly of structures previously accessible only by multistep sequences. A Nu approach: An efficient α-functionalization of ketones with a range of simple and useful nucleophiles is possible by using hypervalent iodine reagents (see scheme; Nu′ can be the Nu itself or a protected form of this nucleophile group).
- Mizar, Pushpak,Wirth, Thomas
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p. 5993 - 5997
(2014/06/10)
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- Silver acetate mediated acetoxylations of alkyl halides
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Silver acetate promotes the acetoxylation of alkyl halides under neutral reaction conditions. The reaction is applicable to primary and activated secondary alkyl halides, and 2,2-dibromoacetophenones for preparing the corresponding acetates in good yields. The presence of ester, amide, nitrile, hydroxy, and OTBDMS functions on the substrate is tolerated.
- Nolla-Saltiel, Roberto,Carrillo-Arcos, Ulises Alonso,Porcel, Susana
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supporting information
p. 165 - 169
(2014/03/21)
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- A multicatalyst system for the one-pot desymmetrization/oxidation of meso-1,2-alkane diols
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Two is better than one: We demonstrate the viability of an organocatalytic reaction sequence along a short peptide backbone that carries two independent catalytic functionalities, which allow the rapid, one-pot acylative desymmetrization and oxidation of meso-alkane-1,2-diols to the corresponding acetylated acetoins with good yields and enantioselectivities (see scheme). Copyright
- Mueller, Christian E.,Hrdina, Radim,Wende, Raffael C.,Schreiner, Peter R.
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supporting information; experimental part
p. 6309 - 6314
(2011/08/07)
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- An efficient method for the α-acetoxylation of ketones
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α-Acetoxylation of ketones catalyzed by iodobenzene using 30% aqueous hydrogen peroxide and acetic anhydride as the oxidant is an effective and economical method for the preparation of a-acetoxy ketones. The reaction gave the products in good yields witho
- Sheng, Jinmei,Li, Xiaolong,Tang, Mingfang,Gao, Botao,Huang, Guosheng
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p. 1165 - 1168
(2008/02/03)
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- Simple and efficient MW-assisted cleavage of acetals and ketals in pure water
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Simple and efficient MW-assisted cleavage of acetal and ketal is proposed in deionized water and in a very short time.
- Procopio, Antonio,Gaspari, Marco,Nardi, Monica,Oliverio, Manuela,Tagarelli, Antonio,Sindona, Giovanni
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p. 8623 - 8627
(2008/03/30)
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- Lewis acid-promoted α-hydroxy β-dicarbonyl to α-ketol ester rearrangement
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The decarbomethoxylation reaction of a substituted α-hydroxy-α-carbomethoxy pentacyclic substituted ketone, used as an advanced intermediate in the synthesis of the alkaloid aspidophytine, can be effected by heating with MgI2 in CH3CN. The reaction was shown to proceed by a novel α-hydroxy β-dicarbonyl to α-ketol ester rearrangement. It was possible to isolate a carbonate intermediate in 75% yield, thereby providing support for the proposed pathway.
- Hong, Xuechuan,Mejía-Oneto, José M.,Padwa, Albert
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p. 8387 - 8390
(2007/10/03)
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- A general method for the α-acyloxylation of carbonyl compounds
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(Chemical Equation Presented) A simple, one-pot method for the α-acyloxylation of carbonyl compounds that proceeds at room temperature in the presence of both moisture and air has been developed. Treatment of a variety of aldehydes and both cyclic and acy
- Beshara, Cory S.,Hall, Adrian,Jenkins, Robert L.,Jones, Kerri L.,Jones, Teyrnon C.,Killeen, Niall M.,Taylor, Paul H.,Thomas, Stephen P.,Tomkinson, Nicholas C. O.
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p. 5729 - 5732
(2007/10/03)
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- Chemoenzymatic synthesis of α′- And α-acetoxylated cyclic ketones
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α,β-Unsaturated and saturated cyclic ketones were selectively oxidized at the α′- and α-positions using Mn(OAc)3 and Pb(OAc)4, respectively, resulting in high chemical yields. The resultant racemic α′- and α-acetoxylated substrates were resolved into corresponding enantiomerically enriched α′- and α-hydroxylated and acetoxylated compounds with 96-98% ee via PLE hydrolysis. The absolute configurations of α′-acetoxy-α,β-unsaturated cyclic ketones were determined by transforming them into the corresponding saturated α-acetoxy cyclic ketones of known absolute configuration.
- Tanyeli, Cihangir,Turkut, Engin,Akhmedov, Idris Mecidoglu
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p. 1729 - 1733
(2007/10/03)
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- The intramolecular Baylis-Hillman reaction: Easy preparation of versatile substrates, facile reactions, and synthetic applications
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We have developed a general and highly efficient method for the preparation of diverse ω-formyl-aα,β-unsaturated carbonyl compounds and optimized the conditions for the intramolecular Baylis-Hillman reactions of these compounds to provide various biologic
- Yeo, Jung Eun,Yang, Xiuling,Kim, Hee Jin,Koo, Sangho
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p. 236 - 237
(2007/10/03)
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- Er(OTf)3 as a mild cleaving agents for acetals and ketals
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Er(OTf)3 is proposed as a very gentle Lewis acid catalyst in a chemoselective method for the cleavage of alkyl and cyclic acetals and ketals at room temperature in wet nitromethane is presented.
- Dalpozzo, Renato,De Nino, Antonio,Maiuolo, Loredana,Nardi, Monica,Procopio, Antonio,Tagarelli, Antonio
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p. 496 - 498
(2007/10/03)
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- Reinvestigation of the synthetic and mechanistic aspects of Mn(III) acetate mediated oxidation of enones
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Mn(OAc)3 mediated α′-acetoxylation of α,β-unsaturated enones is reinvestigated from a synthetic and mechanistic point of view and an improved procedure based on the use of acetic acid as a co-solvent is presented. Excellent results were obtained for a variety of structurally diverse and synthetically important enones under the optimized conditions.
- Demir, Ayhan S.,Reis, ?mer,Igdir, A. Cigdem
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p. 3427 - 3432
(2007/10/03)
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- Highly efficient and versatile acetylation of alcohols catalyzed by cerium(III) triflate
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Cerium(III) triflate is a powerful catalyst for the acetylation of alcohols. The reaction works well for a large variety of simple and functionalized alcohols, without isomerisation of chiral centres. Changes of hydroxyl protective groups are possible in a one-pot procedure. The catalyst can be easily recycled.
- Dalpozzo, Renato,De Nino, Antonio,Maiuolo, Loredana,Procopio, Antonio,Nardi, Monica,Bartoli, Giuseppe,Romeo, Roberto
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p. 5621 - 5624
(2007/10/03)
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- Simple and efficient chemoselective mild deprotection of acetals and ketals using cerium(III) triflate
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A new and chemoselective method for the cleavage of alkyl and cyclic acetals and ketals at room temperature in wet nitromethane by using catalytic cerium(III) trifluoromethane sulfonate is presented. The high yields, the observed selectivity, the very gentle reaction conditions, and the almost neutral pH make this procedure particularly attractive for multistep synthesis.
- Dalpozzo, Renato,De Nino, Antonio,Maiuolo, Loredana,Procopio, Antonio,Tagarelli, Antonio,Sindona, Giovanni,Bartoli, Giuseppe
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p. 9093 - 9095
(2007/10/03)
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- Oxidation of bicyclic oxazolines: Applications to glycomimetics and novel saccharide derivatives
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A general procedure is reported for the oxidation of substituted oxazolines to α-acyloxyketoximes and the derived α-acyloxyketones. In the case of oxazolines derived from 2-acetamido-2-deoxyhexoses, the resulting 2-oximinoesters can be converted to 2-nitr
- Clark, Matthew A,Wang, Qunzhao,Ganem, Bruce
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p. 347 - 349
(2007/10/03)
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- Synthesis of α-acetoxy and formyloxy ketones by thallium(III) promoted α-oxidation
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Treatment of ketones with thallium(III) triflate in amide solvents at 60°C for 30 min followed by addition of small amounts of H2O cleanly provided the corresponding α-acyloxy ketones.
- Lee,Jin,Choi
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p. 956 - 957
(2007/10/03)
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- An efficient synthesis of α-acyloxyketone by Cu(acac)2-catalyzed insertion reaction of α-diazoketone to carboxylic acid
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An efficient insertion reaction of α-diazoketone to various carboxylic acids was achieved by using Cu(acac)2 as a catalyst. Treatment of the diazo compound with a carboxylic acid (1.2 equiv) in the presence of Cu(acac)2 (0.1 equiv) at room temperature afforded the corresponding ketoester in good yield. Various kinds of functional groups were tolerated under the reaction conditions.
- Shinada, Tetsuro,Kawakami, Tadashi,Sakai, Hiroshi,Takada, Ichinori,Ohfune, Yasufumi
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p. 3757 - 3760
(2007/10/03)
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- Diastereo- and enantioselective synthesis of cis-2- hydroxycyclohexanamine and corresponding ethers by asymmetric reductive amination
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A series of homochiral cis-2-alkoxy- and 2-aryloxyeyclohexanamines 5b- 5e has been synthesised by means of asymmetric reductive amination of the corresponding racemic 2-oxygenated cyclohexanones 2 with ee-values ranging from 95 to >99%. The respective 2-hydroxy and 2-cyclohexyl derivatives 5g-5h have been prepared from the 2-phenoxycyclohexanamine 4e. Relative and absolute stereochemistry has been elucidated.
- Lauktien, Gerhard,Volk, Franz-J,Frahm, August W.
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p. 3457 - 3466
(2007/10/03)
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- Ring-Chain Tautomerism Provides a Route to 7a-Hydroxy-3a-methyl-2,7-dioxoperhydrobenzofuran. Synthesis of the Hydroxy γ-Lactone Substructure of Myrocin and Other Bioactive Natural Products
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(2-Oxocyclohexyl)acetic acid 10 was converted into bicyclic alkoxy γ-lactones 12a-d via intermediate chloro lactone 11 and alkanolysis.Similarly, lactones 15a,b and 18 were prepared.In contrast, simple ring-chain tautomerism directly afforded the title heterocycle 28, a crystalline, stable and welldefined compound.The angular methyl group seems essential for the spontaneous lactonization. 5,5-Dialkoxy-4-oxocarboxylic acids 26a, b without an angular methyl group did not cyclize to bicyclic hydroxy γ-lactones. - Key Words: Hydroxy lactone, 5-membered, (lactol) tautomer / 4-Oxocarboxylic acids / Keto-cyclol tautomerism.
- Langschwager, Wolf,Hoffmann, H. Martin R.
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p. 797 - 802
(2007/10/02)
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- A Novel Method for the Preparation of Acid-Sensitive Epoxides from Olefins with the Combined Use of Molecular Oxygen and Aldoacetal Catalyzed by a Cobalt(II) Complex
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An efficient synthesis of acid-sensitive epoxides, such as chromene oxide or epoxide of γ,δ-unsaturated alcohol, was successfully achieved by the oxygenation of corresponding olefins with the combined use of an atmospheric pressure of molecular oxygen and aldoacetal catalyzed by a cobalt(II) complex coordinated with the 1,3-diketone ligand.The reactions proceeded under mild and neutral conditions, and the desired epoxides were obtained in good yields.Neither overoxidation nor decomposition of the formed epoxide was observed under the present reaction conditions.Furthermore, various silyl enol ethers and silyl ketene acetals, acid-sensitive compounds, were also smoothly monooxygenated into the corresponding α-hydroxy ketones and α-hydroxy carboxylic acid esters, respectively.
- Yorozu, Kiyotaka,Takai, Toshihiro,Yamada, Tohru,Mukaiyama, Teruaki
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p. 2195 - 2202
(2007/10/02)
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- Epoxidation of Olefinic Compounds with Combined Use of Molecular Oxygen and Propionaldehyde Diethyl Acetal Catalyzed by Cobalt(II) Complex. Efficient Method for the Preparation of Acid-sensitive Epoxides
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Synthesis of acid-sensitive epoxides such as epoxide of bishomoallyl alcohol or chromene oxide was achieved by the epoxidation of corresponding olefins with combined use of molecular oxygen and propionaldehyde diethyl acetal catalyzed by cobalt(II) comple
- Yorozu, Kiyotaka,Takai, Toshihiro,Yamada, Tohru,Mukaiyama, Teruaki
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p. 1579 - 1582
(2007/10/02)
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- Thermal Isomerization of a Vinylcyclobutene to a Cyclohexadiene
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Above 100 deg C 5-methylenespironon-1-ene, 1, undergoes cyclobutene ring opening to (E)-triene 2 and apparent 1,3-shift to a hexahydronaphthalene, 3, in a 3 to 1 ratio. (E)-triene 2 gives 3 in a competitive reaction.The activation energies for all th
- Paul, Gitendra C.,Gajewski, Joseph J.
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p. 1970 - 1973
(2007/10/02)
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- Chemistry of Dioxiranes. 21. Thermal Reactions of Dioxiranes
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Thermolysis of dioxiranes in solutions of their parent ketones or in mixtures of the parent ketone and a foreign ketone leads to the formation of esters.The results are explained by postulating a free-radical mechanism involving H atom abstraction from the ketones.The resulting radicals are converted to the observed esters by reaction with acyloxy radicals derived from homolysis of the dioxiranes.Autodecomposition of dimethyldioxirane in acetone solution at room temperature gives methyl acetate at a very slow rate.When catalyzed by BF3 etherate the same decomposition proceeds much more rapidly and is accompanied by acetol formation.
- Singh, Megh,Murray, Robert W.
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p. 4263 - 4270
(2007/10/02)
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- Indirect Electrooxidation of Alcohols by a Double Mediatory System with Two Redox Couples of +=O>/R2NO. and . or Br+>/Br- in an Organic-Aqueous Two-Phase Solution
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An indirect electrooxidation method for alcohol to aldehyde or ketone conversion has been developed.This method, applicable to chemoselective oxidation, employs two redox couples, consisting of 2,2,6,6-tetramethylpiperidine-1-oxyl derivatives 6 and active bromine species.The former is required for the chemical process and recycled, whereas the latter is to be involved in the electrochemical process.Three chemical events play an important role in this system: (1) the formation of . or Br+> from bromide ion by discharge on the anode in an aqueous solution, (2) the reaction of N-oxyl compounds 6 with active bromine species to generate N-oxoammonium ion 7, and (3) the oxidation of alcohols with 7 in an organic phase.Optimum conditions were established as follows: an aqueous 25percent NaBr solution buffered at pH 8.6 in a binary system, the use of 1-10 mol percent of 4-(benzoyloxy)piperidine derivatives 6, and adjustment of an electric current at 10-100 mA/cm2.The successful applications of the present method to the oxidation of a variety of primary and secondary alcohols including 1,n-diols, giving the corresponding carbonyl compounds, have delineated its synthetic utility.The chemoselective oxidation of a primary hydroxy group in the presence of secondary one has been achieved with a high selectivity by the present procedure.
- Inokuchi, Tsutomu,Matsumoto, Sigeaki,Torii, Sigeru
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p. 2416 - 2421
(2007/10/02)
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- A Selective and Efficient Method for Alcohol Oxidations Mediated by N-Oxoammonium Salts in Combination with Sodium Bromite
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The oxidation of primary and secondary alcohols leading to aldehydes, carboxylic acids, and ketones has been carried out in a N-oxoammonium salts-NaBrO2 system.Sodium bromite as a stoichiometric oxidizing reagent activates N-oxyl compounds (recycling catalysts) to their N-oxoammonium salts in a weakly basic medium, which oxidize primary hydroxyl groups preferentially rather than secondary ones to the corresponding aldehydes.Calcium hypochlorite is used as an alternative terminal oxidant in the same media.The procedure, applicable to the selective formation of γ- and δ-lactones, β-hydroxy aldehydes, and 2-acetoxy ketones, is advantageous in terms of reagent cost, safety, and ease of operation.
- Inokuchi, Tsutomo,Matsumoto, Sigeaki,Nishiyama, Tokio,Torii, Sigeru
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p. 462 - 466
(2007/10/02)
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- OXIDATIVE ACETOXYLATION OF THE SILYL ETHERS OF KETONE ENOLS
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The reaction of (diacetoxyiodo)benzene with the trimethylsilyl ethers of ketone enols takes place with retention of the (CH3)3Si group in two directions, i.e., substitution of the vinylic hydrogen or diacetoxylation of the double bond.The reaction can be
- Brunovlenskaya, I. I.,Kusainova, K. M.,Kashin, A. K.
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p. 316 - 320
(2007/10/02)
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- OXIDATION OF 1-ACETOXYCYCLOHEXENE CATALYZED BY VO2 + , MoO22 + , AND Cr3 ACETYLACETONATES.
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We studied the possibility of obtaining acetoxyketones more selectively during catalytic oxidation of ACH-1 (1-Acetoxycyclohexene) in the presence of metal compounds of varying valence: vanadyl, molybdenyl, chromium, and chromium stearate acetylacetonates, which have been shown to be effective catalysts for hydroperoxide decomposition and olefin epoxidation. It is shown that during oxidation of ACH-1 in the presence of MoO//2 (acac)//2, the concentration of ACHanone-2 (1-Acetoxycyclohexane-2-one) and CHenone-1 (2-Cyclohexene-1-one) increases. The increase in the relative content of these compounds is due primarily to a decrease in the amount of ACHenone-3 (1-Acetoxycyclohex-3-one). Moreover, at the same oxidation level, the concentration of ACHanone-2 is almost two times higher and that of HP two times lower than in the uncatalyzed oxidation.
- Gudimenko,Agabekov,Shibaeva,Mitskevich
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p. 1018 - 1021
(2007/10/02)
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- A Method for Mild Photochemical Oxidation; Conversion of Phenacyl Sulfides into Carbonyl Compounds
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Sunlamp irradiation of phenacyl sulfides PhCOCH2SCHRR' affords thiocarbonyl compounds S=CRR' that can be trapped in high yield by using the nitronate CH3CH=N+(OTBS)O-; the heterocycle 3 resulting from 1,3-dipolar cycloaddition is cleaved rapidly by fluoride ion to give ketones or aldehydes.
- Vedejs, E.,Perry, D. A.
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p. 573 - 575
(2007/10/02)
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- BAEYER-VILLIGER OXIDATION WITH Me3SiOOSiMe3 UNDER ASSISTANCE OF SnCl4 OR BF3-OEt2.
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Treatment of ketones with bis(trimethylsilyl) peroxide and Lewis acid such as SnCl//4 or BF//3-OEt//2 in dichloromethane at room temperature affords esters in fair to excellent yields. Jasmine lactone is synthesized from 2- left bracket (Z)-pentenyl right bracket cyclopentanine by means of Me//3SiOOSiMe//3-BF//3-OEt//2 system without any protection of the carbon-carbon double bond. The oxidation of enol acetates of ketones to alpha -hydroxy (or alpha -acetoxy) ketones with Me//3SiOOSiMe//3-FeCl//3 system is also disclosed.
- Matsubara,Takai,Nozaki
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p. 2029 - 2032
(2007/10/02)
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- α-Oxygenation of Aldehydes and Cyclic Ketones by Acylation-Rearrangement of Nitrones
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The reaction of N-tert-butylnitrones (1a-e) of aldehydes and N-methylnitrones (2 and 3) of cyclic ketones with acid chlorides in the presence of triethylamine afforded α-acyloxy imines by rearrangement of N-vinyl-O-acylhydroxylamine intermediates.Hydrolysis of the α-acyloxy imines gave α-acyloxy aldehydes and ketones.The acylation-rearrangement reaction offers a new method for α-oxygenation of carbonyl compounds.
- Cummins, Clark H.,Coates, Robert M.
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p. 2070 - 2076
(2007/10/02)
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- Use of Tellurium(IV) and Tellurium(VI) as Oxidants in Organic Synthesis
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The oxidizing properties of TeO2, Te(OH)6, and TeO3 in acetic acid solution containing LiBr have been explored.It was found that certain aromatic compounds were acetoxymethylated by the action of TeO2 or, when especially activated, converted into diarylmethane derivatives.Te(OH)6 and TeO3, in contrast, mainly effected side-chain acetoxylation, as was also the case with SeO2.In the acetoxymethylation reaction TeO2 apparently slowly oxidized the solvent, HOAc, to a reactive species of some kind, e.g., acetoxycarbene, which attacked the aromatic compound.In the side-chain acetoxylations, Te(VI) oxidized bromide ions to Br2, which caused benzylic bromination.The solvolysis of benzylic bromides to acetates was significantly enhanced by the presence of Te(IV) species.Both TeO2 and TeO3 effected more conventional oxidations like the transformation of deoxybenzil to benzil.Benzoin acetate is a probable intermediate in this oxidation.
- Bergman, Jan,Engman, Lars
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p. 5191 - 5196
(2007/10/02)
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- REACTIVITY OF ORGANOTIN COMPOUNDS. XXIII. REACTION OF LEAD TETRAACETATE WITH TRIETHYLSTANNYL AND TRIMETHYLSILYL ETHERS OF THE ENOLS OF CYCLIC KETONES AS A METHOD FOR THE PRODUCTION OF 2-ACETOXY KETONES
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The reactions of 1-cyclohexenyloxytriethyltin with lead tetraacetate and (diacetoxyiodo)benzene and the reaction of the trimethylsilyl ethers of the enols of cyclopentanone, cyclohexanone, 2-methylcyclohexanone (2-methyl-1-cyclohexenyloxytrimethylsilane and 6-methyl-1-cyclohexenyloxytrimethylsilane), cholestan-3-one, dl-camphor, and 1-methone with lead tetraacetate at room temperature in methylene chloride were investigated.The reaction of 1-cyclohexenyloxytriethyltin with lead tetraacetate and (diacetoxyiodo)benzene leads to the formation of 2-acetoxycyclohexanone and 2,2'-dioxo-1,1'-bicyclohexyl. 1-Cyclohexenyloxytrimethylsilane reacts with lead tetraacetate, giving (1,2-diacetoxycyclohexyloxy)trimethylsilane and (2-acetoxy-1-cyclo-hexenyloxy)trimethylsilane.As a result of the reactions of the trimethylsilyl ethers of the ketone enols with lead tetraacetate after treatment with BF3Et2O the corresponding 2-acetoxy ketones are obtained.The reaction mechanisms are discussed.
- Kashin, A. N.,Tul'chinskii, M. L.,Bumagin, N. A.,Beletskaya, I. P.,Reutov, O. A.
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p. 1390 - 1395
(2007/10/02)
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- The Chemistry of Aryllead(IV) Tricarboxylates. Reaction with Enamines
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The treatment of 1-morhpholinocyclopentene (1a) with p-methoxyphenyllead triacetate (2a) in chloroform provides a simple high-yielding route to 2-(4-methoxyphenyl)cyclopentanone (3a).This arylation reaction of enamines has been investigated with a variety of substrates and a number of aryllead triacetates.The reaction has been found to be very sensitive to steric effects and is thus a useful synthetic method in a relatively small number of cases.Acetoxylation is a major competing reaction with those enamines of cyclic ketones which give a low to moderate yield of arylated product.
- May, George L.,Pinhey, John T.
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p. 1859 - 1871
(2007/10/02)
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- Reaction of Enol Silyl Ethers with Silver Carboxylate-Iodine. Synthesis of α-Acyloxy Carbonyl Compounds
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The sequential treatment of enol silyl ethers with silver carboxylate-iodine (2:1) and then fluoride affords high yields of the corresponding α-acyloxy carbonyl compounds.Thus a wide range of variation is now possible for the acyloxy portion of the molecu
- Rubottom, George M.,Mott, Robert C.,Juve, Henrik D.
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p. 2717 - 2721
(2007/10/02)
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