- Electronic Asymmetry of an Annelated Pyridyl-Mesoionic Carbene Scaffold: Application in Pd(II)-Catalyzed Wacker-Type Oxidation of Olefins
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The two donor modules of an annelated pyridyl-mesoionic carbene ligand (aPmic) have different σ- and π-bonding characteristics leading to its electronic asymmetry. A Pd(II) complex 1 featuring aPmic catalyzes the oxidation of a wide range of terminal olefins to the corresponding methyl ketones in good to excellent yields in acetonitrile. The catalytic reaction is proposed to proceed via syn-peroxypalladation and a subsequent rate-limiting 1,2-hydride shift, which is supported by kinetic studies. The electronic asymmetry of aPmic renders a well-defined coordination sphere at Pd. The favored arrangement of reactants on the metal center features an olefin trans to the pyridyl module and a tbutylperoxide trans to the carbene. This arrangement gains added stability by the π-delocalization paved by the compatible orbitals on Pd, the pyridyl module, and the olefin that is perpendicular to the Pd(aPmic) plane. The π-interactions are absent in an alternate arrangement wherein the olefin is trans to the carbene. Density functional theory studies reveal the matching orbital overlaps responsible for the preferred arrangement over the other. This work provides an orbital description for the electronic asymmetry of aPmic.
- Bera, Jitendra K.,Dutta, Indranil,Kunnikuruvan, Sooraj,Reshi, Noor U Din,Saha, Sayantani,Yadav, Suman
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p. 11385 - 11393
(2020/11/23)
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- 1,2-Diethoxyethane catalyzed oxidative cleavage of gem-disubstituted aromatic alkenes to ketones under minimal solvent conditions
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Aerobic oxidation using pure dioxygen gas as the oxidant has attracted much attention, but its application in synthetic chemistry has been significantly hampered by the complexity of catalytic system and potential risk of high-energy dioxygen gas. By employing 1,2-diethoxyethane as a catalyst and ambient air as an oxidant, an efficient protocol for the construction of various aryl-alkyl and diaryl ketones through oxidative cleavage of gem-disubstituted aromatic alkenes under minimal solvent conditions has been achieved.
- Liu, Kai-Jian,Deng, Ji-Hui,Zeng, Tang-Yu,Chen, Xin-Jie,Huang, Ying,Cao, Zhong,Lin, Ying-Wu,He, Wei-Min
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supporting information
p. 1868 - 1872
(2020/01/31)
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- Catalyst-Free Photodriven Reduction of α-Haloketones with Hantzsch Ester
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Catalyst-free dehalogenation of α-haloketones under visible light irradiation is studied. The reactions were carried out in common organic solvent. The outcomes of dechlorination are excellent in yields up to 92%, and it is also applicable to bromides, which give even higher yields. The reaction is tolerable to a broad spectrum of substrates, especially to aromatic ketones, including various aryl and hetaryl groups. There are two examples of aliphatic ketones presented in the paper, although their reactivities are not as high as that of the aromatic ketones.
- Lu, Zheng,Yang, Yong-Qing
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p. 508 - 515
(2019/01/10)
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- Visible light promoted copper-catalyzed Markovnikov hydration of alkynes at room temperature
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A new and efficient method for the hydration of alkynes to the corresponding ketones was successfully developed. The hydration process proceeds smoothly at room temperature with 1% mol of CuCl as catalyst under visible light irradiation. This protocol is applicable to various alkynes, including aromatic alkynes, polycyclic aromatic and heterocyclic aromatic excellent regioselectivity in good to excellent yields.
- Niu, Teng-fei,Jiang, Ding-yun,Li, Si-yuan,Shu, Xing-ge,Li, Huan,Zhang, Ai-ling,Xu, Jia-yu,Ni, Bang-qing
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supporting information
p. 1156 - 1159
(2017/03/02)
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- P -Selective (sp2)-C-H functionalization for an acylation/alkylation reaction using organic photoredox catalysis
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p-Selective (sp2)-C-H functionalization of electron rich arenes has been achieved for acylation and alkylation reactions, respectively, with acyl/alkylselenides by organic photoredox catalysis involving an interesting mechanistic pathway.
- Pandey, Ganesh,Tiwari, Sandip Kumar,Singh, Bhawana,Vanka, Kumar,Jain, Shailja
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supporting information
p. 12337 - 12340
(2017/11/20)
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- Chemoselective Continuous Ru-Catalyzed Hydrogen-Transfer Oppenauer-Type Oxidation of Secondary Alcohols
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A continuous flow method for the selective oxidation of secondary alcohols is reported. The method is based on an Oppenauer-type ruthenium-catalyzed hydrogen-transfer process that uses acetone as both solvent and oxidant. The process utilizes a low loading (1 mol%) of the commercially available ruthenium catalyst [Ru(p-cymene)Cl2]2 and triethylamine as a base and can be successfully applied to a range of different substrates, with a good level of functional group tolerance.
- Labes, Ricardo,Battilocchio, Claudio,Mateos, Carlos,Cumming, Graham R.,De Frutos, Oscar,Rincón, Juan A.,Binder, Kellie,Ley, Steven V.
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supporting information
p. 1419 - 1422
(2017/09/23)
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- Introverted Phosphorus-Au Cavitands for Catalytic Use
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A preparative synthesis of an inwardly directed phosphoramidite-Au complex is described and a description of some of its catalytic performance. The molecular structure was determined by crystallographic analysis, which disclosed that the phosphoramidite ligand points “out” and places the complexed Au “in”. We investigated its catalytic activities and found that the inwardly directed Au is surrounded by three inert walls that provide new opportunities for supramolecular catalysis and study of reactive intermediates.
- Schramm, Michael P.,Kanaura, Mao,Ito, Kouhei,Ide, Masataka,Iwasawa, Tetsuo
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supporting information
p. 813 - 820
(2017/01/18)
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- The micro-flow field reactor Friedel-Crafts application of the catalyst in the reaction
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The invention discloses an application of a micro-flow field reactor in Friedel-Crafts reaction. An immobilized microchannel reactor is filled with nano iron oxide particles for catalysis of Friedel-Crafts acylation reaction of aromatic hydrocarbon and acetyl chloride, wherein the nano iron oxide particles are prepared by the following methods: dissolving an iron-containing inorganic matter with distilled water, respectively and simultaneously pumping a water solution of inorganic alkali and a water solution of the iron-containing inorganic matter into the immobilized microchannel reaction device; standing for 30 seconds to 1 minute, reacting at a room temperature, and centrifuging the reaction product; and washing and drying sediments, and then sintering in a muffle furnace at 500 DEG C for 2 hours. The immobilized microchannel reactor is filled with the nano iron oxide particles prepared by the method for catalysis of Friedel-Crafts acylation reaction of the aromatic hydrocarbon and acetyl chloride.
- -
-
Paragraph 0056-0060
(2017/02/24)
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- Metal free visible light driven oxidation of alcohols to carbonyl derivatives using 3,6-di(pyridin-2-yl)-1,2,4,5-tetrazine (pytz) as catalyst
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3,6-Di(pyridin-2-yl)-1,2,4,5-tetrazine (pytz) catalyzed oxidation of alcohols to the corresponding carbonyl compounds under visible light irradiation is described. This reaction occurs smoothly at room temperature and shows good tolerance of functional groups. It provides an alternative approach for the synthesis of alkyl and aryl aldehydes and ketones.
- Samanta, Suvendu,Biswas, Papu
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p. 84328 - 84333
(2015/10/28)
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- Direct catalytic cross-coupling of alkenyllithium compounds
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A catalytic method for the direct cross-coupling of alkenyllithium reagents with aryl and alkenyl halides is described. The use of a catalyst comprising Pd2(dba)3/XPhos allows for the stereoselective preparation of a wide variety of substituted alkenes in high yields under mild conditions. In addition (1-ethoxyvinyl)lithium can be efficiently converted into substituted vinyl ethers which, after hydrolysis, give readily access to the corresponding methyl ketones in a one pot procedure.
- Hornillos, Valentn,Giannerini, Massimo,Vila, Carlos,Faans-Mastral, Martn,Feringa, Ben L.
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p. 1394 - 1398
(2015/02/19)
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- Carbohydrate-appended tumor targeting iron(III) complexes showing photocytotoxicity in red light
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Glucose-appended photocytotoxic iron(III) complexes of a tridentate Schiff base phenolate ligand [Fe(bpyag)(L)](NO3) (1-3), where bpyag is N,N-bis(2-pyridylmethyl)-2-aminoethyl-β-d-glucopyranoside and H 2L is 3-(2-hydroxyphenylimino)-1-phenylbutan-1-one (H 2phap) in 1, 3-(2-hydroxyphenylimino)-9-anthrylbutan-1-one (H 2anap) in 2, and 3-(2-hydroxyphenylimino)-1-pyrenylbutan-1-one (H2pyap) in 3, were synthesized and characterized. The complex [Fe(dpma)(anap)](NO3) (4), having bis-(2-pyridylmethyl)benzylamine (dpma), in which the glucose moiety of bpyag is substituted by a phenyl group, was used as a control, and the complex [Fe(dpma)(anap)](PF6) (4a) was structurally characterized by X-ray crystallography. The structure shows a FeN4O2 core in a distorted octahedral geometry. The high-spin iron(III) complexes with magnetic moment value of ~5.9 μB showed a low-energy phenolate-to-Fe(III) charge-transfer (CT) absorption band as a shoulder near 500 nm with a tail extending to 700 nm and an irreversible Fe(III)-Fe(II) redox couple near -0.6 V versus saturated calomel electrode. The complexes are avid binders to calf thymus DNA and showed photocleavage of supercoiled pUC19 DNA in red (647 nm) and green (532 nm) light. Complexes 2 and 3 displayed significant photocytotoxicity in red light, with an IC50 value of ~20 μM in HeLa and HaCaT cells, and no significant toxicity in dark. The cell death is via an apoptotic pathway, by generation of reactive oxygen species. Preferential internalization of the carbohydrate-appended complexes 2 and 3 was evidenced in HeLa cells as compared to the control complex 4. A 5-fold increase in the cellular uptake was observed for the active complexes in HeLa cells. The photophysical properties of the complexes are rationalized from the density functional theory calculations.
- Basu, Uttara,Khan, Imran,Hussain, Akhtar,Gole, Bappaditya,Kondaiah, Paturu,Chakravarty, Akhil R.
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p. 2152 - 2162
(2014/03/21)
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- Hydration of aromatic terminal alkynes catalyzed by iron(III) sulfate hydrate under chlorine-free conditions
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The hydration of aromatic terminal alkynes performed in acetic acid in the presence of catalytic hydrate ironIII sulfate, Fe2(SO 4)3·nH2O (4-9 mol %), yields the derived aryl methyl ketones with good to excellent yields. Under comparable conditions (18 mol %, 95 C, 24 h), bifunctional substrates were transformed into the monoacetyl or the diacetyl derivatives, depending on the structure of the aromatic diyne. The reaction is compatible with aryl substituents of different nature and ring positions, including hydroxyl, carbonyl groups, and cumulated hydrocarbons. The soft character of the non nucleophilic sulfate anion allows for activation of the triple bond toward carbonoxygen bond formation in the Br?nsted acidic medium. The proposed protocol is based on readily available and non toxic materials, in the absence of chlorine atoms in either the solvent or the metal catalyst.
- Bassetti, Mauro,Ciceri, Samuele,Lancia, Federico,Pasquini, Chiara
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supporting information
p. 1608 - 1612
(2014/03/21)
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- Ultrasound assisted Friedel-Crafts acylation of aromatics using ferric sulphate as catalyst
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The use of ultrasound in the acylation reactions of various aromatics and polyaromatics with different acyl chlorides, in the presence of catalytic amount of ferric sulphate at room temperature, gives good yields of the respective ketones with a short reaction time. A facile and simple synthesis of various aromatic ketones using Friedel-Crafts acylation has been established from the corresponding acid chlorides and aromatic or polyaromatic compounds, respectively under mild reaction conditions with shorter reaction times (30-45 min) and in reasonable yields. This method offers the advantage of low cost and ease of purification of the products because of the small amount of ferric sulphate used in these reactions.
- Sridharan, Anandhi,Gopalakrishnan, Geetha
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scheme or table
p. 1192 - 1195
(2011/10/18)
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- Nano-sulfated titania (TiO2/SO2-4) as a new solid acid catalyst for Friedel-Crafts acylation and Beckman rearrangement in solvent-free conditions
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The present work describes a novel application of nano-sulfated titania (nano-ST) as a solid acid catalyst for Friedel-Crafts acylation and Beckmann rearrangement. A nano-ST catalyst has been synthesized and characterized using various techniques such as XRD, scanning electron morphology, transmission electron microscopy, FT-IR, measurement of the specific surface area by Brunauer-Emmett-Teller theory and thermal analysis. The influences of various reaction parameters such as reaction temperature, molar ratio of reactants, reaction time and solvent effects have been investigated. [image omitted].
- Hosseini-Sarvari, Mona,Safary, Ensieh
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experimental part
p. 463 - 473
(2012/06/16)
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- Friedel-crafts acylation of arenes with carboxylic acids using polystyrene-supported aluminum triflate
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Cross-linked polystyrene-supported aluminum triflate (Ps-Al(OTf) 3) has been shown to be a mild, efficient, and chemoselective heterogeneous Lewis acid catalyst for the acylation of aromatic compounds. The catalyst can be easily prepared from cheap starting materials, is stable (as a bench top catalyst) and is reusable.
- Boroujeni, Kaveh Parvanak,Parvanak, Kamran
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experimental part
p. 155 - 163
(2012/01/02)
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- Polystyrene supported Al(OTf)3: An environmentally friendly heterogeneous catalyst for Friedel-Crafts acylation of aromatic compounds
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Stable and non-hygroscopic polystyrene supported aluminium triflate (Ps-Al(OTf)3), which is prepared easily from cheap and commercially available compounds was found to be an environmentally friendly heterogeneous catalyst for Friedel-Crafts acylation of arenes using acid chlorides in the absence of solvent under mild reaction conditions. The catalyst can be reused up to five times after simple washing with dichloromethane.
- Boroujeni, Kaveh Parvanak
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experimental part
p. 3156 - 3158
(2012/05/20)
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- Catalytic Friedel-Crafts acylation and benzoylation of aromatic compounds using activated hematite as a novel heterogeneous catalyst
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Catalytic Friedel-Crafts acylation of benzene and unactivated benzenes such as chlorobenzene and nitrobenzene have been successfully carried out using activated hematite (α-Fe2O3) as a new, heterogeneous and green catalyst. Sonication of neat α-Fe2O3 in a water bath under air atmosphere at room temperature followed by heating at 200°C, dramatically increase the activity of α-Fe2O 3. With the catalyst loading as low as 5.0mol%, a wide variety of benzene derivatives were easily converted into the corresponding acylated products in a clean and high-yielding acylation reaction. It was found that the activated α-Fe2O3 could be efficiently recycled and reused several times by simple washing with ethyl acetate, this cannot be attained with most of the traditional catalysts. Copyright
- Sharghi, Hashem,Jokar, Mahboubeh,Doroodmand, Mohammad Mahdi,Khalifeh, Reza
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experimental part
p. 3031 - 3044
(2011/02/21)
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- Friedel-Crafts acylation of arenes with carboxylic acids using silica gel supported AlCl3
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Aromatic compounds react smoothly with carboxylic acids in the presence of silica gel supported aluminium trichloride to afford the corresponding ketones with high regioselectivity in high to excellent yields. The catalyst is stable (as a bench top catalyst) and can be easily recovered and reused without appreciable change in its efficiency. tuebitak.
- Parvanak Boroujeni, Kaveh
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experimental part
p. 621 - 630
(2010/11/04)
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- Reversible Friedel-Crafts acylations of anthracene: Rearrangements of acetylanthracenes
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Treatment of 1-acetylanthracene (1-AcAN) and 9-acetylanthracene (9-AcAN) with PPA at 80-120 °C leads to the nearly complete conversion of these isomers into 2-acetylanthracene (2-AcAN), an illustration of the Agranat-Gore rearrangement of polycyclic aromatic ketones (PAKs). Ab initio MP2/6-31(d) calculations predict the following order of stabilities: for O-complexes: 9-AcAN>1-AcAN>2-AcAN; for ketones: 2-AcAN>1-AcAN>9-AcAN; for O-protonated ketones: 2-AcAN>1-AcAN>9-AcAN. Thus, 9-AcAN is the kinetically controlled product, whereas 2-AcAN is the thermodynamically controlled product. No reverse rearrangements of 2-AcAN to either 9-AcAN or 1-AcAN and of 1-AcAN to 9-AcAN were observed. The results strengthen the pattern of reversibility in Friedel-Crafts acylations of PAHs.
- Mala'bi, Tahani,Pogodin, Sergey,Agranat, Israel
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experimental part
p. 237 - 241
(2010/04/23)
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- An efficient method for aromatic Friedel-Crafts acylation reactions
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Friedel-Crafts acylation of aromatic compounds was carried out using FeCl3-based ionic liquid. This liquid serves as an efficient media as well as a Lewis acid catalyst. The significant advantages of this methodology are excellent yields, short reaction times, mild reaction conditions, environmentally friendly method, simple work-up procedure, low cost, and easy preparation and handling of the catalyst. Copyright
- Khodaei, Mohammad Mehdi,Bahrami, Kiumars,Shahbazi, Fomeida
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p. 844 - 845
(2008/12/22)
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- Palladium-catalyzed enantioselective oxidation of chiral secondary alcohols: Access to both enantiomeric series
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(Chemical Equation Presented) Rapid resolution: A new catalyst system for the oxidative kinetic resolution of secondary alcohols leads to dramatic rate increases. This system allows the use of a diamine to provide access to either enantiomer of a range of alcohols with good selectivity factors (see scheme). This method has been applied to the formal total synthesis of (-)-amurensinine.
- Ebner, David C.,Trend, Raissa M.,Genet, Cedric,McGrath, Matthew J.,O'Brien, Peter,Stoltz, Brian M.
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scheme or table
p. 6367 - 6370
(2009/03/11)
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- Unusual inhibition effect of 1-(1-naphthyl)-1-methylethylhydroperoxide on the liquid-phase oxidation of isopropylarenes. GC-MS and theoretical studies of the thermal decomposition of 1-naphthyl- and 1-anthryl-1- methylethylhydroperoxides
-
All five possible 1-aryl-1methylethylhydroperoxides derived from naphthalene and anthracene were synthesized and their thermal decomposition in GC-MS conditions was investigated to explain the unusual inhibition effect of 1-(1-naphthyl)-1-methylethylhydroperoxide on the liquid-phase oxidation of isopropylarenes. 2-(1-Aryloxy)propenes were identified as the main decomposition products of 1-(1-naphthyl)-1-methylethylhydroperoride and 1-(1-anthryl)-1- methylethylhydroperoxide. The relatively unstable 2-aryloxypropenes have thus far never been described as thermal decomposition products of 1-aryl-1-methylethylhydroperoxides. The plausible mechanism of the formation of 2-(1-aryloxy)propenes was proposed on the basis of AM-1 calculations of the possible rearrangement paths of the alkoxy radicals derived from the investigated hydroperoxides. The mechanism explains the inhibition effect of 1-(1-naphthyl)-1-methylethylhydroperoxide on the oxidation of isopropylarenes.
- Mazurkiewicz, Roman,Zawadiak, Jan,Orlinska, Beata,Hefczyc, Barbara,Stec, Zbigniew,Grymel, Miroslawa,Fiedorow, Piotr,Koroniak, Henryk
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p. 289 - 295
(2012/12/22)
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- Acylation of naphthalenes and anthracene on sulfated zirconia
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Sulfated zirconia (SZ) exhibits a high catalytic performance in the benzoylation of 1-methoxynaphthalene. Therefore, it was used as heterogeneous catalyst in the acylation of methoxynaphthalenes, methylnaphthalenes, naphthalene, and anthracene with benzoic anhydride, benzoyl chloride, and acetic anhydride to synthesize aromatic ketones. The rate of product formation on SZ was dependent on the respective aromatic, on the solvent used, and on the ratio of aromatic to acylating agent.
- Deutsch,Prescott,Mueller,Kemnitz,Lieske
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p. 269 - 278
(2007/10/03)
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- Aluminum dodecatungstophosphate (AlPW12O40) as a non-hygroscopic Lewis acid catalyst for the efficient Friedel-Crafts acylation of aromatic compounds under solvent-less conditions
-
Stable and non-hygroscopic aluminum dodecatungstophosphate (AlPW 12O40), which is prepared easily from cheap and commercially available compounds was found to be an effective catalyst for Friedel-Crafts acylation reactions using carboxylic acids, acetic anhydride and benzoyl chloride in the absence of solvent under mild reaction conditions.
- Firouzabadi, Habib,Iranpoor, Nasser,Nowrouzi, Farhad
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p. 10843 - 10850
(2007/10/03)
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- Photochemical Reactions of α-Bromoacetylarenes Studied by Product Analysis and Laser Flash Photolysis
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The hydrogen abstraction reaction and rearrangement reaction of aroylmethyl radicals were studied by product analyses and transient absorption spectroscopies. The α-bromoacetylarenes examined in this study gave aroylmethyl radicals by C-Br bond cleavage u
- Suzuki, Toshiaki,Kaneko, Yuji,Ikegami, Masashi,Arai, Tatsuo
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p. 801 - 806
(2007/10/03)
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- Zinc Mediated Friedel-Crafts Acylation in Solvent-Free Conditions under Microwave Irradiation
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Zn powder is found to catalyze the Friedel-Crafts acylation of aromatic compounds with acyl halides efficiently under microwave irradiation in solvent-free conditions. Activated substrates undergo acylation predominantly at the para-position. The Zn powder can be re-used up to six times after simple washing with diethyl ether and dilute HCl.
- Paul, Satya,Nanda, Puja,Gupta, Rajive,Loupy, Andre
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p. 2877 - 2881
(2007/10/03)
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- Solvent-free Friedel-Crafts acylation of aromatic compounds with carboxylic acids in the presence of trifluoroacetic anhydride and aluminum dodecatungstophosphate
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The stable and non-hygroscopic aluminum dodecatungstophosphate (AlPW12O40), was found to be an effective catalyst (3 mol%) for the solvent-free Friedel-Crafts acylation of aromatic compounds with carboxylic acids in the presence of trifluoroacetic anhydride under mild reaction conditions.
- Firouzabadi, Habib,Iranpoor, Nasser,Nowrouzi, Farhad
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p. 5343 - 5345
(2007/10/03)
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- Mechanistic investigations in diastereoselective Diels-Alder additions of chiral 9-anthrylethanol derivatives
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The preparation and subsequent Diels-Alder addition reactions of chiral 9-functionalised anthracene derivatives have been investigated. 9-(1-Methoxyethyl)anthracene undergoes highly diastereoselective (>95:5) thermal and photoinduced Diels-Alder additions with maleic anhydride and N-methylmaleimide. The corresponding reactions of 1-anthracen-9-ylethanol occur with the reverse sense of selectivity for additions with maleic anhydride with a corresponding increase in the reaction rate. The origins of this selectivity have been proposed to lie in hydrogen-bonding effects. The stereochemical outcome of the Diels-Alder additions has been determined from single X-ray crystallography of adducts 5 and 7. Solvent effects on the diastereoselectivity of these reactions have also been observed.
- Atherton, J. C. Christian,Jones, Simon
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p. 2166 - 2173
(2007/10/03)
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- Highly diastereoselective photochemical Diels-Alder reactions: Towards the development of a photoactivated chiral auxiliary
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Photochemical Diels-Alder additions of maleic anhydride to a homochiral anthracene derivative occur with excellent diastereoselectivity (>95:5) and faster than the corresponding thermal reactions.
- Jones, Simon,Atherton
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p. 1117 - 1119
(2007/10/03)
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- A new OsO4-mediated carbon-carbon bond cleavage reaction leading to the formation of anthraquinone
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A new OsO4-mediated carbon-carbon bond cleavage reaction leading to the formation of anthraquinone was observed. The reaction goes through the dihydroxylated intermediate and is aided by the presence of pyridine.
- Gao, Shouhai,Wang, Wei,Wang, Binghe
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- Friedel-Crafts reactions in room temperature ionic liquids
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Friedel-Crafts reactions in the ionic liquid system 1-methyl-3-ethylimidazolium chloride-aluminium(III) chloride can be performed with excellent yields and selectivities, and in the case of anthracene, have been found to be reversible.
- Adams, Christopher J.,Earle, Martyn J.,Roberts, Glyn,Seddon, Kenneth R.
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p. 2097 - 2098
(2007/10/03)
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- Acylation of activated aromatic substrates under mild conditions with (RCO)2O/Me2S/BF3
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An efficient procedure for acylation and perfluoroacylation of activated aromatic substrates under mild conditions using the system (RCO)2O/Me2S/BF3 in CH2Cl2 is described. It is believed that dimethylacylsulfonium salts, RCOSMe2+RCO2BF3-, are the active acylating agents.
- Kiselyov, Alexander S.
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p. 4005 - 4008
(2007/10/02)
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- Electrogenerated acid catalyzed acylation of electron-rich aromatics
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The acylation of electron-rich aromatic compounds was achieved in good yields under very mild conditions using an electrogenerated acid catalyst. M(ClO4)n dissolved in an organic anhydride (optionally mixed with a polar aprotic solvent) is useful for the electrochemical transformation in a divided cell.
- Gatti, Norberto
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p. 3933 - 3936
(2007/10/02)
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- A NOVEL SYNTHESIS OF SELENOPHENES
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Reduction of α,α'-diketo selenides with a low-valent titanium reagent usually affords 3,4-dihydroxyselenolanes, from wich the corresponding selenophenes are obtained by acid-catalyzed dehydration.A surprising exception is the formation of 2,4-dihydroy-2,4-di-t-butylselenolane from bis(2-t-butyl-2-oxoethyl) selenide, the former being converted to 2,4-di-t-butylselenophene by acid treatment.
- Nakayama, Juzo,Murai, Fumito,Hoshino, Masamatsu,Ishii, Akihiko
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p. 1399 - 1400
(2007/10/02)
-