- Laboratory evaluation of natural and synthetic aromatic compounds as potential attractants for male mediterranean fruit fly, ceratitis capitata
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Ceratitis capitata, the Mediterranean fruit fly, is one of the most serious agricultural pests worldwide responsible for significant reduction in fruit and vegetable yields. Eradication is expensive and often not feasible. Current control methods include
- Tabanca, Nurhayat,Masi, Marco,Epsky, Nancy D.,Nocera, Paola,Cimmino, Alessio,Kendra, Paul E.,Niogret, Jerome,Evidente, Antonio
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Read Online
- Domino Processes of Arynes Reacting with Three Classes of Nucleophiles for Organic Syntheses
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Synthetic application of arynes is broadened by their reactions with neutral N-, S-, and O-containing nucleophiles to produce three types of compounds. Accordingly, 1,2-dihydroquinolines are synthesized from Schiff bases, alkynes, and arynes through a Diels-Alder reaction. Epoxides are prepared from thioethers and arynes along with aldehydes or ketones through a Johnson-Corey-Chaykovsky reaction. Phenolic ethers are produced from allyl ethers and arynes through a Claisen-type rearrangement. These target molecules, including natural products γ-asarone, asaricin, and a cholesteryl phenolic ether, are formed through reactions initiated by arynes. These new reactions share a prevailing feature of domino processes, which are carried out in a single flask and afford the desired products in good to high yields.
- Hwu, Jih Ru,Panja, Avijit,Gupta, Nitesh K.,Hu, Yu-Chen,Tan, Kui-Thong,Lin, Chun-Cheng,Hwang, Kuo-Chu,Hsu, Ming-Hua,Huang, Wen-Chieh,Tsay, Shwu-Chen
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p. 683 - 693
(2021/01/18)
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- Synthesis and in vitro growth inhibition of 2-allylphenol derivatives against Phythopthora cinnamomi rands
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Phytophthora cinnamomi is a phytopathogen that causes extensive damage in different crops, and therefore, produces important economic losses all around the world. Chemical fungicides are a key factor for the control of this disease. However, ecological an
- Olea, Andrés F.,Espinoza, Luis,Sedan, Claudia,Thomas, Mario,Martínez, Rolando,Mellado, Marco,Carrasco, Héctor,Díaz, Katy
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- Palladium-catalyzed tandem isomerization/hydrothiolation of allylarenes
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Herein we report a tandem olefin migration/hydrothiolation of allyl benzenes facilitated by an in situ generated palladium hydride. A catalyst system composed of palladium acetate and bidentate ligand dtbpx (1,2-bis(di-tert-butylphosphinomethyl)benzene in the presence of catalytic amounts of triflic acid led to the tandem transformation, which furnished benzylic thioethers. The reaction exhibits high regioselectivity and can be conducted under mild conditions. The robustness of the catalyst is displayed through reactions with coordinating thiols.
- Kathe, Prasad M.,Fleischer, Ivana
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supporting information
p. 2213 - 2217
(2019/03/26)
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- Carbonylative Transformation of Allylarenes with CO Surrogates: Tunable Synthesis of 4-Arylbutanoic Acids, 2-Arylbutanoic Acids, and 4-Arylbutanals
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In this Communication, procedures for the selective synthesis of 4-arylbutanoic acids, 2-arylbutanoic acids, and 4-arylbutanals from the same allylbenzenes have been developed. With formic acid or TFBen as the CO surrogate, reactions proceed selectively and effectively under carbon monoxide gas-free conditions.
- Wu, Fu-Peng,Li, Da,Peng, Jin-Bao,Wu, Xiao-Feng
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supporting information
p. 5699 - 5703
(2019/08/01)
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- Palladium-Catalyzed meta-C-H Olefination of Arene-Tethered Diols Directed by Well-Designed Pyrimidine-Based Group
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The palladium-catalyzed meta-olefination of arene-tethered diols attached to a well-designed pyrimidine moiety is presented. Applications of the protocol are illustrated by the synthesis of various diol-based natural products, such as coumarins, phenylpropanoids, stilbenes, and chalcones. Advantages of this method are demonstrated through the easy removal of the template and a gram-scale olefination reaction. Finally, experimental verification, including 1H NMR, ESI-MS and IR, and DFT studies are undertaken to elucidate the mechanistic complexity.
- Fang, Siqiang,Wang, Xiaobing,Yin, Fucheng,Cai, Pei,Yang, Huali,Kong, Lingyi
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supporting information
(2019/03/19)
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- Synthesis and biological activity of novel phenol-conjugates of isoxazolidines
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1,3-Dipolar cycloadditions of the phosphonylnitrone with selected allylbenzenes produced mixtures of diastereoisomeric (3-diethoxyphosphoryl)isoxazolidines with good trans/cis diastereoselectivities (d.e. 80%) and good to excellent overall yields. No inhibitory activity against a broad panel of DNA and RNA viruses was detected for (3-diethoxyphosphoryl)isoxazolidines at 250 μM. Isoxazolidines trans-3k : cis-3k (95: 5) slightly reduced human embryonic lung (HEL) cell viability (CC50 = 45 μM). Four out of ten isoxazolidines inhibited the growth of Staphylococcus epidermidis ATCC 12228 (up to 40% for the most active compound). They were also inhibitory against Staphylococcus aureus ATCC 6538 although inhibition did not exceeded 25%. None of the isoxazolidines affected Escherichia coli ATCC 25922 and Pseudomonas aeruginosa ATCC 15442 growth.
- Piotrowska, Dorota G.,Wróblewski, Andrzej E.,Balzarini, Jan,Andrei, Graciela,Schols, Dominique,Snoeck, Robert,Felczak, Aleksandra,Wrońska, Natalia,Lisowska, Katarzyna,G?owacka, Iwona E.
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p. 1091 - 1100
(2017/08/01)
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- Cross-Coupling Reactions of Aryldiazonium Salts with Allylsilanes under Merged Gold/Visible-Light Photoredox Catalysis
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A method for the cross-coupling reactions of aryldiazonium salts with trialkylallylsilanes via merged gold/photoredox catalysis is described. The reaction is proposed to proceed through a photoredox-promoted generation of an electrophilic arylgold(III) intermediate that undergoes transmetalation with allyltrimethylsilane to form allylarenes.
- Akram, Manjur O.,Mali, Pramod S.,Patil, Nitin T.
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supporting information
p. 3075 - 3078
(2017/06/23)
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- Trifluoromethylchlorosulfonylation of alkenes: Evidence for an inner-sphere mechanism by a copper phenanthroline photoredox catalyst
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Abstract A visible-light-mediated procedure for the unprecedented trifluoromethylchlorosulfonylation of unactivated alkenes is presented. It uses [Cu(dap)2]Cl as catalyst, and contrasts with [Ru(bpy)3]Cl2, [Ir(ppy)2(dtbbpy)]PF6, or eosin Y that exclusively give rise to trifluoromethylchlorination of the same alkenes. It is assumed that [Cu(dap)2]Cl plays a dual role, that is, acting both as an electron transfer reagent as well as coordinating the reactants in the bond forming processes. Double role: The trifluoromethylchlorosulfonylation of unactivated alkenes was developed using [Cu(dap)2]Cl as catalyst (dap=2,9-bis(para-anisyl)-1,10-phenanthroline). [Cu(dap)2]Cl plays a dual role; acting as an electron transfer reagent as well as coordinating the reactants in the bond forming processes.
- Bagal, Dattatraya B.,Kachkovskyi, Georgiy,Knorn, Matthias,Rawner, Thomas,Bhanage, Bhalchandra M.,Reiser, Oliver
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supporting information
p. 6999 - 7002
(2015/06/08)
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- A facile and convenient sequential homobimetallic catalytic approach towards β-methylstyrenes. A one-pot Stille cross-coupling/isomerization strategy
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An efficient one-pot synthetic approach towards β-methylstyrenes is reported. The transformation, based on sequential homobimetallic catalysis, involves a Stille cross-coupling reaction between aryl halides and allyltributylstannane, followed by an in situ palladium-catalyzed conjugative isomerization. The reaction was optimized, and the best results were obtained with 10 mol% Pd(PPh3)2Cl2, 8.0 equiv. LiCl, and 0.5 equiv. PPh3 in diglyme at 130 °C for 12 h. It was demonstrated that the reaction tolerates a wide variety of functional groups. This journal is the Partner Organisations 2014.
- Simonetti, Sebastian O.,Larghi, Enrique L.,Kaufman, Teodoro S.
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p. 3735 - 3743
(2014/06/09)
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- Method for Allylating and Vinylating Aryl, Heteroaryl, Alkyl, and Alkene Halogenides Using Transition Metal Catalysis
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What is described is a process for preparing organic compounds of the general formula (I) R—R′??(I) by converting a corresponding compound of the general formula (II) R—X ??(II) in which X is fluorine, chlorine, bromine or iodine to an organomagnesium compound of the general formula (III) [M+]n[RmMgXkY1]??(III) wherein compounds of the formula (III) are reacted with a compound of the general formula (IV) characterized in that the reaction of (III) with (IV) is performed in the presence of a) catalytic amounts of an iron compound, based on the compound of the general formula (II), and optionally in the presence of b) a nitrogen-, oxygen- and/or phosphorus-containing additive in a catalytic or stoichiometric amount, based on the compound of the general formula (II).
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Paragraph 0062; 0063
(2013/07/25)
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- Isomerizing ethenolysis as an efficient strategy for styrene synthesis
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A shrinking chain: A bimetallic system consisting of [{Pd(μ-Br)(tBu 3P)}2] and a ruthenium metathesis catalyst has been found to efficiently promote the cross-metathesis between substituted alkenes and ethylene, while continuously migrating the double bond along the alkenyl chain (see scheme). When alkenylarenes, such as the natural products eugenol, safrol, or estragol, were treated with this catalyst under an ethylene atmosphere, they were cleanly converted into the corresponding styrenes and propylene gas. Copyright
- Baader, Sabrina,Ohlmann, Dominik M.,Goossen, Lukas J.
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supporting information
p. 9807 - 9810
(2013/08/23)
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- Practical iron-catalyzed allylations of aryl grignard reagents
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An operationally simple iron-catalyzed reductive cross-coupling reaction between aryl halides and allyl electrophiles has been developed. The underlying domino process exhibits high versatility with respect to the allylic leaving group (acetate, tosylate, diethyl phosphate, methyl carbonate, trimethylsilanolate, methanethiolate, chloride, bromide) and high economic and environmental sustainability with respect to the catalyst system (0.2-5 mol% tris(acetylacetonato)iron(III), ligand-free) and reaction conditions (tetrahydrofuran, 0°C, 45 min).
- Mayer, Matthias,Czaplik, Waldemar M.,Von Wangelin, Axel Jacobi
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supporting information; experimental part
p. 2147 - 2152
(2010/12/18)
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- Synthesis of aryl alkyl ethers by alkylation of phenols with quaternary ammonium salts
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Phenolic compounds can be efficiently O-methylated with tetramethylammonium chloride in diglyme or polyethyleneglycol (PEG) at temperatures of 150-160 °C and in the presence of either K2CO3 or NaOH. When applying benzyl-trimethylammonium chloride as a reagent, the benzylation and methylation of phenols occurs, with the benzylation product always predominating. With allyl-substituted phenols as substrates and using NaOH as a base it was possible to achieve both the alkylation and the double-bond isomerization of the allyl group to obtain (E/Z)-propenyl-substituted methyl and benzyl aryl ethers in a single preparative step.
- Maras, Nenad,Polanc, Slovenko,Kocevar, Marijan
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experimental part
p. 29 - 36
(2010/09/05)
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- The attempted stereoselective synthesis of chiral 2,2′-biindoline
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The attempted first stereoselective synthesis of 2,2′-biindoline using a metathesis-Sharpless asymmetric dihydroxylation strategy results in the synthesis of the heterocycle in poor to modest stereoselectivity. Attempts to improve the ee by varying the he
- Gresser, Mary J.,Wales, Steven M.,Keller, Paul A.
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experimental part
p. 6965 - 6976
(2010/09/18)
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- Palladium-catalyzed allylic acyloxylation of terminal alkenes in the presence of a base
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"Chemical Equation Presentation" The efficiency and the selectivity of the Pd-catalyzed oxidation, in carboxylic acids, of terminal alkenes are strongly improved in the presence of a base. The methodology is particularly well adapted for the oxidation of homoallylic alcohols, for which the resulting acyloxylated products are obtained selectively as E-isomers in fair to good yields. 2010 American Chemical Society.
- Thiery, Emilie,Aouf, Chahinez,Belloy, Julien,Harakat, Dominique,Bras, Jean Le,Muzart, Jacques
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supporting information; experimental part
p. 1771 - 1774
(2010/05/01)
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- Deprotonative metalation of substituted aromatics using mixed lithium-cobalt combinations
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The deprotonation of anisole was attempted using different homo- and heteroleptic TMP/Bu mixed lithium-cobalt combinations. Using iodine to intercept the metalated anisole, an optimization of the reaction conditions showed that in THF at room temperature 2 equiv of base were required to suppress the formation of the corresponding 2,2′-dimer. The origin of the dimer was not identified, but its formation was favored with allyl bromide as electrophile. The metalated anisole was efficiently trapped using iodine, anisaldehyde, and chlorodiphenylphosphine, and moderately employing benzophenone, and benzoyl chloride. 1,2-, 1,3-, and 1,4-dimethoxybenzene were similarly converted regioselectively to the corresponding iodides. It was observed that 2-methoxy- and 2,6-dimethoxypyridine were more prone to dimerization than the corresponding benzenes when treated similarly. Involving ethyl benzoate in the metalation-iodination sequence showed that the method was not suitable to functionalize substrates bearing reactive functions.
- Dayaker, Gandrath,Chevallier, Floris,Gros, Philippe C.,Mongin, Florence
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experimental part
p. 8904 - 8910
(2011/01/04)
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- Deprotonative metalation of substituted benzenes and heteroaromatics using amino/alkyl mixed lithium-zinc combinations
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Different homoleptic and heteroleptic lithium-zinc combinations were prepared, and structural elements obtained on the basis of NMR spectroscopic experiments and DFT calculations. In light of their ability to metalate anisole, pathways were proposed to justify the synergy observed for some mixtures. The best basic mixtures were obtained either by combining ZnCl 2·TMEDA (TMEDA = N,N,N',N'tetramethylethylenediamine) with [Li(tmp)] (tmp = 2,2,6,6-tetramethylpiperidino; 3 equiv) or by replacing one of the tmp in the precedent mixture with an alkyl group. The reactivity of the aromatic lithium zincates supposedly formed was next studied, and proved to be substrate-, base-, and electrophile-dependent. The aromatic lithium zincates were finally involved in palladium-catalyzed cross-coupling reactions with aromatic chlorides and bromides.
- Snegaroff, Katia,Komagawa, Shinsuke,Chevallier, Floris,Gros, Philippe C.,Golhen, Stephane,Roisnel, Thierry,Uchiyama, Masanobu,Mongin, Florence
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experimental part
p. 8191 - 8201
(2010/09/11)
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- Deprotonative metalation of functionalized aromatics using mixed lithium-cadmium, lithium-indium, and lithium-zinc species
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In situ mixtures of CdCl2TMEDA (0.5 equiv; TMEDA = N,N,N',N'-tetramethylethylenediamine) or InCl3 (0.33 equiv) with [Li(tmp)] (tmp = 2,2,6,6-tetramethylpiperidino; 1.5 or 1.3 equiv, respectively) were compared with the previously described mixture of ZnCl2-TMEDA (0.5 equiv) and [Li(tmp)] (1.5 equiv) for their ability to deprotonate anisole, benzothiazole, and pyrimidine. [(tmp)3CdLi] proved to be the best base when used in tetrahydrofuran at room temperature, as demonstrated by subsequent trapping with iodine. The Cd-Li base then proved suitable for the metalation of a large range of aromatics including benzenes bearing reactive functional groups (CONEt2, CO2Me, CN, COPh) or heavy halogens (Br, I), and heterocycles (from the furan, thiophene, pyrrole, oxazole, thiazole, pyridine, and diazine series). Fivemembered heterocycles benefiting from doubly activated positions were similarly dideprotonated at room temperature. The aromatic lithium cadmates thus obtained were involved in palladium-catalyzed cross-coupling reactions or simply quenched with acid chlorides.
- Snegaroff, Katia,L'Helgoual'ch, Jean-Martial,Bentabed-Ababsa, Ghenia,Nguyen, Tan Tai,Chevallier, Floris,Yonehara, Mitsuhiro,Uchiyama, Masanobu,Derdour, Aicha,Mongin, Florence
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experimental part
p. 10280 - 10290
(2010/04/24)
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- Development of highly chemoselective bulky zincate complex, tBu 4ZnLi2: Design, structure, and practical applications in small-/macromolecular synthesis
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We present full details of the unique reactivities of the newly developed dianion-type bulky zincate, dilithium tetra-ferf-butylzincate (tBu 4ZnLi2). With this reagent, halogen-zinc exchange reaction of variously functionalized haloaromatics and anionic polymerization of N-isopropylacrylamide (NIPAm)/styrene with excellent chemoselectivity were realized. Halogen-zinc exchange reaction followed by electrophilic trapping with propargyl bromide provided a convenient route to functionalized phenylallenes, particularly those with electrophilic functional groups (such as cyano, amide and halogens). Spectral and computational studies of the structure in the gas and liquid phases indicated extraordinary stabilization of this dianion-type zincate by its bulky ligands.
- Furayama, Taniyuki,Yonehara, Mitsuhiro,Arimoto, Sho,Kobayashi, Minoru,Matsumoto, Yotaro,Uchiyama, Masanobu
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supporting information; experimental part
p. 10348 - 10356
(2009/10/10)
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- Cross-coupling of aromatic bromides with allylic silanolate salts
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The sodium salts of allyldimethylsilanol and 2-butenyldimethylsilanol undergo palladium-catalyzed cross-coupling with a wide variety of aryl bromides to afford allylated and crotylated arenes. The coupling of both silanolates required extensive optimization to deliver the expected products in high yields. The reaction of the allyldimethylsilanolate takes place at 85°C in 1,2-dimethoxyethane with allylpalladium chloride dimer (2.5 mol %) to afford 73-95% yields of the allylation products. Both electron-rich and sterically hindered bromides reacted smoothly, whereas electron-poor bromides cross-coupled in poor yield because of a secondary isomerization to the 1-propenyl isomer (and subsequent polymerization). The 2-butenyldimethylsilanolate (E/Z, 80:20) required additional optimization to maximize the formation of the branched (γ-substitution) product. A remarkable influence of added alkenes (dibenzylideneacetone and norbornadiene) led to good selectivities for electron-rich and electron-poor bromides in 40-83% yields. However, bromides containing coordinating groups (particularly in the ortho position) gave lower, and in one case even reversed, selectivity. Configurationally homogeneous (E)-silanolates gave slightly higher γ-selectivity than the pure (Z)-silanolates. A unified mechanistic picture involving initial γ-transmetalation followed by direct reductive elimination or σ-π isomerization can rationalize all of the observed trends.
- Denmark, Scott E.,Werner, Nathan S.
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supporting information; experimental part
p. 16382 - 16393
(2009/05/08)
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- Phosphazene base-promoted halogen-zinc exchange reaction of aryl iodides using diethylzinc
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The use of catalytic t-Bu-P4 base dramatically improved the performance of halogen-zinc exchange of aryl iodides, and the arylzinc derivatives were functionalized under copper-free reaction conditions. The Royal Society of Chemistry 2006.
- Ueno, Masahiro,Wheatley, Andrew E. H.,Kondo, Yoshinori
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p. 3549 - 3550
(2008/09/19)
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- Sodium dithionite initiated addition of 1-bromo-1-chloro-2,2,2-trifluoroethane to allylaromatics. Facile synthesis of conjugated dienes substituted with terminal CF3 group
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Sodium dithionite effectively promotes the addition of 1-bromo-1-chloro-2,2,2-trifluoroethane to the terminal double bond of allylbenzenes 1. The reactions proceeded in MeCN/H2O to give a 3:1 mole ratio of diastereoisomers of 1-(2-bromo-4-chloro-5,5,5-trifluoropentyl)benzenes 2 as the main products together with small amounts of its reductive debromination products 3. Total yields of 2 and 3 were dependent on the nature of the aromatic ring substituents in 1. Treatment of adducts 2 with DBU in refluxing hexanes resulted in double dehydrohalogenation affording, in good yields, conjugated dienes 4 (1,1,1-trifluoro-5-phenyl-2,4-pentadienes) terminated with the CF3 group at the one end and the phenyl group at the opposite end. These dienes were found to be sufficiently reactive to undergo Diels-Alder condensation with active dienophiles to give trifluoromethylated carbocycles. The reactions of CF3CHClBr with allylheterocycles were less successful and lead to low yields of mixtures of hardly separable compounds or to polymeric resins.
- Ignatowska, Jolanta,Dmowski, Wojciech
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p. 720 - 729
(2008/03/28)
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- Cobalt-catalyzed direct electrochemical cross-coupling between aryl or heteroaryl halides and allylic acetates or carbonates
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The electroreduction of a mixture of functionalized aromatic or heteroaromatic bromides or chlorides and allylic compounds such as acetates or carbonates in an electrochemical cell fitted with a sacrificial iron anode affords, in the presence of cobalt halide associated with pyridine as ligand in acetonitrile or DMF, the corresponding coupling product in good yields.
- Gomes, Paulo,Gosmini, Corinne,Perichon, Jacques
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p. 1142 - 1145
(2007/10/03)
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- Selective halogen - Magnesium exchange reaction via organomagnesium ate complex
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Halogen-magnesium exchange of various aryl halides is achieved with a magnesium ate complex at low temperatures. Tributylmagnesate (nBu3MgLi) induces facile iodine-magnesium exchange at -78 °C. Dibutylisopropylmagnesate (iPrnBu2MgLi) is more reactive than nBu3MgLi, and this reagent accomplishes selective bromine-magnesium exchange at -78 °C. This procedure is utilized for the preparation of various polyfunctionalized arylmagnesium species. The exchange of alkenyl halides using this method proceeds with retention of configuration of the double bond.
- Inoue,Kitagawa,Shinokubo,Oshima
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p. 4333 - 4339
(2007/10/03)
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- Diastereoselective intramolecular meta photocycloaddition of side-chain- substituted 5-(2-methoxyphenyl)pent-1-enes
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Irradiation of a series of 5-(2-methoxyphenyl)pent-1-enes substituted with a hydroxy or trimethylsilyloxy group at the α-, β-, or γ-position of the side-chain yields in all cases meta photocycloadducts, in which the configuration at the substituted carbon atom is mainly endo. This indicates that the diastereoselectivity originates from minimization of steric interactions between the side-chain substituent and the ortho-methoxy group at the arene unit. Hydrogen bonding does not seem to be involved. The introduction of the side-chain substituents also influences the regioselectivity of the addition: The linear to angular adduct ratios are significantly increased compared to the case of the parent compound.
- Timmermans, Johan L.,Wamelink, Marc P.,Lodder, Gerrit,Cornelisse, Jan
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p. 463 - 470
(2007/10/03)
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- Synthesis of β,β-Dichlorosulfides and Their Reactions with Thiols
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Reaction of allyl aryl ethers with sulfur dichloride at of reagents ratio 2:1 proceeds regioselectively with the formation of β,β-dichlorosulfides as the products of Markovnikoff and anti-Markovnikoff addition to the double bond of the allyl group, wherea
- Arkhipov,Romanova,Anisimov
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p. 530 - 533
(2007/10/03)
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- Photoelectron transfer induced decarboxylation of substituted carboxylic acids across a liquid/liquid interface
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Methylene blue photocatalyzed electron transfer reactions of some phenoxyacetic acid derivatives and N-phenylglycine across a liquid/liquid interface led to their efficient decarboxylation. Nanosecond laser flash photolysis studies of this process, in a reverse micellar system of Aerosol- OT (AOT)-benzene-water indicated that the liquid/liquid interface acts as a barrier in controlling the energy wasting back electron transfer. Intramolecular C-C bond forming reactions of these radicals were utilized for the synthesis of various chroman derivatives.
- Rajesh,Thanulingam,Das, Suresh
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p. 16817 - 16834
(2007/10/03)
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- Photochemical electron transfer across a liquid/liquid interface: Methylene Blue-sensitized decarboxylation of substituted carboxylic acids
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Methylene Blue photocatalyzed electron transfer reactions of some substituted carboxylic acids across the water/benzene interface lead to efficient decarboxylation of these acids and the utility of this procedure has been demonstrated by the synthesis of some dihydrobenzopyran and dihydrobenzofuran derivatives.
- Das, Suresh,Thanulingam,Rajesh,George
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p. 1337 - 1340
(2007/10/02)
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- Electrophilic allylation of arenes with in situ generated allyltriarylbismuthonium compound: The Bismuth-mediated polarity inversion of allylsilanes
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Reaction of triarylbismuth difluorides 1 with allyltrimethylsilane 2 in CH2Cl2 in the presence of BF3·OEt2 at low temperature generates allyltriarylbismuthonium compound 3 as a pale yellow solution, in which aromatic hydrocarbons and ethers, triphenylphosphine, dimethyl sulfide, p-toluenesulfinate, and thiophenol are all readily allylated to afford the corresponding allyl derivatives in moderate to good yields.
- Matano, Yoshihiro,Yoshimune, Masanori,Suzuki, Hitomi
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p. 7475 - 7478
(2007/10/02)
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- COPPER PROMOTED ALLYLATION OF PHENOLS
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Phenols can be allylated at an ortho-position by use of a mixture of anhydrous copper(II) perchlorate and copper metal powder.
- Baruah, Jubaraj B.
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p. 8509 - 8512
(2007/10/02)
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- Functional Selectivity in Friedel-Crafts Alkylations with Polyfunctional Reactants over Acid Zeolites
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The selective formation of allyl-substituted aromatics over acid zeolites by electrophilic substitution of the aromatics with allyl alcohols is reported.In contrast to the reaction in homogeneous phase with H2SO4, this primary product is stable and almost no consecutive reactions of allyl-substitued aromatics are observed.When allyl chloride (7) is used as alkylating agent, nearly no allyl-substituted aromatic is obtained.HCl, liberated during reaction easily isomerizes the double bond, enabling a fast consecutive reaction.This implies that functional selectivity,which is unachievable in homogeneous phase can be easily reached over microporous solid Broensted acids, provided no homogeneous acid is formed during reaction.The functional selectivity is attributed to the suppression of bimolecular side reactions and to the reduced isomerization rate of the double bond.For the electrophilic aromatic substitution, the turnover number of the acid site is about 120, confirming the true catalytic nature of this reaction.Deactivation of the catalyst is attributed to the oligomerization of an olefin, made upon hydride transfer to an allyl cation.
- Espeel, P. H.,Janssens, B.,Jacobs, P. A.
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p. 7688 - 7693
(2007/10/02)
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- Chavicol and Related Compounds as Nematocides
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In a search for nematocidal compounds from wild plant sources, chavicol and demethyleugenol were found from V. furcatum, and 4-vinylphenol was found from three Rosaceae species.These three compounds each contained both p-hydroxyphenyl and exo-methylene moieties, and several related compounds were prepared and tested for nematocidal activity.The results show that the hydroxyphenyl group was essential for the activity, while the aliphatic substituents on the benzene ring enhanced it.The strongest activity was found with 4-propenylphenol.
- Yoshizawa, Yuko,Kawaii, Satoru,Kanauchi, Masatoshi,Chida, Manami,Mizutani, Junya
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p. 1572 - 1574
(2007/10/02)
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- STRUCTURE-ACTIVITY RELATIONSHIPS OF PHENYLPROPANOIDS AS GROWTH INHIBITORS OF THE GREEN ALGA SELENASTRUM CAPRICORNUTUM
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Twenty-seven commercial or synthetic phenylpropanoids have been tested in broth against the unicellular alga Selenastrum capricornutum.The antialgal activity seems to be linked to the number as well as to the position of the methoxyl group in the molecule.A slight effect of the side chain substitution was also observed. Key Word Index - Selenastrum capricornutum; allelochemicals; phenylpropanoids.
- Greca, Marina Della,Monaco, Pietro,Pollio, Antonino,Previtera, Lucio
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p. 4119 - 4124
(2007/10/02)
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- New liposoluble unsaturated benzalmalonate derivatives and their use as absorbers for ultraviolet radiation in cosmetics
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The invention relates to an unsaturated benzalmalonate derivative of formula: STR1 in which: R1 and R2 denote a hydrogen atom, a hydroxyl, a trimethylsiloxy, a C1 -C6 straight or branched chain alkyl, C1/s
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- REACTION OF ALLYLTRIMETHYLSILANE WITH AN AROMATIC COMPOUND USING HYPERVALENT ORGANOIODINE COMPOUND: A NEW ALLYLATION OF AROMATIC COMPOUNDS
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New general method for the allylation of aromatic compounds from allyltrimethylsilane utilizing the combination of iodosylbenzene and BF3 OEt2 are described, which is based upon the umpolung of allyltrimethylsilane by way of cationic allylphenyliodonium (III) salt complex as an intermediate.
- Lee, Kilsung,Kim, Dae Young,Oh, Dong Young
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p. 667 - 668
(2007/10/02)
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- Iodine(III)-Mediated Allylaton of Aromatic Compounds and Alcohols Using Allylmetal (Group IVb) Compounds
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The reaction of allylmetal (group IVb) compounds with aromatic compounds and iodosylbenzene in the presence of BF3-Et2O afforded the corresponding allylation products.Allylation of alcohols was also carried out to give allyl ethers.The activation of iodosylbenzene by the coordination of BF3-Et2O was assumed to be one of the most important factors for the reaction.The involvement of the reactive allyliodine(III) compounds in these reactions is discussed.Keywords - hypervalent organoiodine compound, iodosylbenzene; allylsilane; allylgermane; allylstannane; allyliodine(III) compound
- Ochiai, Masahito,Fujita, Eiichi,Arimoto, Masao,Yamaguchi, Hideo
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- Umpolung of Reactivity of Allylsilane, Allylgermane, and Allylstannane: Allylation of Aromatic Compounds with Allylmetal and Allylthallium Bis(trifluoroacetate)
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A direct allylation of aromatic compounds using allylsilane, allylgermane, or allylstannane (1) and arylthallium bis(trifluoroacetate) has been developed.The actual transmetalation reagent for 1 in the reaction was proposed to be thallium (III) trifluoroacetate (2), which was proposed together with diarylthallium trifluoroacetate by the disproportionation of arylthallium bis(trifluoroacetate).Keywords-allylation of aromatic compound; allylsilane; allylgermane; allylstannane; arylthallium bis(trifluoroacetate)
- Ochiai, Masahito,Fujita, Eiichi,Arimoto, Masao,Yamaguchi, Hideo
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p. 3994 - 3999
(2007/10/02)
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- UMPOLUNG OF REACTIVITY OF ALLYLSILANE, ALLYLGERMANE, AND ALLYLSTANNANE VIA THEIR REACTION WITH THALLIUM (III) SALT: A NEW ALLYLATION REACTION FOR AROMATIC COMPOUND
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A new direct allylation of the aromatic compound has been developed.A combination of allylsilane, allylgermane, or allylstannane and thallium (III) trifluoroacetate gave rise to an allyl cationic species which was allowed to react with an aromatic compound, a nucleophile, to give allylation product(s) in good yields.
- Ochiai, Masahito,Arimoto, Masao,Fujita, Eiichi
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p. 4491 - 4494
(2007/10/02)
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