39831-53-3Relevant academic research and scientific papers
Spicing up olefin cross metathesis with the renewables estragole and methyl sorbate
Ferreira, Leonildo A.,Silva, Josiane T.,Alves, Raissa G.,Oliveira, Kelley C.B.,dos Santos, Eduardo N.
, (2021/05/03)
Diene moieties conjugated to a carbonyl group are ubiquitous in nature and are present in compounds with relevant biological properties. Herein we investigate the cross metathesis (CM) of the renewable cross partners estragole and methyl sorbate (MeSo) to produce methyl 6-(4-methoxyphenyl)hexa-2,4-dienoate. By the judicious choice of the ruthenium-based metathesis catalysts, as well as the reaction conditions, it was possible to obtain good conversion and selectivity for the desired product in catalyst loadings as low as 50 ppm (0.005 mol%), with a minimal amount of solvent.
Electrochemically Enabled, Nickel-Catalyzed Dehydroxylative Cross-Coupling of Alcohols with Aryl Halides
Li, Zijian,Sun, Wenxuan,Wang, Xianxu,Li, Luyang,Zhang, Yong,Li, Chao
supporting information, p. 3536 - 3543 (2021/03/08)
As alcohols are ubiquitous throughout chemical science, this functional group represents a highly attractive starting material for forging new C-C bonds. Here, we demonstrate that the combination of anodic preparation of the alkoxy triphenylphosphonium ion and nickel-catalyzed cathodic reductive cross-coupling provides an efficient method to construct C(sp2)-C(sp3) bonds, in which free alcohols and aryl bromides - both readily available chemicals - can be directly used as coupling partners. This nickel-catalyzed paired electrolysis reaction features a broad substrate scope bearing a wide gamut of functionalities, which was illustrated by the late-stage arylation of several structurally complex natural products and pharmaceuticals.
Practical iron-catalyzed allylations of aryl grignard reagents
Mayer, Matthias,Czaplik, Waldemar M.,Von Wangelin, Axel Jacobi
supporting information; experimental part, p. 2147 - 2152 (2010/12/18)
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).
Gas-phase pyrolytic reaction of 4-Aryl-3-buten-2-ols and allyl benzyl ethers: Kinetic and mechanistic study
Al-Etaibi, Alya M.,Al-Awadi, Nouria A.,Ibrahim, Maher R.,Ibrahim, Yehia A.
experimental part, p. 407 - 419 (2010/05/02)
Flash vacuum pyrolysis (FVP) of 4-aryl-3-buten-2-ols [ArCH=CHCH(CHs)OH, where Ar is phenyl, p-MeO, p-Me, p-Cl, p-NO2] gave the corresponding buta-1,3-dien-1-ylbenzene (ArCH=CH-CH=CH2, where Ar is Ph, p-MeO, p-Me, p-Cl, pNO2) and 7-×-1,2-dihydronaphthalene derivatives (where X is H, MeO); FVP of 1-aryl-3benzyloxyl-1-butenes and benzyl cinnamyl ethers [ArCH=CHCH(X)OCH2Ph, where Ar is phenyl, p-MeO, p-Me, p-Cl, X is H, Me, Ph] gave the corresponding but-2-en-l-ylbenzene derivatives (ArCH 2CH=CH-X, where X is H, Me, Ph) together with benzaldehyde. The proposed mechanism of these pyrolytic transformations was supported by kinetic and product analysis.
Cross-coupling of aromatic bromides with allylic silanolate salts
Denmark, Scott E.,Werner, Nathan S.
supporting information; experimental part, p. 16382 - 16393 (2009/05/08)
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.
Versatile friedel-crafts-type alkylation of benzene derivatives using a molybdenum complex/ortho-chloranil catalytic system
Yamamoto, Yoshihiko,Itonaga, Kouhei
experimental part, p. 10705 - 10715 (2009/12/01)
A variety of molybdenum complexes catalyze Friedel-Crafts-type alkylation reactions of benzene derivatives with alkenes and alcohols in the presence of an organic oxidant, o-chloranil. The utilization of [Mo(CO)6] and two equivalents of o-chloranil catalytically furnished the hydroarylation product of norbornene with p-xylene at 80°C, whereas [Cr(CO)6] and [W(CO)6] failed to catalyze the same reaction, thus indicating the importance of the molybdenum source. The best results were obtained when a molybdenum(II) complex [CpMoCl(CO)3] (Cp = cyclopentadienyl) was used as a precatalyst. The hydroarylation reactions also took place with styrenes, cyclohexenes, and 1 -hexene as olefin substrates. The electrophilic-substitution mechanism was proposed on the basis of the ortho/para selectivities and the Markovnikov selectivities observed for the hydroarylation products. Our hypothesis was further corroborated by the fact that in the presence of the [CpMoCl(CO)3]/o-chloranil catalytic system, secondary, benzylic, or allylic alcohols participated in the alkylation of benzenes with similar selectivities.
Hydrogen peroxide-or sodium hypochlorite-induced bromination of 1-arylbut-2-enes
Sadygov,Alimardanov
, p. 1661 - 1670 (2008/09/18)
Bromination of 1-arylbut-2-enes in the system [HBr or NaBr (KBr)-HX]-H 2O2 (or NaOCl) under relatively mild conditions leads to electrophilic addition of bromine or hypobromous acid at the side-chain double bond. Under more severe conditions, the process is accompanied by bromination of the aromatic ring. Treatment of the title compounds with peroxy acids (RCOOH-H2O2) gives the corresponding epoxy derivatives which react with HBr and oxygen-containing nucleophiles to produce α-bromo alcohols, diols, and diol acetates.
Preparation of olefins from alcohols by thermal rearrangement of propargylic xanthates
Faure-Tromeur, Melanie,Zard, Samir Z.
, p. 1305 - 1308 (2007/10/03)
Upon heating in toluene in the presence of a catalytic amount of collidinium trifluorosulfonate salt, various S-propargylic xanthates derived from secondary alcohols can be easily converted to their corresponding olefins in good yields.
