cas 5211-62-1, 2-Methoxyphenylacetone | Articles data

Articles about 5211-62-1Total 30 be found

Article title
Article abstract
Author
Journal number and time
Download

Palladium(II)-catalyzed aerobic dialkoxylation of styrenes: A profound influence of an o-phenol
We report a Pd(II)-catalyzed aerobic dialkoxylation of styrene derivatives that requires an o-phenol. Initial scope and preliminary mechanistic studies are presented in which the o-phenol is proposed to facilitate the formation of a quinone methide intermediate. Copyright
Schultz, Mitchell J.,Sigman, Matthew S.
p. 1460 - 1461
(2006)
Read Online

Markovnikov Wacker-Tsuji Oxidation of Allyl(hetero)arenes and Application in a One-Pot Photo-Metal-Biocatalytic Approach to Enantioenriched Amines and Alcohols
The Wacker-Tsuji aerobic oxidation of various allyl(hetero)arenes under photocatalytic conditions to form the corresponding methyl ketones is presented. By using a palladium complex [PdCl2(MeCN)2] and the photosensitizer [Acr-Mes]ClO4 in aqueous medium and at room temperature, and by simple irradiation with blue led light, the desired carbonyl compounds were synthesized with high conversions (>80%) and excellent selectivities (>90%). The key process was the transient formation of Pd nanoparticles that can activate oxygen, thus recycling the Pd(II) species necessary in the Wacker oxidative reaction. While light irradiation was strictly mandatory, the addition of the photocatalyst improved the reaction selectivity, due to the formation of the starting allyl(hetero)arene from some of the obtained by-products, thus entering back in the Wacker-Tsuji catalytic cycle. Once optimized, the oxidation reaction was combined in a one-pot two-step sequential protocol with an enzymatic transformation. Depending on the biocatalyst employed, i. e. an amine transaminase or an alcohol dehydrogenase, the corresponding (R)- and (S)-1-arylpropan-2-amines or 1-arylpropan-2-ols, respectively, could be synthesized in most cases with high yields (>70%) and in enantiopure form. Finally, an application of this photo-metal-biocatalytic strategy has been demonstrated in order to get access in a straightforward manner to selegiline, an anti-Parkinson drug. (Figure presented.).
Albarrán-Velo, Jesús,Gotor-Fernández, Vicente,Lavandera, Iván
p. 4096 - 4108
(2021/08/19)

Method for isomerizing cis-anethole by using catalyst
The invention discloses a method for isomerizing cis-anethole by using a catalyst in the technical field of anethole preparation. The method comprises the following steps: 1, heating cis-anethole to 95-110 DEG C; 2, adding sodium hydrogen sulfate into the heated cis-anethole to obtain a mixture, heating the mixture for 8-10 min until the temperature of the mixture is 155-200 DEG C, and keeping thetemperature of the mixture constant for 1-1.2 hours to obtain a reaction product, wherein the weight ratio of the sodium bisulfate to the cis-anethole before heating is (1-5): 100; 3, cooling the reaction product to room temperature, carrying out liquid separation treatment to obtain a mixed solution, adding a sodium carbonate solution into the mixed solution, carrying out an oscillation reactionfor 5-6 min to obtain a neutralization solution, and separating the neutralization solution to obtain an upper-layer trans-anethole mixed solution, wherein the weight ratio of the sodium carbonate solution to the cis-anethole is (1-1.2): 10. According to the scheme, sodium hydrogen sulfate is adopted as a catalyst, isomerization of cis-anethole can be achieved by heating and stirring for 1 h at the temperature of 150-200 DEG C in the presence of sodium hydrogen sulfate, use of rare metals such as rhodium chloride is avoided, and the cis-anethole isomerization cost is greatly reduced.
-
Paragraph 0017; 0018

(2020/09/23)

Bromomethyl Silicate: A Robust Methylene Transfer Reagent for Radical-Polar Crossover Cyclopropanation of Alkenes
A general protocol for visible-light-induced cyclopropanation of alkenes was developed with bromomethyl silicate as a methylene transfer reagent, offering a robust tool for accessing highly valuable cyclopropanes. In addition to α-aryl or methyl-substituted Michael acceptors and styrene derivatives, the unactivated 1,1-dialkyl ethylenes were also shown to be viable substrates. Apart from realizing the cyclopropanation of terminal alkenes, the methyl transfer reaction has been further demonstrated to be amenable to the internal olefins. The photocatalytic cyclopropanation of 1,3-bis(1-arylethenyl)benzenes was also achieved, giving polycyclopropane derivatives in excellent yields. With late-stage cyclopropanation as the key strategy, the synthetic utility of this transformation was also demonstrated by the total synthesis of LG100268.
Luo, Wenping,Fang, Yewen,Zhang, Li,Xu, Tianhang,Liu, Yongjun,Li, Yan,Jin, Xiaoping,Bao, Jiakan,Wu, Xiaodong,Zhang, Zongyong
supporting information
p. 1778 - 1781
(2020/03/11)

Iron powder and tin/tin chloride as new reducing agents of Meerwein arylation reaction with unexpected recycling to anilines
Simple and rapid route for Meerwein arylation reaction using iron powder or a mixture of tin/tin chloride has been developed. In the presence of iron powder, different aryl diazonium salts reacted with methyl vinyl ketone, acrylates, and isopropenyl acetate. Production of oximes was detected as the main product with acrylates or in a mixture with β-aryl methyl ketones in the case of methyl vinyl ketone. The in situ produced HNO2 from an excess of NaNO2/HCl was trapped by alkyl aryl radical to form oximes in the E configuration form. The presence of tin/tin chloride mixture in the reaction of the aryl diazonium salts with methyl vinyl ketone produced Michael products along with β-aryl methyl ketones. The predicted α-aryl methyl ketones from the reaction of isopropenyl acetate with the diazotized anilines were obtained using iron or tin/tin chloride mixture.
Abdelwahab, Ahmed B.,El-Sawy, Eslam R.,Kirsch, Gilbert
supporting information
p. 526 - 538
(2020/01/08)

Stereoselective Synthesis of 1-Arylpropan-2-amines from Allylbenzenes through a Wacker-Tsuji Oxidation-Biotransamination Sequential Process
Herein, a sequential and selective chemoenzymatic approach is described involving the metal-catalysed Wacker-Tsuji oxidation of allylbenzenes followed by the amine transaminase-catalysed biotransamination of the resulting 1-arylpropan-2-ones. Thus, a series of nine optically active 1-arylpropan-2-amines were obtained with good to very high conversions (74–92%) and excellent selectivities (>99% enantiomeric excess) in aqueous medium. The Wacker-Tsuji reaction has been exhaustively optimised searching for compatible conditions with the biotransamination experiments, using palladium(II) complexes as catalysts and iron(III) salts as terminal oxidants in aqueous media. The compatibility of palladium/iron systems for the chemical oxidation with commercially available and made in house amine transaminases was analysed, finding ideal conditions for the development of a general and stereoselective cascade sequence. Depending on the selectivity displayed by selected amine transaminase, it was possible to produce both 1-arylpropan-2-amines enantiomers under mild reaction conditions, compounds that present therapeutic properties or can be employed as synthetic intermediates of chiral drugs from the amphetamine family. (Figure presented.).
González-Martínez, Daniel,Gotor, Vicente,Gotor-Fernández, Vicente
p. 2582 - 2593
(2019/05/15)

Porphyrins as Photoredox Catalysts in Csp2-H Arylations: Batch and Continuous Flow Approaches
We have investigated both batch and continuous flow photoarylations of enol-acetates to yield different α-arylated aldehyde and ketone building blocks by using diazonium salts as the aryl-radical source. Different porphyrins were used as SET photocatalysts, and photophysical as well as electrochemical studies were performed to rationalize the photoredox properties and suggest mechanistic insights. Notably, the most electron-deficient porphyrin (meso-tetra(pentafluorophenyl)porphyrin) shows the best photoactivity as an electron donor in the triplet excited state, which was rationalized by the redox potentials of excited states and the turnover of the porphyrins in the photocatalytic cycle. A two-step continuous protocol and multigram-scale reactions are also presented revealing a robust, cost-competitive, and easy methodology, highlighting the significant potential of porphyrins as SET photocatalysts.
De Souza, Aline A. N.,Silva, Nathalia S.,Müller, Andressa V.,Polo, André S.,Brocksom, Timothy J.,De Oliveira, Kleber T.
p. 15077 - 15086
(2019/01/03)

Fluorine as a Traceless Directing Group for the Regiodivergent Synthesis of Indoles and Tryptophans
Despite ample evidence for the unique reactivity offered by hypervalent F-iodanes, mechanistic investigations fall far behind. In order to shed light on the unusual behavior of such F-reagents, we conducted computational and experimental studies on the chemodivergent transformation of styrenes. We identified the spirocyclic F-cyclopropane as the common intermediate for both the C,H-fluorination and C,H-amination pathways. The fate of this key compound is determined by the extent of cationic charge delocalization controlled by the N-substituents. Exploiting this phenomenon, a multitude of different transformations have become available, leading, i.e., to the regiodivergent synthesis of indoles and tryptophans.
Andries-Ulmer, Anna,Brunner, Christoph,Rehbein, Julia,Gulder, Tanja
supporting information
p. 13034 - 13041
(2018/09/27)

Salicylic Acid-Catalyzed Arylation of Enol Acetates with Anilines
α-Aryl ketones are both structure moieties commonly found in bioactive compounds and versatile synthetic intermediates for the preparation of drug-like molecules. An operationally simple and scalable protocol has been developed to prepare α-aryl ketones from readily available aromatic amines and enol acetates (or silyl enol ethers). This metal-free methodology features the use of salicylic acid as a convenient catalyst to promote the formation of aryl radicals from in-situ generated aryl diazonium salts, without demanding thermal or photochemical activation. The mild reaction conditions used are compatible with anilines substituted with diverse functionalities. Structural elaboration of some prepared α-aryl ketones was accomplished to illustrate their usefulness as building blocks. (Figure presented.).
Felipe-Blanco, Diego,Gonzalez-Gomez, Jose C.
supporting information
p. 2773 - 2778
(2018/07/29)

Carbazolyl phosphorus ligand as well as preparation method and application thereof
The invention is suitable for the technical fields of organic compounds and synthesis, and provides a carbazolyl phosphorus ligand as well as a preparation method and application thereof. The carbazolyl phosphorus ligand is one of a compound 1, a compound 2 and a compound 3 with structures shown by a formula 1, a formula 2 and a formula 3 (shown in the description) respectively, wherein R1 is phenyl or alkyl, R2, R3, R4, R5, R6, R7, R8 and R9 independently are one of hydrogen, C5-C10 alkyl, methoxyl, oxymethyl, ethyoxyl, phenyl, fluorine group, and pyridyl; and R2, R3, R4, and R5 cannot be hydrogen at the same time.
-
Paragraph 0167; 0168; 0169; 0170; 0171; 0172

(2017/07/04)

A convenient and efficient one-pot synthesis of arylacetones from (E)-3-aryl-2-methylacrylic acids by curtius rearrangement
A convenient and efficient method was developed for the synthesis of arylacetones from (E)-3-aryl-2-methylacrylic acids through a Curtius rearrangement. The Curtius rearrangement of (E)-3-aryl-2-methylacryloyl azides and subsequent hydrolysis proceeded at mild temperatures in a two-phase medium of carbon tetrachloride and water containing a catalytic amount of tetrabutylammonium bromide to give the corresponding derivatives in 82-93% yield.
He, Xin,Cao, Chong,Liang, Jingwei,Li, Xinyang,Zhang, Tingjian,Meng, Fanhao
p. 386 - 390
(2017/02/10)

Preparation of a highly congested carbazoyl-derived p,n-type phosphine ligand for acetone monoarylations
We report a newly developed carbazoyl-derived P,N-type phosphine ligand (L1) for the monoarylation of acetone with aryl chlorides. The proposed Pd(dba)2/L1 catalyst exhibited remarkable catalytic reactivity toward highly electron rich and sterically congested aryl chlorides, with catalyst loading as low as 0.1 mol % of Pd along with excellent chemoselectivity. A reaction rate study of the system using electronically diverse aryl chlorides determined the mechanisms regarding the rate-limiting steps in this reaction. The oxidative addition adduct of Pd-PhenCar-Phos with p-chlorotoluene showed the participation of N-Pd coordination in the metal complex. The isolated palladium complex C1 could be utilized as a precatalyst in the transformation and achieved performance comparable to that of the in situ generated palladium species.
Fu, Wai Chung,Zhou, Zhongyuan,Kwong, Fuk Yee
p. 1553 - 1558
(2016/06/09)

Direct Asymmetric Reductive Amination for the Synthesis of Chiral β-Arylamines
The highly efficient and direct asymmetric reductive amination of arylacetones catalyzed by an iridium complex for the preparation of enantiomerically pure β-arylamines is described. The monodentate phosphoramidite ligand exhibits superb reactivity (TONs of up to 20 000) and enantioselectivity (up to 99 % ee). Additives played important roles in this reductive coupling reaction. Asymmetric reductive coupling of a ketone and an amine is a straightforward and atom-economic approach for preparing optically enriched amines. The highly efficient and direct asymmetric reductive amination of arylacetones, catalyzed by an iridium complex, supplies enantiomerically pure β-arylamines. The new phosphoramidite ligands reported show superb reactivity and enantioselectivity in this reductive coupling. M.S.=molecular sieves, TFA=trifluoroacetic acid.
Huang, Haizhou,Liu, Xiaoyan,Zhou, Le,Chang, Mingxin,Zhang, Xumu
supporting information
p. 5309 - 5312
(2016/04/26)

Palladium-Catalyzed Mono-α-arylation of Acetone at Room Temperature
The first examples of acetone mono-α-arylation at room temperature are described, enabled by use of a [Pd(cinnamyl)Cl]2/JosiPhos catalyst system. (Hetero)aryl chloride, bromide, and iodide electrophiles featuring or lacking ortho-substitution, and comprising a range of functionalities (e.g., alkoxy, cyano, fluoro, trifluoromethyl, or alkenyl) and heteroaryl motifs (e.g., pyrrole, pyridine, isoquinoline, quinoline, quinaldine, (benzo)thiophene, benzothiazole, or benzodioxole) were successfully accommodated. Proof-of-principle experiments confirm that other (hetero)aryl methyl ketones can also be employed in such room temperature mono-α-arylations. The established substrate scope is the most extensive reported to date for acetone mono-α-arylation under any conditions, and more generally represents the first room temperature ketone mono-α-arylations employing a structurally diverse set of (hetero)aryl chlorides. Chill out: The first examples of acetone mono-α-arylation at room temperature are described. The substrate scope is the most extensive reported to date for acetone mono-α-arylation under any conditions, and represents the first room temperature ketone mono-α-arylations employing a diverse set of (hetero)aryl chlorides.
Macqueen, Preston M.,Chisholm, Alicia J.,Hargreaves, Breanna K. V.,Stradiotto, Mark
supporting information
p. 11006 - 11009
(2015/11/10)

DIALKYL(2-ALKOXY-6-AMINOPHENYL)PHOSPHINE, THE PREPARATION METHOD AND USE THEREOF
The present invention relates to the compound of dialkyl(2-alkoxy-6-aminophenyl)phosphine and the preparation method thereof and the application in the palladium catalyzed coupling reactions of aryl chloride and ketone. The dialkyl(2-alkoxy-6-aminophenyl)phosphine of the present invention could coordinate with the palladium catalyst to highly selectively activate the inert carbon-chlorine bond, and to catalyze direct arylation reaction in the α-position of ketones to produce corresponding coupling compounds. The preparation method of the present invention is a simple one-step method which produces the air-stable dialkyl(2-alkoxy-6-aminophenyl)phosphine. Compared with the synthetic routes of ligands to be used in the activation of carbon-chlorine bonds in the prior arts, the preparation method of the present invention has the advantages of short route and easy operation.
-
Paragraph 0077; 0078

(2014/10/29)

Zheda-phos for general α-monoarylation of acetone with aryl chlorides
A new, readily available, and air-stable monophosphine ligand, i.e., Zheda-Phos, has been developed for the general and highly effective palladium-catalyzed monoarylation of acetone with aryl chlorides. The reaction rate is of first-order dependence with the aryl chloride. Copyright
Li, Pengbin,Lue, Bo,Fu, Chunling,Ma, Shengming
supporting information
p. 1255 - 1259
(2013/06/27)

Palladium-catalyzed mono-α-arylation of acetone with aryl imidazolylsulfonates
Set the ace(tone): A palladium catalyst derived from the bidentate XantPhos ligand and Pd(OAc)2 has enabled broadly applicable mono-α-arylations of acetone to be performed with air- and moisture-stable aryl imidazolylsulfonates as most user-friendly electrophiles (see scheme). Copyright
Ackermann, Lutz,Mehta, Vaibhav P.
supporting information; experimental part
p. 10230 - 10233
(2012/09/22)

Advancing the mechanistic understanding of an enantioselective palladium-catalyzed alkene difunctionalization reaction
The mechanism of an enantioselective palladium-catalyzed alkene difunctionalization reaction has been investigated. Kinetic analysis provides evidence of turnover-limiting attack of a proposed quinone methide intermediate with MeOH and suggests that copper is involved in productive product formation, not just catalyst turnover. Through examination of substrate electronic effects, a Jaffe relationship was observed correlating rate to electronic perturbation at two positions of the substrate. Ligand effects were evaluated to provide evidence of rapid ligand exchange between palladium and copper as well as a correlation between ligand electronic nature and enantioselectivity.
Jensen, Katrina H.,Webb, Jonathan D.,Sigman, Matthew S.
scheme or table
p. 17471 - 17482
(2011/02/27)

Efficient synthesis of chiral β-arylisopropylamines by using catalytic asymmetric hydrogenation
(Chemical Equation Presented) Direct condensation of β-arylketones with acetamide afforded both Z and E enamides. The Z-configured substrates underwent hydrogenation with excellent enantioselectivity by using the Rh/tang-phos catalytic system (see scheme; tangphos = 1,1′-di-tert-butyl- [2,2′]-diphospholanyl). The product β-arylisopropylamines are important precursors to several drugs.
Chen, Jian,Zhang, Weicheng,Geng, Huiling,Li, Wei,Hou, Guohua,Lei, Aiwen,Zhang, Xumu
supporting information; experimental part
p. 800 - 802
(2009/05/06)

Development of a robust and practical process for the Darzens condensation and α,β-epoxide rearrangement: Scope and limitations of the methodology
A practical and robust process for the Darzens condensation of substituted benzaldehydes and subsequent α,β-epoxy rearrangement is reported. The process developed is both amenable to large scale and parallel synthesis. While electron-poor benzaldehydes gave mixtures of aryl ketones and 2-substituted aryl ketones in mediocre to low yields, electron-rich benzaldehydes were found to react in high yields with complete regioselectivity to form 2-substituted aryl ketones. Georg Thieme Verlag Stuttgart.
Zimbron, Jeremy Malcolm,Seeger-Weibel, Manuela,Hirt, Hans,Gallou, Fabrice
p. 1221 - 1226
(2008/12/22)

Mechanistic insights into the palladiumII-catalyzed hydroxyalkoxylation of 2-allylphenols
The Pd(OCOCF3)2/[(HOCH2CH 2NHCOCH2)2NCH2]2- catalyzed oxidation of o-allylphenol with H2O2 in water/methanol affords a syn and anti mixture of 2-(1,2-dihydroxypropyl)phenol and 2-(2-hydroxy-1-methoxypropyl)phenol. Mechanistic experiments and ESI-MS studies support a pathway wherein isomerization of the C=C bond followed by its epoxidation and oxirane opening led to the products. Recycling of the catalytic system led to gradual lost of activity.
Thiery, Emilie,Chevrin, Carole,Le Bras, Jean,Harakat, Dominique,Muzart, Jacques
p. 1859 - 1862
(2007/10/03)

Evidence that the availability of an allylic hydrogen governs the regioselectivity of the Wacker oxidation
The allylic hydrogen is found to have a dramatic effect on the regioselectivity of the Wacker oxidation, leading to the postulation that an agostic hydrogen or enyl (σ + π) complex helps to stabilise the key intermediate.
Gaunt,Yu,Spencer
p. 1844 - 1845
(2007/10/03)

Synthesis of benzofurans via Pd2+-catalyzed oxidative cyclization of 2-allylphenols
Substituted 2-methylbenzofurans were obtained from 2-allylphenols via Pd2+-catalyzed oxidative cyclization using Cu(OAc)2-LiCl as a reoxidant and wet DMF as a solvent.
Roshchin, Alexander I.,Kel'chevski, Sergey M.,Bumagin, Nikolai A.
p. 163 - 167
(2007/10/03)

Reactions of O,O-Diprotonated Nitro Olefins with Benzenes. Formations of Phenylacetones, 4H-1,2-Benzoxazines and Biarylacetone Oximes
O,O-Diprotonated nitro olefins undergo three alternative electrophilic reactions which yield α-phenylacetones, 4H-1,2-benzoxazines and biphenylacetone oximes depending on the reaction conditions (temperature and time) and aromatic substrates.Although these reactions are seemingly divergent, a common intermediate of a phenylated protonated aci-nitro species, derived from the dication, is postulated to be involved in the reactions.Furthermore, the formation of benzoxazines and biphenylacetone oximes can be interpreted in terms of participation of novel chemical species with phenylethylene dication character derived from the common intermediate.
Ohwada, Tomohiko,Okabe, Kazuaki,Ohta, Toshiharu,Shudo, Koichi
p. 7539 - 7555
(2007/10/02)

Novel Electrophilic Species Equivalent to α-Keto Cations. Reactions of O,O-Diprotonated Nitro Olefins with Benzenes Yield Arylmethyl Ketones
The N,N-dihydroxyiminium carbenium ions formed by O,O-diprotonation of nitro olefins in a strong acid, trifluoromethanesulfonic acid (TFSA), are discrete and novel dipositively charged species.The dications formed from α-substitited nitroethylenes are reactive electrophiles to give α-arylated ketones in high yields.This constitutes a versatile synthetic method for the preparation of α-arylated ketones, which are difficult to synthesize by the conventional Friedel-Crafts reactions.
Okabe, Kazuaki,Ohwada, Tomohiko,Ohta, Toshiharu,Shudo, Koichi
p. 733 - 734
(2007/10/02)

Process for producing phenylacetones
A phenylacetone or its derivative having the general formula (I): STR1 wherein X, Y, and Z are independently a hydrogen atom, a hydroxyl group, a halogen atom, a nitro group, an amino group, a lower alkyl group having 1 to 6 carbon atoms, a lower alkoxy group having 1 to 6 carbon atoms, or a benzyloxy group and any two substituents of X, Y, and Z may form, together with the benzene ring, a heterocycling ring having 5 to 7 members including 1 or 2 oxygen atoms is produced at a high yield and a high selectivity by reacting a 3-phenylpropylene or its derivative having the general formula (II): STR2 wherein X, Y, and Z are as defined above, with an alkyl nitrite having the general formula (III): wherein R is an aliphatic, aromatic, or alicyclic saturated or unsaturated hydrocarbon group in the presence of (a) water, (b) an alcohol, (c) a palladium catalyst, and (d) an optional amine or copper compound, or by reacting the above-mentioned 3-phenylpropylene or its derivative with the above-mentioned alkyl nitrite in the presence of (a) an alcohol, (b) a palladium catalyst and (c) an optional amine or copper compound to form 1-phenyl-2,2-dialkoxypropane or it derivative having the general formula (IV): STR3 wherein X, Y, Z and R are as defined above, followed by hydrolyzing the reaction product.
-
(2008/06/13)

Arylation and 1-Alkenylation on α-Position of Ketones via Tributyltin Enolates Catalyzed by Palladium Complex
The reaction of tributyltin enolates, prepared from tributyltin methoxide and enol acetates in situ, with aryl and 1-alkenyl bromides in the presence of dichlorobis(tri-o-tolylphosphine)palladium was found to give α-aryl and α-(1-alkenyl) ketones, respectively, in good yields with essentially complete retention of the enol acetate regiochemistry.
Kosugi, Masanori,Hagiwara, Isao,Sumiya, Takao,Migita, Toshihiko
p. 241 - 246
(2007/10/02)

ACETONYLATION AROMATIQUE HOMOLYTIQUE
Treatment of monosubstituted benzene derivatives with acetone and manganese(III) acetate in acetic acid gave rise to products of homolytic aromatic substitution in fairly good yields and high purity except for toluene.Isomer distribution, relative rates and partial rate factors were determeined for toluene, anisole, chlorobenzene, bromobenzene and benzonitrile.A Hammet plot of the logarithm of the partial rate factors for meta and para positions vs. ?-constants gave a slope ρ of -1.74 +/- 0.40 (confidence interval at the level 95percent).When using ?+-constants the slope becomes ρ+ = -1.25 +/- 0.36.The negative velues of ρ and ρ+ indicated that the acetonyl radical has an appreciable electrophilic character.
Gardrat, C.
p. 897 - 902
(2007/10/02)

Aromatic Acetonylation Promoted by Manganese(III) and Cerium(IV) Salts
Treatment of aromatic hydrocarbons with acetone and manganese(III) acetate gave rise to arylacetones in yields ranging from 25 percent with chlorobenzene to 74 percent with anisole.Cerium(IV) salts were also successfully used as promoters but gave lower yields.The reactions were relatively free of side products except with toluene.Isomer distributions, relative rates, and partial rate factors were determined for acetonylation of anisole, toluene, chlorobenzene, and fluorobenzene.A Hammett plot of the log of the partial rate factors for the manganese(III) system vs. ?-constants gave a slope, ρ, of -2.4 +/- 0.3.An isotope effect kH/kD = 3.8 was observed for the manganese(III)-promoted reaction with acetone-d6, indicating rate-determining proton loss from acetone.The overall mechanism involves formation and attack of acetonyl radicals onto the aromatic hydrocarbon followed by subsequent oxidative deprotonation of the resulting ?-radical complex.The acetonyl radical exhibits appreciable electron-deficient character in its substitution behavior with aromatic hydrocarbons.
Kurz, Michael E.,Baru, Vijayalakshmi,Nguyen, P-Nhi
p. 1603 - 1607
(2007/10/02)

New Synthesis of Benzofurans by SRN1 Reaction of ortho-Iodoanisole
Starting from ortho-iodoanisole, 2-substituted benzofurans are obtained in high yield via aromatic nucleophilic radical substitution (SRN1).
Beugelmans, Rene,Ginsburg, Helene
p. 508 - 509
(2007/10/02)