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Arylation of simple arenes

Recent progress in the palladium-catalysed direct arylation of simple arenes involving both intra- and inter-molecular reactions has been reviewed.55 The review includes a mention of mechanistic aspects. A new Pd11-catalysed method for the direct 2-arylation of indoles and pyrrole has been reported.56 This IMesPd(OAc)2-catalysed... [Pg.196]

Campeau L-C, Fagnou K (2006) Palladium-catalyzed direct arylation of simple arenes in synthesis of biaryl molecules. Chem Commun 1253-1264... [Pg.273]

Palladium-catalysed direct arylation of simple arenes in the synthesis of biaryl molecules , Campeau, L.-C. and Fagnou, K., Chem. Commtm., 2006, 1253. [Pg.95]

Among the few known methods for catalytic direct arylations of simple arenes with aryl halides, early examples are represented by direct arylations of azulene (Scheme 9.29) [67] and of benzene [68]. [Pg.275]

Following Fagnou s reports, various catalysts and conditions for the C-H arylation of simple arenes with aryl halides were developed, as shown in Scheme 17.9. [Pg.1325]

In 2007, Kempe [33] also reported a rhodium-catalyzed C-H arylation of simple arenes. They developed a bimetallic rhodium catalyst 38 that can arylate benzene with bromo- and chloroarenes. [Pg.1327]

During the past few decades, intramolecular C-H arylation of simple arenes with aryl halides has been applied to the synthesis of biological compounds such as natural products, pharmaceuticals as well as organic materials. Herein, some recent applications of intra- and intermolecular C-H arylation of simple arenes with aryl halides are described (Scheme 17.10). [Pg.1327]

Since 2008, C-H/C-M coupHng reactions without directing groups were reported using various organometaUic reagents and transition metal catalysts (Scheme 17.38). In 2008, Shi [178a] reported a C-H arylation of simple arenes... [Pg.1359]

Rhodium-catalyzed direct arylations of simple arenes has undergone a drastic change in the last few years with the development of protocols employing phosphinites as co-catalysts. The important feature of this... [Pg.72]

Fagnou and co-workers disclosed an effective palladium-catalyzed protocol for direct arylations of unactivated arenes using aryl bromides.A catalytic system comprising of [Pd(OAc)2] and DavePhos as ligand, along with substoichiometric amounts of pivalic acid 78, generated a highly active catalyst for the arylation of simple arenes like benzene 6 (Scheme 20). [Pg.79]

Shi has reported a method for /V-alkylanilidc arylation by simple arenes [53], The reaction conditions include heating the anilide with excess arene in propionic acid in the presence of catalytic palladium acetate and copper triflate under oxygen atmosphere. Use of monosubstituted arenes leads to the formation of isomer mixtures however, from the point of atom economy C-H/C-H couplings are the most efficient way for formation of C-C bonds if oxygen is used as the terminal oxidant. Shi has also reported that anilides can be coupled with arylboronic acids and trialkoxyaryl-silanes [54, 55], Silver and copper salts are used as terminal oxidants. [Pg.66]

The remarkable stability of ruthenium complexes could, further, be exploited for direct arylations between simple arenes as pronucleophiles and inexpensive, broadly available phenols as proelectrophiles. Notably, this operationally simple dehydrative direct arylation was achieved with a highly chemo- and regioselective ruthenium catalyst, along with a sulfonyl chloride, and proceeded overall through the functionalizations of both C-H as well as C-OH bonds (Scheme 29) [85],... [Pg.224]

The last decade has seen an explosive growth in the development of palladium catalyzed C—H bond activation reactions [81]. These have provided intriguing methods to couple the C—H bond of simple arenes with activated aryl halides, and... [Pg.185]

Scheme 17.8 C-H/C-X coupling of simple arenes and aryl halides. Scheme 17.8 C-H/C-X coupling of simple arenes and aryl halides.
In 2006, Itami [32] reported a rhodium-catalyzed C-H arylation. The newly developed catalyst, RhCl(CO) P[OCH(CF3)2]3 2, is readily prepared, air stable, and able to promote the C-H coupling of heteroarenes and iodoarenes. The C-H/C-X coupHng of simple arenes can also be accompHshed. For example, the coupling of 1,3-dimethoxybenzene and iodobenzene proceeded in the presence of the aforementioned rhodium catalyst, Ag2COj, and 1,2-dimethoxyethane in m-xylene at 200 °C (microwave) to afford the corresponding couphng product in 76% yield. [Pg.1327]

Recently, Luo and coworkers reported the arylation reaction of simple arenes with perfluoroben-zoic acids by use of a Pd/Ag bimetalhc catalyst system to give perfluorobiaryls, in which aryl halides and triflates were directly replaced by simple arenes (Scheme 22.42b) [61b]. [Pg.633]

Aryl sulfide scaffolds find important applications in the synthesis of bioactive molecules and organic semiconductors. Anbarasan and coworkers recently reported the first example of Pd-catalyzed direct phenylthiolation of simple arenes (Scheme 24.52) [46]. Pd(OAc)j serves as an efficient catalyst for the thiolation of various arenes using the succinimide reagent 56 as the source of the phenyl thiol moiety. Mono-, di-, and trisubstituted arenes participate in these reactions to afford the products in good to... [Pg.704]

Simultaneously, Chang s [101] and DeBoefs group [102] independently reported an intermolecular oxidative amination of simple arenes using PIDA as a stoichiometric oxidant (Scheme 37). The authors were able to arylate several... [Pg.98]

Silver salts have been used extensively as oxidants in many different types of biaryl CDC reactions, such as the arylation of indoles, " " azoles, thiophenes," " chromones, xanthines," uracils," and pyridine-iV-oxides." " " They are also used in the inter- and intramolecular coupling of simple arenes. ° Recently, Zhang and co-workers oxidatively coupled thiophene derivatives and fluorinated arenes, using only 2.5 mol% of Pd(OAc)2 as a catalyst and AgCOs as an oxidant (Scheme 6.8)." " ... [Pg.121]

The use of reactive metal electrodes are also effective for the silylation of various organic halides and simple arenes [75]. For instance, Dunogues et al. reported that electrolysis of aryl chlorides in the presence of excess Me3SiCl in a one-compartment cell equipped with a sacrificial aluminum anode in 80 20 THF/HMPA gave the corresponding aryltrimethylsilanes (Scheme 36). When... [Pg.82]

Yields of the arenes from the hydrazines are variable and generally low (<40%) for simple aryl compounds, although acceptable yields (50-90%) are obtained for the 7t-electron-deficient heteroaryl derivatives. In this respect, the procedure has some utility, as the more usual reductive conversion of haloheteroarenes into the parent... [Pg.217]

The catalytic activation of aromatic C-H bonds leading to useful addition with new C-C bond formation is of considerable interest in organic synthesis and industrial processes, because it would provide simple and economical methods for producing aryl-substituted compounds directly from simple arenes, as shown in Scheme 1. [Pg.194]

Whilst direct electrophilic hydroxylation of the arylthallium species can be effected using peroxytriflu-oroacetic acid, further oxidation of the phenol to a quinone accompanies this process. This over-oxidation can be avoided by initial transmetallation to a lead species with concomitant reduction of the thallium trifluoroacetate (TTFA) by triphenylphosphine, followed by displacement of the lead by trifluo-roacetate to give the aryl trifluoroacetate. lliis hydroxylation method has yet to find use in the synthesis of molecules which are more complex than simple arenes. [Pg.335]

The primary method of direct palladation begins with Pd and proceeds by either electrophilic aromatic substitution or oxidative addition of an arene C-H bond (equation 2) In both cases, loss of H-X leads to an aryl-Pd-X derivative. Simple arenes can undergo palladation, but lead to isomers in the absence of a strongly directing substituent. The process is usually done in a stepwise manner, with isolation of the aryl-Pd-X intermediate. It is not easily made catalytic various reoxidation recipes are used for conversion of Pd° to Pd in other applications, but none has been found satisfactory here. [Pg.3285]


See other pages where Arylation of simple arenes is mentioned: [Pg.281]    [Pg.281]    [Pg.67]    [Pg.298]    [Pg.298]    [Pg.380]    [Pg.287]    [Pg.1325]    [Pg.611]    [Pg.682]    [Pg.710]    [Pg.93]    [Pg.94]    [Pg.95]    [Pg.378]    [Pg.316]    [Pg.224]    [Pg.232]    [Pg.176]    [Pg.197]    [Pg.68]    [Pg.17]    [Pg.212]    [Pg.82]    [Pg.277]    [Pg.3]   
See also in sourсe #XX -- [ Pg.196 ]




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