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Benzo thiophenes, aryl

At present the most robust photochromic molecules are diarylethenes with benzo-thiophene aryl groups [13]. They undergo more than 1.3 x 10" photochromic cycles in the presence of oxygen without destruction. Recently crystalline photochromic diarylethenes have been developed [57, 58] which could repeat the cycles more than 10 times. [Pg.3414]

Intramolecular palladium catalyzed thio-enolate S-arylation has been used in a route to a set of fused benzo[ ]thiophenes, as illustrated by the conversion of the substrate 10 into the product 11 <06T11513>. [Pg.114]

Ab initio MO calculations have been carried out on benzo[. ]thiophene (BT), 2-methylbenzo[/ ]thiophene (2-MeBT), 3-methylbenzo[ ]thiophene (3-MeBT), and a number of organometallic complexes containing these thiophenic moieties in an attempt to understand the usual preference for insertion of metal fragments into the sulfur-carbon(vinyl) bond of BT and the recent observations of insertion into the sulfur-carbon(aryl) bond <19980M3798>. [Pg.633]

Examples of the former two reaction types are illustrated. An early Heck cyclization of 2-carboxy-2 -iododiphenylamine to 1-carbazolecarboxylic acid (73% yield) [346] has been generally overlooked by subsequent investigators. A microwave method is useful for the synthesis of azaindoles from aminopyridines and ketones [347], and a variety of cyclopent[/ ]indolones and carbazolones are available using this Heck chemistry [348, 349]. The requisite enamines can also be generated in situ by the addition of 2-haloani-lines to alkynes with TiC [350]. The aryl Heck variation affords carbazoles [351-353] including novel indolo[3,2-/ ]benzo[/ ]thiophenes [353]. [Pg.146]

Pharmacologically Active Compounds. - 2-Aryl-3-alkoxybenzo[Z)]thiophens have been shown to possess hypolipidemic activity. Alkyl and poly-halophenyl esters of benzo[ ] thiophen-3-carbamic acid show antibacterial and antifungal activities. Benzo[Z ]thiophen-3-sulphonamides show herbicidal activity. Derivatives of 2-cyano-3-hydroxybenzo[Z>] thiophen show sympatholytic activity. ... [Pg.124]

Ohta and co-workers carried out extensive studies on intermolecular arylation of various heterocycles (furan, thiophene, pyrrole, oxazole, thiazole, A-methylimi-dazole, benz[fe]oxazole, benzo[i>]furan, and benzo[ ]thiophene) with mainly chlo-ropyrazines as heteroaryl halides using Pd(PPh3)4 and AcOK [3]. [Pg.177]

Benzo[ ] thiophene (18) is arylated with the aryl bromide 17 as expected at C-2 to afford 19 [3b], Intramolecular 3-arylation of the thiophene in 20 gave the tetracyclic /S-lactam 21 containing thiophene in the presence of TI2CO3 as a base [6],... [Pg.180]

Reaction at Sulphur.—The oxidation of benzo[6]thiophens to sulphoxides by t-butyl hypochlorite has been studied. In the presence of a ruthenium catalyst, dibenzothiophen was oxidized by oxygen to the sulphone. The reactions of benzo[ >]thiophen 1,1-dioxides with various reagents such as amines, amino-alcohols,3-aminopropylsilanes, and aromatic sulphonyl chlorides have been studied. Four detailed papers on the reaction of dibenzophenonium salts with aryl-lithiums have appeared in which the mechanism of ligand exchange was elucidated. " ... [Pg.287]

There are reports of an increasing number of palladium-assisted reactions, in some of which the palladium has a catalytic function. Thus furan and thiophene undergo facile palladium-assisted alkenylation giving 2-substituted products. Benzo[6 Jfuran and TV- acetyl-indole yield cyclization products, dibenzofurans and carbazoles respectively, in addition to alkenylated products (8UOC851). The arylation of pyrroles can be effected by treatment with palladium acetate and an arene (Scheme 86) (81CC254). [Pg.83]

Benzo[6]thiophene, 2-acetyl-3-hydroxy-synthesis, 4, 892 Benzo[6]thiophene, 2-acyl-synthesis, 4, 918 Benzo[6]thiophene, 3-acyl-synthesis, 4, 918- 19 Benzo[6]thiophene, acylamino-synthesis, 4, 815 Benzo[6]thiophene, alkenyl-synthesis, 4, 917 Benzo[6]thiophene, 2-alkoxy-synthesis, 4, 929 Benzo[6]thiophene, 3-alkoxy-synthesis, 4, 929 Benzo[6]thiophene, 4-alkoxy-synthesis, 4, 930 Benzo[6]thiophene, 2-alkyl-synthesis, 4, 877-878 Benzo[6]thiophene, 2-alkylthio-synthesis, 4, 931 Benzo[6]thiophene, 2-amino-diazotization, 4, 810 reactivity, 4, 797 stability, 4, 810 synthesis, 4, 869, 924-925 tautomerism, 4, 38 Benzo[6]thiophene, 3-amino-cycloaddition reactions, 4, 68 synthesis, 4, 109, 881, 925 Benzo[6]thiophene, 4-amino-synthesis, 4, 925 Benzo[6]thiophene, 5-amino-synthesis, 4, 925 Benzo[6]thiophene, 7-amino-synthesis, 4, 925 Benzo[6]thiophene, 3-t-amyl-synthesis, 4, 915 Benzo[6]thiophene, 2-aryl-synthesis, 4, 881... [Pg.559]

Benzo[6]thiophene, 3-aryl-2-methyl-1,1-dioxide synthesis, 4, 930... [Pg.559]

Diacyl-3,4-dihydroxythiophenes have been formulated as dienol tautomers (77T191). The same holds for 2,5-diaryl- and 5-aryl-2-carboxy derivatives (91JHC1449). ESR investigations of 6-halogeno-benzo[h] thiophene-2,3-semidiones (Scheme 13) have been reported (81JOC751). [Pg.112]

The two principal categories of compounds studied have been diaryl or aryl alkyl sulphones (not dialkyl sulphones, which are polarographically not reducible) and S-dioxides of certain heterocyclic compounds, such as thiophene (also benzo- and dibenzothiophenes) and phenothiazines. The first named have half-wave potentials in the region of — 2.0 V, the thiophene dioxides near — 1.0 V. Some examples of each category may be given. [Pg.108]

The synthetic approach to the benzo[fo]furan is similar to that of the thiophenes described in Scheme 39. The synthetic approach was described by Flynn et al. [73], and an example synthesis is given in Scheme 40. The appropriate iodophenol 104 is coupled to the aryl alkyne 111. The intermediate 155 is subsequently cyclized in the presence of an appropriately substituted aryl iodide, e.g., 107 under an atmosphere of carbon monoxide gas, to give the benzo[fr]furan chalcone derivative 156. Deprotection of the hydroxyl produces the target compound 157. [Pg.53]

Cyclization of a thiocarbonyl ylide with the C=C-bond of an aromatic ring was observed in the reaction of aryl biphenyl-2-yl ketones with di(tosyl)diazomethane in the presence of Rh2(OAc)4 (189). In the case where the aryl ring contains a 4-methoxy group, benzo[c]thiophene (164) was the only product formed. In contrast, when the aryl ring consists of a 2,4,6-trimethylphenyl group, compounds 165 and 166 were produced. It would seem that after 1,5-dipolar electrocyclization of the intermediate thiocarbonyl ylide occurs, aromatization then takes place by elimination of toluenesulfinic acid or methyl toluenesulfinate. [Pg.350]

Methyl- and 2-aryl-substituted benzo[fc]thiophenes (26) can be synthesized starting from o-toluenethiol in three steps, which involves the intramolecular addition of thiols, produced by acid hydrolysis, to the carbonyl group followed by dehydration as the final step (Scheme 3) (91JHC173). [Pg.609]

A concerted elimination-cyclization mechansim, involving a sulfenyl halide in a 1,3-butadiene-1-thio system, is the most probable mechanism for the formation of benzo[6 Jthiophenes from cinnamic acids or 4-aryl-2-butanones by treatment with thionyl chloride. The reactions shown in Scheme 5 have been carefully worked out, and the intermediates isolated (75JOC3037). The unique aspect of this synthesis is the reduction of the sulfinyl chloride (a) by thionyl chloride to form the sulfenyl chloride (b). The intermediate (b) was isolated and converted in pyridine to the 3-chlorobenzo[6]thiophene-2-carbonyl chloride in 36% yield (73TL125). The reaction is probably initiated by a sulfenyl ion attack on the aromatic ring, since it is promoted by electron-releasing groups para to the site of ring closure. For example, when X in (36) was N02, a 23% yield of (37), a mixture of 5-and 7-nitro derivatives, was obtained, but when X in (36) was OMe, a 54% yield of (37) was obtained, contaminated with some 3,4-dichloro-5-methoxybenzo[6]thiophene-2-carboxylic acid. [Pg.870]

Thiobenzophenone can also serve as a C3S intermediate in the synthesis of some benzo[c]thiophenes. The carbon source in this case is carbon monoxide. Reaction of various thiobenzophenones with diiron enneacarbonyl in benzene at room temperature produced a complex, Ar2CSFe2(CO)6, which could be oxidized to form 2-hydroxy-5-aryl-benzo[c]thiophenes (226e) in 60-80% yield (73JA4905). [Pg.893]


See other pages where Benzo thiophenes, aryl is mentioned: [Pg.121]    [Pg.393]    [Pg.467]    [Pg.824]    [Pg.101]    [Pg.721]    [Pg.277]    [Pg.120]    [Pg.122]    [Pg.266]    [Pg.180]    [Pg.597]    [Pg.449]    [Pg.858]    [Pg.388]    [Pg.284]    [Pg.36]    [Pg.561]    [Pg.561]    [Pg.47]    [Pg.865]    [Pg.623]    [Pg.36]    [Pg.763]    [Pg.785]    [Pg.823]    [Pg.892]   
See also in sourсe #XX -- [ Pg.11 , Pg.14 , Pg.258 ]




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1-Benzo thiophen

2-Aryl-substituted benzo thiophenes

5- Arylation benzo thiophene

Benzo thiophenes, aryl preparations

Benzo thiophenes, aryl reactions

Benzo thiophens

Thiophenes arylation

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