Methanes, diaryl

An important side reaction is the formation of diaryl methane derivatives ArCHaAr. Moreover poly substituted products may be obtained as minor products. Aromatic compounds have been treated with formaldehyde and hydrogen bromide or hydrogen iodide instead of hydrogen chloride. The formaldehyde may be replaced by another aldehyde the term Blanc reaction however stands for the chloromethylation only. 

Lithiumalanat in siedendem Bis-[2-methoxy-athyl]-ather reduziert 1,1-Diaryl-athylene bei gleichzeitiger Me-thylierung durch das Losungsmittel5 (Diphenyl-methan-Derivate werden ebenfalls methyliert6). Natrium-bis-[2-methoxy-athoxy]-aluminiumhydrid reduziert und methyliert selbst 1,1-Diphenyl-athylen (in Kohlenwasser-stoff-Losung)7 und Arene8. 

Wahrend Dichlor-aryl-methane zu 1,2-Dichlor- 1,2-diaryl-athane dimerisiert werden (Bd. XIII/2a, S. 443) erhalt man aus Dialkyl- bzw. Diaryl-dichlor-methanen unter Dimerisierung die entsprechenden Olefine (s. Bd. V/lb, S. 424f.) ... 

Unlike triarylmethane dyes, comparatively little work has been done with diaryl heteryl-, and aryl diheteryl methane compounds. Analogous to triarylmethanes, triheterylmethane dyes are also prepared using POCl3 and a ketone. The intermediate leuco compounds (similar to 65, see Scheme 8) are not isolated40 in the case of triheterylmethane leuco dyes. 

Diazonium salts react with bis(methylsulfonyl) methane (107) (X = S02CH3) to yield a 1,3-diaryl tetrazolinone (111). The reaction proceeds through an azo (108) and a tetrazene (109) intermediate, followed by hydrolysis under the alkaline conditions of the reaction to the carbonyl compound (110). An unexplained oxidation leads to the 1,3-diaryl tetrazolinone (111) either directly or through the intermediate 110a (Scheme 15).18,35 A similar reaction occurs between a diazonium salt and the potassium salt of phenyl hydrazonomethane disulfonic acid (Scheme 15).175... 

Merriman and colleagues have reported the cydization of N-acyl-l,2-diaryl-l,2-ethanediamine derivatives, obtained by way of a solid-phase approach, to 4,5-diaryl-imidazolines by treatment with trimethylsilyl polyphosphate (TMS-PP) in dichloro-methane solution (Scheme 6.204) [367]. The best results were obtained by micro-... 

Diaryl and triaryl benzylic alcohols generally undergo smooth reduction to the corresponding hydrocarbons. Thus, both diphenyl- and triphenylcarbinol quickly give good to excellent yields of the corresponding substituted methanes when... 

Meyerson, S. Drews, H. Field, E.K. Mass Spectra of Ortho-Substituted Diaryl-methanes. J. Am. Chem. Soc. 1964, 86, 4964-4967. 

Diaryl- and triaryl-methane dyes also fall into this class [(124) is known as Michler s Hydrol Blue] and a number of the heterocyclic derivatives of these dyes are well known. Introduction of a sulfur bridge into Michler s Hydrol Blue (124) results in the dye Thiopyronine (125) which absorbs at 565 nm. The analogous dye with an oxygen bridge, Pyronine, absorbs at 545 nm and that with an —NH— bridge, Acridine Orange, absorbs at 490 nm (B-76MI11201). 

Direct irradiation of 2,5-dihydrofuran (175) results in the formation of furan, tetrahydrofuran, and the isomeric oxiran (176).146 Certain 2,5-dihydrothiophen derivatives are similarly converted to the corresponding vinylthiirans,147 whereas 5,5-diaryl-2,5-dihydrofurans are reported to undergo di-7i-methane rearrangement.148 An unexpected transannular phototransformation has been observed on irradiation of the l,3-dioxolen-2-one (177)... 

Arylmethyl(homobenzyl)ethylsulfonium salts are appropriate substrates for Suzuki-type coupling reactions. In this reaction, performed on a polymer-bound sulfonium tetrafluoroborate, the benzyl fragment on the sulfur atom was transferred to the boronic acid residue. The sulfonium salt was prepared from an al-kylthiol resin by alkylation with a substituted benzyl halide to give thioether 98 and subsequent alkylation with triethyloxonium tetrafluoroborate. Reaction with a boronic acid derivative yielded diaryl methanes 99 [94] (Scheme 6.1.22). 

Formaldehyde diaryl acetals are simply converted to the corresponding chloro- and dichlorobis(aryloxy)methanes by reaction with S02C12/AIBN or C12/AIBN851. 1,3-Dioxalane js converted to ClCH2CH2COOH by the former reagent at 55 °C852. 

Diaryl- -(tu-hydroxy-ethylester) E2, 210 1-Diazo-alkan- -ester E2, 398 (l-Diazo-ethan)-phenyl- -methylester E2, 399 (Diazo-phenvl-methan)-phenyl- -methylester E2,... 

Acetic, succinic and malonic acids (Table 1) are reported (4) to derive from Ar-CHa, Ar(CH2)2Ar (including hydroaromatic) and Ar-CH2 Ar (Ar - aromatic ring) units respectively. Examination of the concentrations of these major aliphatic products suggests that the medium lithotypes contain the highest concentrations of aryl methyl and Ar(CH2)2Ar structures. Diaryl methane units are proposed to be most significant in the pale lithotype possibly reflecting a resin input. 

Enantioface selection of prochiral diaryl ketones is generally difficult because electronically and sterically similar two aryl groups are attached to the carbonyl group. Overreduction of diaryl methanols to diaryl methanes is also another problem, but these problems are overcome by use of the Ru ternary catalyst system (Scheme 2.4b). Thus, by using (S,S)-20/KOC(CH3)3, 2-substituted benzophenones are quantitatively reduced to the diaryl methanols without any detectable diaryl methanes [102], With 3- or 4-substituted benzophenones, enantioselectivities are moderate. Benzoylferrocene is hydrogenated in the presence of trans-RuCl2 (S)-tol-binap (S)-daipen and a base to afford the S alcohol in 95% e.e. 

Diaryl ketones, such as o-bromobenzophenone and fluorenone carboxylic acids," are reduced by HI and red phosphorus in acetic acid or propionic acid under reflux, giving o-bromophenylphenyl-methane and fluorene carboxylic acid in high yields. 

The Te—Te bond in diorgano ditellurium compounds is rather weak with a tendency to homolytic cleavage. Species that act as diradicals may insert into the Te —Te bond. Dialkyl or diaryl ditellurium compounds and diazomethane in diethyl ether solution produce bis[organotelluro]methanes ... 

The anodic oxidation of 2,2-bis(ethylthio)propane producing acetone and an oxidation product of diethyl disulfide, claimed to be the corresponding disulfoxide, was reported many years ago [133]. A renewed interest in this reaction involving a C-S bond cleavage arose when bis(phenylthio)methane and some of its p-substituted ring derivatives were anodically oxidized in dry MeCN on Pt electrodes and afforded diaryl disulfides and formaldehyde, with the latter identified after aqueous workup [39, 134]. The same cleavage was observed when MeCN-H20 (9 1 v/v) was the solvent, but aryl benzenethiosulfonates were the main products [39] ... 

More recently, trifunctional and tetrafunctional resins (Tactix 742, namely the triglycidyl ether of tn 5(hydroxyphenyl) methane, and Shell 1153, namely a diaryl-methylene-bridged DGEBA) have been trialled, but the alternative approach of curing glycidyl amine resins with aromatic amines has proven to be more widely employed to achieve high Tg. These resins were shown earlier in Scheme 1.4. 

Diazo-3H-indazol reagiert mit Diaryl-diazo-methanen in einer [11+1 ]-Cycloreaktion zu kon-densierten 1,2,4-Triazolen. So erhalt man mit Diazo-diphenyl-methan 3,3-Di.phenyl-3H-(l,2,4-triazolo[4,3-b]indazoiy472 [87% Schmp. 204 205° (Ethanol/Benzol)] ... 

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