Biphenyl 3,3 -dimethoxy

Irradiation of dianisyl alkyl phosphates gives alkyl phosphates and 4,4 -dimethoxy-biphenyl in yields exceeding 90%.6 As stated by the authors, this type of reaction appears to have promise for the synthesis of nucleotides. 

The least sol fraction was easily proved to be l,3,6,8-(or symmetrical) TeNCbz, because it was identical with the sample prepd by heating 3,3 5,5 -tetranitro-2,2 -dimethoxy-biphenyl in a sealed tube. The structure of the middle portion was not so easy to determine. It was at first believed to be 2,3,6,8-isomer but investigation by the method of infrared absorption spectra showed it to be 1,2,6,8 -TeNCbz. No other isomers were obtained by Murphy et al... 

Polyethylene is recognized as a semicrystalline polymer, where the prefix semi indicates that the material is not perfectly crystaUine (such as low molar mass compounds, e.g. dimethoxy biphenyl, which forms amazing crystals from supersaturated solutions) but rather is a nanophase-separated material that consists... 

A mixture of diisopropylethylamine (Hiinig s base, 1.74 ml, 10 mmol), palladium acetate (112 mg, 0.5 mmol, 5 mol%), tetra- -butylammonium bromide (1.61 g, 5 mmol) and 4-bromoanisole (110, 1.87 g, 10 mmol) in DMF (1.25 ml) was stirred under nitrogen at 115 "C for 96 h. After cooling to room temperature, water (50 ml) and diethyl ether (50 ml) were added. The organic phase was separated, washed with water and dried (MgS04). The solvent was evaporated in vacuo. Pure 4,4 -dimethoxy biphenyl (77, 514 mg, 48%) was obtained after purification with preperative chromatography, m.p. 172-173 "C. 

The triarylbismuth(III) reagents, ArjBi, smoothly undergo the homo-coupling reaction in the presence of a stoichiometric amount of palladium(II) acetate (1 eq. to Ar3Bi) and triethylamine (2 eq.), in tetrahydrofuran or far more efficiently in HMPA, to afford the symmetrical biaryls in almost quantitative yields [72], For exanple, tri(4-methoxy phenyl)bismuth (497) is converted to its homo-coupling product, 4,4 -dimethoxy biphenyl (77) in 98% yield [72], respectively. Scheme 38. 

Mortland, Pinnavaia and their co-workers have found that the adsorption of certain aromatic molecules on montmorillonites whose exchangeable cations are saturated with transition metal ions leads to the formation of colored complex(2-4). The IR spectrum of benzene complex formed under a dry atmosphere Indicates the chemical state of the adsorbed benzene is remarkably different from that of liquid benzene (2,3), while adsorbed anisole is reported to dimerize to 4,4 -dimethoxy-biphenyl(5). The essential step in the formation of these colored complexes has been shown to involve an electron transfer from the adsorbed organic molecules to the interlayer transition-metal ion, notably by ESR(4,6). However, the detailed spectroscopic information concerning the structure of adsorbed species have not been sufficient. 

Bis( 1 -hydroxy-4-methylphenyl-2-azo ) benzene, polymers with Cu(II), 202 4,4 -Bis (1 -hydroxy-4-methylphenyl-2-azo)-3,3 -dimethoxy biphenyl, polymers with Cu(II), 203 4,4 -Bis( l-hydroxy-4-methylphenyl-2-... 

Chlorazol Sky Blue FF 6,6 -[(3,3 -dimethoxy[l,l -biphenyl]-4,4 -diyl)bis(azo)bis(4-amino-5-hydroxy-l,3-naphthylenedisulfonic acid) tetra-Na salt [2610-05-1 ] M 996.9, m... 

BIARVLS FROM SIMPLE ARENES via ORGANOTELLURIUM INTERMEDIATES 4,4-DIMETHOXY-l.I -BIPHENYL... 

The present method of preparation of 4,4 -dimethyl-l,l -biphenyl is that described by McKillop, Elsom, and Taylor 15 It has the particular advantages of high yield and manipulative simplicity and is, moreover, applicable to the synthesis of a variety of symmetrically substituted biaryls 3,3 - and 4,4 -Disubstituted and 3,3, 4,4 -tetrasubstituted 1,1 -biphenyls are readily piepared, but the reaction fails when applied to the synthesis of 2,2 -disubstituted-l,T biphenyls The submitters have effected the following conversions by the above procedure (starting aromatic bromide, product biphenyl, % yield) bromobenzene, biphenyl, 85,1 -bromo-4-methoxybenzene, 4,4 -dimethoxy-l, 1 -biphenyl, 99, 1 bromo 3 methylbenzene, 3,3 dimethyl-1,l -biphenyl, 85 4-bromo-l,2-dimethylbenzene, 3,3, 4,4 -tetramethyl-l,l -biphenyl, 76, l-bromo-4-chlorobenzene, 4,4 -dichloro-l,l -biphenyl, 73, l-bromo-4-fluorobenzene, 4,4 -difluoro-l,l -biphenyl, 73... 

MeOBIPHEP is the atropisomeric diphosphine 2,2,-bis(diphenylphosphino)-6,6 -dimethoxy-l,-l -biphenyl (100), has been synthesized. In the presence of SnCl2, this species is an efficient catalyst for the asymmetric hydroformylation of styrene. Asymmetric inductions are higher than those attainable using the system [PtCl2 (i )-(+)-BINAP ]/SnCl2, where BINAP is 2,2 -bis(di-phenylphosphino)-l,l,-binaphthyl. The influence of CO and H2 partial pressures on the catalytic activity of the (99)/SnCl2 system has also been studied.328 Complexes [PtMeCl(P-P)][(101), P-P = (5)-6,6,-(dimethoxybiphenyl)-2,2,-diylbis(diphenylphosphine) ((5)-MOBIPH) (102),... 

Dimethoxybenzoyl chloride Benzoyl chloride, 2,3-dimethoxy- (9) (7169-06-4) 2-Amino-2-methyl-1-propanol 1-Propanol, 2-amino-2-methyl- (8,9) (124-68-5) 2,2 -Dimethoxy-6-(4 ,4 -dimethyloxazolinyl)biphenyl Oxazole, 2-(2 ,6-dimethoxy[1,1-biphenyl]-2-yl)-4,5-dihydro-4,4-dimethyl- (9) (57698-39-7)... 

Nitroblue tetrazolium (NBT, 3,3 -(3,3,-dimethoxy-l,l,-biphenyl-4,4 -diyl)bis-2-(4-nitrophe-nyl)-5-phenyl-2H-tetrazolium dichloride) is reduced by superoxide to formazan as a final product, which can be measured spectrophotometrically [73]. Although the rate constant for NBT reduction by superoxide is moderately high 5.88+0.12x 104 1 mol 1 s 1 [74], the formation of formazan is not a simple one-electron transfer process, and the final product is formed as a result of disproportionation of intermediate free radicals. Similar to cytochrome c, NBT is easily reduced by the other reductants that confines its application for superoxide detection. Moreover, similar to epinephrine, NBT free radical is apparently... 

A second example from the same group is the synthesis of an elaborate diethynyltriphenylene derivative (Scheme 7 Table 8,entries 12,13) [58].Zn/Pd-promoted homocoupling of a 4-iodo-l,2-dialkoxybenzene furnishes the desired tetraalkoxybiphenyl, an electron-rich aromatic system. Iron trichloride-catalyzed Friedel-Crafts arylation of the biphenyl derivative with dimethoxy-benzene furnishes an unsymmetrical triphenylene derivative. Deprotection, oxidation, and subsequent Diels-Alder reaction with cyclohexadiene is followed by catalytic hydrogenation and reoxidation. TMS-CC-Li attack on the quinone delivers the alkyne modules, treatment with SnCl2 aromatizes the six-mem-bered ring, while KOH in MeOH removes the TMS groups cleanly to give the elaborate monomer. 

The combination of rhodium dicarbonyl acetylacetonate complex (Rh(acac)(CO)2) and a diphosphite ligand, (2,2 -bis[(biphenyl-2,2 -dioxy)phosphinoxy]-3,3 -di-/i t/-butyl-5,5 -dimethoxy-l,T-biphenyl (BIPHEPHOS), is an excellent catalyst system for the linear-selective hydroformylation of a wide range of alkenes. This catalyst system has been successfully applied to the cyclohydrocarbonylation reactions of alkenamides and alkenylamines, which are employed as key steps for the syntheses of piperidine,indolizidine, and pyrrolizidine alkaloids. ... 

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