Diphenyl derivatives

Martin, Aromatic Hydroxyketones Preparation and Physical Properties, 

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An interesting reaetion, which is particularly valuable for the preparation of diphenyl derivatives, consists in heating copper powder or, better, copper bronze with an aryl halide (Ullmann reaction), for example ... 

Except in the case of the 4,5-diphenyl derivatives, these compounds are obtained as their hydrohalide salts tvith yields of 70 to 90% the free heterocyclic base is obtained by treatment with weak alkali. 

A Hammett relationship of the form ApK = 5.8am has been proposed for 4-substituted pyrazoles (74TL1609) in order to explain the effect of 4-nitro ApK = 4.5, am = 0.71) and 4-diazo groups (Apiifa = 10.0, am = 1.76). The acidity constants of a series of pyrazolidine-3,5-diones have been determined (75AJC1583) and the 4- -butyl-1,2-diphenyl derivative phenylbutazone has a pK of 4.33. 

Cis- and trans-3,5-diphenyl derivatives 1,3-Diradical mechanism 76T619... 

Figure 4.2. Rotational-energy barriers as a function of substitution. Tbe small barrier ( 2kcal) in ethane (a) is lowered even further ( O.Skcal) if three bonds are tied back by replacing three hydrogen atoms of a methyl group by a triple-bonded carbon, as in methylacetylene (b). The barrier is raised 4.2 kcal) when methyl groups replace the smaller hydrogen atoms, as in neopentane (c). Dipole forces raise the barrier further ( 15 kcal) in methylsuccinic acid (d) (cf. Figure 4.3). Steric hindrance is responsible for the high barrier (> 15 kcal) in the diphenyl derivative (e). (After...

Another structure with a 10-7r-electron conjugated system is bicyclo[6.2.0]deca-1,3,5,7,9-pentaene. The crystal structure of the 9,10-diphenyl derivative (Fig. 9.6) shows the conjugated system to be nearly planar. " ... 

The fluoride [NS(0)F]3 is more stable thermally and towards nucleophilic reagents than the corresponding chloride. For example, 8.15a is hydrolyzed by water to NH(S02NH2)2, whereas sulfanuric fluoride is unaffected by cold water. In warm water, however, hydrolysis occurs to give the [N3S304F2] anion. All three fluorine atoms in [NS(0)F]3 can be replaced by primary or secondary amines at 80-90°C in the absence of a solvent. Mono- or diphenyl derivatives can be prepared by treatment of [NS(0)F]3 with PhLi in diethyl ether at -70°C, while the Friedel-Crafts reaction with benzene at reflux in the presence of AICI3 gives two isomers of [NS(0)Ph]3. ... 

The bicyclic oxepin 8//-3-oxacyclohept[d]oxepin-8-one dissolved in trifluoroacetic acid undergoes a rearrangement to the expected phenol derivative 1. Substituents in the 2- and/or 7-position of the oxepin part, however, give rise to the formation of l-acylazulen-6-ols 2 by ring contraction.148 The 2,7-diphenyl derivative affords a mixture of l-benzoyl-2-phenylazulen-6-ol (37%), l-benzoyl-2-phenylazulen-6(l//)-one (35%), and 2-phenylazulen-6-ol (23%), which was presumably formed via the azulenone and a shift of the benzoyl substituent to the oxygen. 

Dibenz[c 1c ]azepine (32 a) is obtained by acid-mediated cyclization of 2 -(aminomethyl)bi-phenyl-2-carbaldehyde (31 a), which is generated in situ by reduction of the oxime acetal 30a.85 The acetyl 30 a and benzoyl 30c oximes behave similarly and give the dimethyl and diphenyl derivative 32 b and 32 c, respectively. 

In contrast, the diphenyl derivative 44 (R1 = R2 = Ph) fails to ring expand, whereas the methyl derivative 44 (R1 = Me R2 = H) yields the a.xo-methylene compound 45 (63 %), which undergoes quantitative acid-catalyzed isomerization to 10-methyl-5/7-dibenz[6,/]azepine (46) in refluxing toluene. The mechanistic implications of these reactions have been discussed. 

From the thermal rearrangement of the diphenyl derivative 5 (R1 = R2 = Ph) a product, isomeric with the triphenyl-5/A-2-bcnzazepine 7 (R1 = R2 — Ph), is produced in 28% yield which, oil the basis of its H NMR spectrum, has been identified tentatively as 1,3,4-triphenyl-3//-2-bcnzazepine. 

Of the 4-methylene-1,3-dioxolanes reported thus far (Table 4.6), only the 2,2-diphenyl derivative (50) is reported to give the polyketone quantitatively (Scheme 4.32). This requires temperatures in excess of 120 °C in bulk polymerization."... 

Several dihydrotetrazine materials have been promoted as oxygen scavengers, including 3,6-dimethyl,1-2-dihydro,1,2,4,5-tetrazine, and the diethyl- and diphenyl-derivatives. 3,6-Dimethyl,1-2-dihydro,1,2,4,5-tetrazine is a six-sided ring with a formula H3C-CN2C-CH3NHNH its MW equals 102. Its basic reaction with oxygen is shown here ... 

The C—S bond lengths vary upon changing carbon valence states. However, the sulfones and sulfoxides show less sensitivity to these changes than the analogous sulfides . These effects can be illustrated by considering the C—S bond lengths (A) in analogous dimethyl and diphenyl derivatives ... 

The diphenyl derivative 22—due to its peculiar property to form equally stable zwitterion and o-QM species—was a nice probe to search for conditions stabilizing the... 

FIGURE 6.20 Octyl derivative 21, diphenyl derivative 22 and its oxidation to zwitterion 23a, and sterically hindered o-QM 23. 

For the parent 2,3-dioxabicyclo[2.2.1]heptane 9 and its 1,4-diphenyl derivative 9 a, the multiplets for the remaining protons do not overlap and have been assigned on the basis of coupling patterns and comparison with the corresponding cw,exo-5,6-dideuterio derivatives 28),... 

See papers by Roger Adams and associates on diphenyl derivatives in J. Am. Chem. Soc. 

Related results in this area have been reported studying the synthesis and the reactivity of zirconium-butadiene functionality bonded to the j9-Bu -calix[4]-(0)2 (OMe)2 dianion.30 The synthesis of the parent compound used in this study, 43, is displayed, along with the analogous diphenyl derivative, in Scheme 7, and its structure in Fig. 5. 

With l,3>5-cycloheptatriene 2 can be trapped to yield four isomeric [2+2] adducts and the exo/endo isomeric [6+2] compound 16. Heating this mixture to 110°C leads to the complete transformation of the silacyclobutanes into 16 via a dipolar intermediate. The attempted synthesis of the diphenyl derivative of the [2+2] products leads to the stereospecific formation of endo-Yl which could be characterized by X-ray diffraction analysis [4]. 

A similar synthesis of chiral (o-hydroxyaryl)oxazaphospholidine oxides 166a-b, 167a-b, and 169a-d derived from (5)-prolinol 127 and its diphenyl derivative 163 was achieved from precursors 164a-b, 165a-b, and 168 which were easily available from two different procedures as outlined in Scheme 46 [77], The first pathway gave the two expected diastereomers of 164 and 165 in a ratio... 

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