O phenylation

A con jugated sp - -sp --" single bond (for example, the bond joining the tw o phenyl rings of biphenyl, the central bond of butadiene, with delocali/ed aromatic bonds, or phenyl amine, where N-G bond is labeled aromatic and nitrogen is sp2 b h ybridi/ed) IS described by a two-fold barrier, V2=l() kcal/mol. 

This rapid formation of the crystalline quinoxaline derivative can therefore be used to identify 1,2-diketones conversely, a nuclear-substituted o-phenyl-enediamine can be identified by the quinoxaline derivative which it forms with a known 1,2-diketone such as benzil. 

The glycidic esters are of interest primarily because upon hydrolysis aud decarboxylation they aflFord aldehydes (if ClCHjCOOEt is used) or ketones (if substituted chloroacetic esters- ClCHRCOOEt are employed) having a higher carbon content than the original aldehyde or ketone. Thus (I) gives o-phenyl-propionaldehyde or hydratropaldehyde (II) ... 

The effect of an o>-phenyl group as a function of the alkyl chain length has been studied in 3-(through-space interaction has been evidenced on the reactivity of the thiocarbonyl group. 

This reaction is so facile that it is of value both for preparative and characterization purposes, Benzil and phenanthraquinone are convenient reagents for the characterization of o-diamines, and o-phenyl-enediamine is used commonly for the characterization of ff-dicarbonyl compounds. 

Chemical Name 4-(/3-methoxyphenethyl)-o -phenyl-1-piperazinepropanol Common Name -Structural Formula ... 

The 2-phenyl-2-ethyl-pentane-1,5-diacid-mononitrile-(1) of melting point 72° to 76°C, used as starting material in this process, can be produced for example from o-phenyl-butyric acid nitrile by condensation with acrylic acid methyl ester and subsequent hydrolysis of the thus-obtained 2-phenyl-2-ethyl-pentane-1,5-diacid-monomethyl ester-mononltrile-(l) of boiling point 176° to 185°C under 12 mm pressure. 

Chemical Name o -phenyl-2-piperidineacetic acid methyl ester... 

Aromatic compounds can also be arylated by aryllead tricarboxylates. Best yields ( 70-85%) are obtained when the substrate contains alkyl groups an electrophilic mechanism is likely. Phenols are phenylated ortho to the OH group (and enols are a phenylated) by triphenylbismuth dichloride or by certain other Bi(V) reagents. O-Phenylation is a possible side reaction. As with the aryllead tricarboxylate reactions, a free-radical mechanism is unlikely. ... 

The coordinatively unsaturated [Ni(PPh3)3] (1034) has trigonal planar Ni,2502 the structure showing some close approach of three o-phenyl H atoms to the central Ni (2.74-3.09 A) with implications for ortho-metallation. 

Butane, 1,4-diiodo-, 30, 33 2-Butanone, 3-acetamido-, 33,1 n-BuTYLACETYLENE, 30, IS tert-Butyl alcohol, 30, 19, 20 32, 20 ierl-Butylbenzene, 32, 91 n-Butyl bromide, 30, 16 tert-Butyl hypochlorite, 32, 20 n-Butyl iodide, 30, 34 Butylketene dimer, 31, 71 -ter -Butylphenyl salicylate, 32, 26 Butyrchloral, 33, IS Butyric acid, a, y-dicyano-o-phenyl-, ethyl ester, 30, 80... 

The Ru porphyrin complex (8) has also been used as a catalyst for the cyclization of allylic diazoacetates,258 albeit with limited success only the cyclization of F-cinnamyl diazoacetate shows high enantioselectivity (Scheme 81). It is noteworthy that a carbenoid species prepared from allyl o-phenyl-o-diazoacetate and complex (8) has been isolated and subjected to X-ray diffraction analysis, though it does not undergo the desired cyclization. In the structure, the carbene plane lies almost halfway between the two adjacent Ru—N bonds. 

DPA) in dimethylphthalate at about 70°, yields a relatively strong blue Umax =435 nm) chemiluminescence the quantum yield is about 7% that of luminol 64>. The emission spectrum matches that of DPA fluorescence so that the available excitation energy is more than 70 kcal/mole. Energy transfer was observed on other fluorescers, e.g. rubrene and fluorescein. The mechansim of the phthaloyl peroxide/fluorescer chemiluminescence reaction very probably involves radicals. Luminol also chemiluminesces when heated with phthaloyl peroxide but only in the presence of base, which suggests another mechanism. The products of phthaloyl peroxide thermolysis are carbon dioxide, benzoic acid, phthalic anhydride, o-phenyl benzoic acid and some other compounds 65>66>. It is not yet known which of them is the key intermediate which transfers its excitation energy to the fluorescer. 

Azacycloheptatrienylidene (4b), the aza analogue of cycloheptatrienylidene (4a), has on occasion been postulated to be the product of the ring expansion of lb.la In contrast to the case with 34a,lla 34b has never been directly detected. However, Iwamura and co-workers have reported chemical trapping of 4b and its o-phenyl derivative (4c) by tetracyanoethylene (TCNE), as shown in Scheme 15 49 While the product in Scheme 15 is formally the product of reaction of 4b with TCNE, the authors noted that it could also arise from reaction of TCNE with ketenimine 3b. 

I, 3,5-hexatriene and l-[4-(trimethylammom o)phenyl]-6-phenyI-l,3,5-hexatrieneanisotropy decay, Biochemistry 26, 5113-5120 (1987). 

Diethyl O-phenyl phosphate, see Parathion Diethyl phosphorothioate, see Phorate 0,0-Diethyl 5 4-nitrophenyl phosphorothioate, see Parathion... 

Fig. 5. Ei/a values for the reduction of Co + chelates in correlation with pKn values for the axial ligands. Equatorial chelating groups (1) bisdimethylglyoxi-mato (2) N,N -ethylenefeis(acetylacetoneiminato) (3) N,N -ethylene6is(methyl-salicylideneiminato) (4) N,N -ethylene6/s(salicylideneiminato) (5) N,N -o-phenyl-eneWs (salicylideneiminato)...

Observations on O-phenyl compounds have been mentioned previously (Section III.B.7(f)) in these compounds the phosphorus coupling to the para protons is as great as that to the ortho protons (1966> 75 i967,ii7) which leads to similar conclusions regarding the geometry of such derivatives and the coupling mechanism. 

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