Triphenyl compounds

Chloro-5,6-diphenyl-as-triazine readily undergoes methoxy-de-chlorination at 25° (< 12 hr) with methanolic methoxide and at 65° (4.5 hr) in non-basified methanol. The chloro group is also displaced by hydrazine (80°, 1 hr), ammonia (140°, 6 hr), and phenyl-magnesium bromide (70°, 12 hr), the latter forming the triphenyl compound 315.3-Chloro-6-phenyl-as-triazine is unstable to cold water or alkali and to hot alcohol or aqueous potassium carbonate. ... 

Triphenyl Compound of Group 15 Elements, the Case of AsPhs. 191... 

In triphenyl compounds, quite symmetric structures result with larger donors. In the DMF adduct of triphenyltinsaccharin165, the three phenyls lie almost symmetrically in the equatorial plane (CSnC from 116°-124° Sn-C 212.5 pm) and the axial O from the formamide and N from the benzisothiazolone are near-linear axial (NSnO = 176° Sn-N = 224.2 pm, Sn-O = 240.2 pm). 

The first derivative of 1,2,3-triazine to be prepared, the triphenyl compound (2, R = Ph), was obtained in 1960 by thermolysis of 1,2,3-triphenylcyclopropenyl azide (1, R = Ph)." The physical and spectral (IR and UV) properties of 2 were consistent with the assigned structure, and the presence of three contiguous carbon atoms was demonstrated by hydrolysis experiments, which resulted in formation of 1,2,3-triphenyI-butane-l,3-dione. Photolysis of 2 gave a mixture of nitrogen, benzo-nitriie, and diphenylacetylene. 

The nucleophilic reactivities of silyl enol ethers (58, R1 = alkyl) and silyl ketene acetals (58, R1 = 0-alkyl) have been measured for the triphenylsilyl (R2 = H5) substrate, and its perfluoro analogue (R2 = F5), using benzhydrylium cations as reference electrophiles.224 The triphenyl compound is 10 times less reactive than its trimethyl equivalent, but the perfluorination causes the C=C nucleophilicity to drop by 3-4 orders of magnitude. The new compounds have been placed on scales of nucleophilicity taken from the literature. 

Gilman s significant observation that triphenylchlorosilane is a catalyst in Wurtz-like reactions forming cyclic silanes appears to be due to intermediate formation of triphenylsilyl lithium (see Chapter 9 Cyclic Silanes). The triphenyl compounds are particularly good catalysts because the corresponding alkali-triphenylsilyl compounds are the most stable among the alkali-organo-silicon compounds. 

The triphenyl compound (150 X=S, R = Ph) has been prepared in high yield by phosphorus pentasulfide-pyridine treatment of the dibenzoyl isothiazole (149 X = S, R = Ph) (77HC(30)317, 79CB260). The isothiazole precursor has been obtained from the mesoionic l,3,2-oxathiazol-5-olate (148 X = S, R = Ph) by treatment with either dibenzoylacetylene (79CB260) or dibenzoylethylene (77HC(30)317). 

The pyrylium-3-olates (65) form salts under acidic conditions. The triphenyl compound (65 R = R = R" = Ph, R = H) is oxidized by air to the butenolide 73, which is also formed when a solution of the same precursor is photolyzed (A = 3660 A) in the presence of a benzophenone sensitizer. This oxidative rearrangement (65 R = R = R" = Ph, R = H - 73) has been rationalized in terms of the triketone intermediate 71 cyclizing to the zwitterion 72 followed by rearrangement. ... 

The so-derived enthalpy of formation of gaseous triphenylarsine oxide, 261 18 kcalmol , just overlaps the value obtained from rotating bomb calorimetry, 227.6 +15.6 kJ mol . While related success arises in the comparison of the values for triphenylphosphine oxide we admit our discomfort with the large error bars accompanying all of these values. As such, while we derive an enthalpy of formation of triphenylstibine oxide using the static bomb results for stibine—and thus enter this value into Table 1—we regrettably consider it pointless even to compare the E—O bond enthalpies for the three triphenyl compounds. 

As Sb Environmental samples (water/solid samples) Triphenyl compounds MED 50-125/ 30-75 ppb 102)... 

In a similar study for acrylonitrile and various di and triphenyl compounds of N,P,As,Sb and Bi the order of initiation activity decreased PhgP > PhgS >PhgN > Ph20 >... 

Crossland and Avellen110 observed that addition of trifluoroacetic acid to a chloroform solution of 28a and 28b shifts the equilibrium entirely toward the 4,5-dihydro tautomer (28a). Neutralizing the solution, however, restores the original equilibrium. Equilibrium positions were also determined for two other 3,6-diaryl compounds, and in both cases the equilibrium favored the 1,4-dihydro tautomer. The ratio of 4,4-dimethyl-3,6-diphenyl-1,4-dihydropyri-dazine (81) to the 4,5-dihydro tautomer is 3.4 1, the 3,5,6-triphenyl compound 35 is found solely in the 1,4-dihydro form, probably because of conjugation stabilization. 

After the first synthesis of a P-phosphinin derivative, the 2,4,6-triphenyl compound (1) <66AG(E)846>, and the isolation of the unsubstituted phosphinin (2) <7UA3293>, a dramatic development and an avalanche of publications followed. 

The triphenyl compound 64, m.p. 217°, is the only reported member of this ring system. Referred to as a derivative of 2,1,3,4,7-benzpentazole, it was prepared by the reaction of benzil with the appropriate diamino-triazole. 

As electro positivity increases, the azides of the heavier IV A elements shift toward a more hydrophile behavior. This pattern is qualitatively noticeable in the triorganyl element azides (see Table XFV for trimethyl compounds). The triphenyl compounds display a similar behavior [9,261,272]. Basically, all R3E1(N3) compounds are accessible from the respective chloro compounds and sodium azide in ether/water media [273]. 

We synthesized a ferroelectric liquid crystalline PMP by incorporating a fluorine-containing chiral LC group into the side chain [14]. Figure 11.17 shows the structure of the FLC-PMP, Poly-8, M = 4,200) bearing a chiral FLC side chain and the FLC molecule a fluorine-containing triphenyl compound, FTP. 

In the trialkyl and triphenyl compounds described cd>ove, the sucrose group is joined to tin via an... 

Triphenyl-6a-thiathiophthen (2) has been compared structurally with 3,4-diphenyl- and 2,4-diphenyl-6a-thiathiophthen (3). The difference between the S—S distances in the triphenyl compound is less than in the two disubstituted derivatives. 

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