Triaryl methyls

Triarylmethylazoles can also be synthesized by azole-transfer reactions of triaryl-methyl halides or acetates with azolides. In a similar manner 2,4,6-trinitro-phenylazoles are obtained from 2,4,6-trinitrophenyl chloride ... 

The thermal decomposition of triaryl methyl azides is first order, and the major products are mixtures of benzophenone anils . For the reaction... 

The cleavage is an reaction that occurs by protonation of the oxygen atom followed by loss of the stable triaryl methyl carbocation. 

The rate of acidic hydrolysis was found [37] to increase by approximately one order of magnitude for each /r-methoxy substituent introduced. Thus the times required for the complete hydrolysis, in 80% acetic acid at room temperature, of 5 -protected uridine derivatives were found [37] to be trityl, 48 hr. monomethoxytrityl, 2 hr dimethoxytrityl, 15 min trimethoxytrityl, 1 min. The introduction of /)-methoxy substituents also leads [37] to progressively more reactive triaryl-methyl chlorides. Khorana and his co-workers have used the mono- and di-methoxytrityl protecting groups widely in oligonucleotide synthesis [39]. 

The rhodium(III) triaryls have pseudo-octahedral structures therefore, in the air-stable trimesityl rhodium, the three mesityl groups are arranged in /ac-positions, with ort/io-methyls blocking the other coordination sites (Figure 2.107). 

Phosphine, methyl-n-propylphenyl-rhodium complexes asymmetric hydrogenation, 6,250 Phosphine, neomenthyldiphenyl-rhodium complexes asymmetric hydrogenation, 6,250 Phosphine, phenyl-, 2,992 Phosphine, o-phenylenebis(dimethyl-, 2,993 Phosphine, p-phenylenebis(diphenyl-, 2,993 Phosphine, seleno-metal complexes, 2,664 bidentatc, 2, 664 Phosphine, triaryl-photographic stabilizer, 6,103 Phosphine, tributyl-, 2, 992 oxide... 

Trialkyl (triaryl)stannyl methacrylates were copolymerized with ethylene and methyl methacrylate and it was shown that the resulting copolymer offers improved mechanical properties as compared to ethylene, and high fungicidal activity. It was suggested that homopolymers and copolymers of triethylstannyl methacrylate contain a covalent and an ionic bond between the carboxy group and the tin atom 63). 

Cyclocondensation of the l,4-diaryl-2-methylmercaptopyrimidinium methyl sulfate 50 with aroylhydrazines in the presence of perchloric acid gave the 3,5,8-triaryl-l,2,4-triazolo[4,3-a]pyrimidinium perchlorates 52 [81GEP(D)147944] (Scheme 22). 

Low-temperature NMR spectrum of triaryl-A3-iodane 73, prepared from iodo-A3-iodane by the ligand exchange with aryllithium, shows two methyl singlets at 6 2.24 and 2.41 [112]. Simultaneous broadening of the methyl and biphenyl aromatic resonances at higher temperatures demonstrates that the temperature dependence is caused by the degenerate isomerization of p-tri-fluoromethylphenyl substituent between two equivalent sites (73 73 ). The... 

The solubility of rare earth hydrides in organic solvents is increased by appropriate additives, too. For this purpose the hydrides are reacted with electron-donor ligands such as alkyl benzoates, alkyl propionates, alkyl tolu-ates, dialkylethers, cyclic ethers, alkylated amines, N,N -dimclhylacelamide, AT-methyl-2-pyrrolidone, trialkyl and triaryl phosphines, trialkyl phosphates and triaryl phosphates, trialkyl phosphates, hexamethylphosphoric triamide, dimethyl sulfoxide, etc. Prior to use as a polymerization catalyst the prereacted mixture of the rare earth hydride plus the additive is prereacted with Al-alkyl-based Lewis acids in the temperature range of 60-100 °C for 10 min to 24 h [351,352]. 

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