19920-02-6

Basic information

• Product Name: Ethanone, tetrakis(4-methylphenyl)-
• CAS NO: 19920-02-6
• Molecular Formula: C30H28O
• Molecular Weight: 404.552
• Mol File: 19920-02-6.mol

Chemical Properties

• CAS DataBase Reference: Ethanone, tetrakis(4-methylphenyl)-(CAS DataBase Reference)
• NIST Chemistry Reference: Ethanone, tetrakis(4-methylphenyl)-(19920-02-6)
• EPA Substance Registry System: Ethanone, tetrakis(4-methylphenyl)-(19920-02-6)

Safety Data

• Hazardous Substances Data: 19920-02-6(Hazardous Substances Data)

Upstream product

• 56-23-5 tetrachloromethane 
• 611-97-2 bis(p-methylphenyl)-methanone 
• 5831-43-6 1,1,2,2-tetrakis(4-methylphenyl)ethylene 
• 913-86-0 tetra(4-methylphenyl)-1,2-ethanediol 

Downstream Products

• 5831-43-6 1,1,2,2-tetrakis(4-methylphenyl)ethylene 
• 40673-57-2 1,1,2,2-tetra(p-tolyl)ethane 
• 16845-02-6 tri-p-tolylmethane 
• 99-94-5 p-Toluic acid 
• 3247-00-5 tris(4-methylphenyl)methanol 
• 859776-87-7 1,2,2,2-tetra-p-tolyl-ethanol 

Relevant articles and documents

Tetraarylethylenes from Diarylmethanones and Hexachlorodisilane: The “Sila-McMurry” Reaction

Hexachlorodisilane reacts with diarylmethanones (aryl=C6H5, 4-MeC6H4, 4-tBuC6H4, 4-ClC6H4, 4-BrC6H4) to furnish the corresponding tetraarylethylenes in good yields. The reductive conversion requires temperatures of about 160 °C and reaction times of 60–72 h. In the initial step, the Lewis-basic carbonyl groups likely generate low-valent [SiCl2] as an analogue of [TiCl2] in the classical McMurry reaction. The coupling sequence further proceeds via benzopinacolones, which have been isolated as key intermediates.

Acid catalysis vs. electron-transfer catalysis via organic cations or cation-radicals as the reactive intermediate. Are these distinctive mechanisms?

Proton transfer to aromatic and olefinic donors (D) leads to the facile interchange of transient carbocations (DH+) and cation-radical (D+.). The same types of cation and cation-radical are reactive intermediates in the acid catalysis and the electron-transfer catalysis of such organic transformations as benzylic coupling, epoxide/pinacol rearrangements and cis-trans isomerization of stilbenes when they are both carried out under otherwise identical reaction conditions. However, the rapid exchange of diamagnetic cations and paramagnetic cation-radicals blurs the traditional view of separate electrophilic and homolytic processes, and rigorous experimental evidence is required to establish whether acid catalysis and electron-transfer catalysis actually represent distinct mechanistic categories. Acta Chemica Scandinavica 1998.

Catalytic epoxidation of hindered olefins with dioxygen. Fast oxygen atom transfer to olefin cation radicals from nitrogen oxides

Hindered olefins are efficiently converted to epoxides by dioxygen at 25°C in dichloromethane containing catalytic amounts of nitrogen oxides (NO2, NO+, NO, etc.). Nitrogen dioxide also effects the direct (stoichiometric) epoxidation of the same hindered olefins. Olefin cation radicals are spectrally identified as the first observable intermediate, and separate experiments confirm the facile transfer of an oxygen atom from nitrogen dioxide to olefin cation radicals to produce epoxides. At low temperature (-78°C), the epoxidation is rapidly initiated by added 1-electron oxidants such as tris(2,4-dibromophenyl)amine cation radical and nitrosonium (NO+). Scheme 3 presents the complete sequence of redox changes that are mediated by the nitrogen oxides in the catalytic conversion of hindered olefins to epoxides via the cation radical. The deliberate irradiation of the charge-transfer absorption band of the corresponding olefin electron donor-acceptor complexes with tetranitromethane also establishes the formation of epoxides to occur via the same reactive pair, i.e., the olefin cation radical and NO2. The mechanistic implication of rapid oxygen atom transfer to olefin cation radicals is underscored in the general consideration of catalytic epoxidations with dioxygen.

Photoinduced electron transfer carbon-carbon bond cleavage of radical cations of carbonyl compounds in solution. 2,4,6-Triphenylpyrylium salt-sensitized oxygenation of aralkyl ketones and aldehydes

Photosensitized electron transfer oxygenation of several aralkyl ketones and aldehydes such as 1,2,2-triphenylethanone and diphenyl- and triphenylethanal has been carried out with 2,4,6-triphenylpyrylium tetrafluoroborate (TPP+BF4-) in dichloromethane. The carbonyl compounds underwent C-C bond cleavage through their cation radicals, generated via electron transfer to the excited singlet state of the pyrylium salt. For example, diphenylethanal afforded benzophenone in 80% yield. Direct evidence for the electron transfer and subsequent formation of a carbocation through C-C bond cleavage was obtained by laser flash photolysis of tetrakis(4-methylphenyl)ethanone in dichloromethane. It is proposed that arylmethyl cations generated by the C-C bond cleavage of the cation radicals undergo electron transfer with pyryl radicals to give arylmethyl radicals, which react with molecular oxygen to afford the final oxygenation products.

Novel reductive couplinog-rearrangement of carbonyl compounds with metal/Lewis acid under irradiation of ultrasonic wave

Novel reductive coupling-rearrangement of carbonyl compounds such as benzophenones with Al or Zn/ AlCl3 in CH3CN under irradiation of ultrasonic wave gave benzopinacolones via epoxides in good yields.

REACTION OF CHLOROSULFONYL ISOCYANATE WITH 1,2-DIOLS: REARRANGEMENT AND FORMATION OF CARBONATES

1,2-Diols, 1a-e, upon reaction with chlorosulfonyl isocyanate (CSI) gave the ketones, 3a-e.Under similar experimental conditions, 1,2-diols, 1f-k, gave carbonyl compounds, 3f-k, carbonates, 6f-k, carboxamides, 7h,i, and the epoxide, 5i.