6002-32-0Relevant academic research and scientific papers
The Reaction of Triphenylmethyl Halides with Triphenylphosphine in Cumene and tert-Butylbenzene
Huszthy, Peter,Kajtar-Peredy, Maria,Lempert, Karoly,Hegedues-Vajda, Judit
, p. 347 - 354 (2007/10/02)
Reactions of triphenylmethyl bromide and chloride with triphenylphosphine at elevated temperatures under argon furnish mixtures of the reductive dehalogenation product triphenylmethane and the tele substitution products 2a or 2b, the ratio of the products depending on the reaction conditions.The formation of triphenylmethane indicates that the reaction is, at least partly, initiated by halophilic attack or by single-electron transfer (SET) from the phosphine .The resulting triphenylmethanide anions or triphenylmethyl radicals would then be converted into triphenylmethane by proton or hydrogen abstraction or recombine with their phosphorus containing co-products to yield the tele substitution products .The latter could, at least partly, also be formed via eqn. (1a).Exclusive operation of the SET initiated mechanisms of formation of both products has been proved by combination of trapping studies with molecular oxygen and proof of the absence of triphenylmethanide anions from the reaction mixture.
The Reaction of Triphenylmethyl Halides with Tributylphosphine and Tributylamine in Apolar Solvents
Huszthy, Peter,Izso, (nee Gergacz) Gyoengyi,Lempert, Karoly,Kajtar-Peredy, Maria,Gyoer, Miklos,et al.
, p. 1513 - 1520 (2007/10/02)
Triphenylmethyl bromide (1a) and chloride (1b) react with tributylphosphine and tributylamine in aromatic hydrocarbons by single electron transfer.The triphenylmethyl radicals produced (which may be detected by e.s.r. spectroscopy) abstract hydrogen from the solvent or the radical cations of the reagents to give triphenylmethane (1c), and are trapped by oxygen to give triphenylmethylperoxy radicals and subsequently benzophenone, triphenylmethanol (1d), and phenol.Tributylphosphine and tributylamine may act as hydrogen donors in the hydrogen-transfer processes involved in the formation of these oxygenation products.The halides (1a, b) and tributylphosphine furnish, in the absence of oxygen, in addition to triphenylmethane (1c) the tele substitution products (2a) and (2b), respectively.There is some evidence that the phosphonium salt (2a) is formed by an S'ET process, i.e. out-of-cage recombination of triphenylmethyl radicals and tributylphosphine radical cations or tributylphosphine.
