28550-92-7

Upstream product

• 87655-62-7 tris(4-(tert-butyl)phenyl)methyl bromide 
• 6934-33-4 tris(4-(tert-butyl)phenyl)methanol 
• 3972-65-4 1-bromo-4-tert-butylbenzene 
• 7050-16-0 tris(4-t-butylphenyl)methyl chloride 

Downstream Products

• 27541-51-1 tris(4-(tert-butyl))phenylmethane 
• 38117-54-3 cyclopentadienyl iron(II) dicarbonyl dimer 
• 10170-69-1 dimanganese decacarbonyl 
• 15444-76-5 Mn₂(CO)8(ethyldiphenylphosphine)2 

Relevant academic research and scientific papers

TEMPO-Mediated Catalysis of the Sterically Hindered Hydrogen Atom Transfer Reaction between (C5Ph5)Cr(CO)3H and a Trityl Radical

We have demonstrated the ability of TEMPO to catalyze H· transfer from (C5Ph5)Cr(CO)3H to a trityl radical (tris(p-tert-butylphenyl)methyl radical). We have measured the rate constant and activation parameters for the direct reaction, and for each step in the catalytic process: H· transfer from (C5Ph5)Cr(CO)3H to TEMPO and H· transfer from TEMPO-H to the trityl radical. We have compared the measured rate constants with the differences in bond strength, and with the changes in the Global Electrophilicity Index determined with high accuracy for each radical using state of the art quantum chemical methods. We conclude that neither is a major factor in determining the rates of these H· transfer reactions and that the effectiveness of TEMPO as a catalyst is largely the result of its relative lack of steric congestion compared to the trityl radical.

Direct observation of oxygen rebound with an iron-hydroxide complex

The rebound mechanism for alkane hydroxylation was invoked over 40 years ago to help explain reactivity patterns in cytochrome P450, and subsequently has been used to provide insight into a range of biological and synthetic systems. Efforts to model the rebound reaction in a synthetic system have been unsuccessful, in part because of the challenge in preparing a suitable metalhydroxide complex at the correct oxidation level. Herein we report the synthesis of such a complex. The reaction of this species with a series of substituted radicals allows for the direct interrogation of the rebound process, providing insight into this uniformly invoked, but previously unobserved process.

Evidence for formation of a Co-H bond from (H2O) 2Co(dmgBF2)2 under H2: Application to radical cyclizations

Under H2, the radical cyclization of appropriate dienes can be catalyzed by cobaloximes. H can be abstracted from an intermediate (presumably a cobalt hydride) by trityl radicals (Ar3C) or by TEMPO. The rate-determining step in these reactions is the uptake of H2, which is second order in cobalt and first order in hydrogen; the third-order rate constant is 106(3) M-2As-1.

Relative Rates of H? Transfer from Transition-Metal Hydrides to Trityl Radicals

The tris(p-tert-butylphenyl)methyl radical can be made in quantitative yield by treating a toluene solution of the corresponding bromide with copper powder. This radical abstracts H? from all the common transition-metal hydrides but does not stick to the resulting metalloradicals, so that the latter form metal-metal-bonded dimers. The rates of these H? transfer reactions have been measured directly in a stopped-flow apparatus. At 25°C the H? transfer rate constants vary from -1 s-1 for HMn(CO)4(PEtPh2) to 12000 M-1 s-1 for HFe(CO)2Cp. As a whole these rate constants show that the rates of these H? transfer reactions are substantially influenced by steric factors as well as by bond strengths.

Sterically Hindered Free Radicals, XIX. - Stable 4,4',4''-Trisubstituted Triphenylmethyl Radicals

The title radicals (4-R-C6H4)3C. (1), R = F, Cl, Ph, OMe, NO2, tBu, OEt, SMe, CN, CF3, have been prepared, the latter four for the first time, and the ESR spectra have been recorded. aoH, amH, and as

Preparation and Characterization of Some Pentaarylethyls

The reaction of triphenylmethylsodium with dichlorodiphenylmethane does not give pentaphenylethyl as previously reported, but when the anion reacts with 9,9-dichlorofluorene, it does form the reported 9-tritylfluorenyl radical which has been characterized by ESR spectroscopy.The radical is better prepared by oxidation of the anion of 9-tritylfluorene.The 9-tritylfluorenyl radical reacts with traces of oxygen to give triphenylmethyl and fluorenone.With light it forms triphenylmethyl and fluorenylidene.The latter was established by photolyzing 9-diazofluorene in the presence of triphenylmethyl with the generation of 9-tritylfluorenyl.Small yields of the persistent pentakis(p-tert-butylphenyl)ethyl radical have been prepared, and it is propable that pentaphenylethyl has also.