42732-53-6Relevant articles and documents
The rearrangement of the trityloxy radical: Sherlock holmes' most recent case
Bucher, Goetz
body text, p. 6934 - 6935 (2010/12/18)
Reopening the case: One hundred years after Wieland's original publication, the rearrangement of the trityloxy radical was studied by K. Ingold et al., who investigated the title reaction with the logical reasoning and intellectual prowess of true detecti
Isomerization of triphenylmethoxyl: The wieland free-radical rearrangement revisited a century later
DiLabio, Gino A.,Ingold,Lin, Shuqiong,Litwinienko, Grzegorz,Mozenson, Olga,Mulder, Peter,Tidwell, Thomas T.
supporting information; experimental part, p. 5982 - 5985 (2010/10/02)
(Figure Presented) Old wisdom teaches a new lesson : The rate constant for the isomerization of thermally generated triphenylmethoxyl to Ph 2(PhO)C has been determined both experimentally and by DFT calculations (see scheme), and the results vindicated Wieland's 1911 observations and conclusions-in contrast to photochemically based findings.
Thermolysis of N-tetramethylpiperidinyl triphenylacetate: Homolytic fragmentation of a TEMPO ester
Henry-Riyad, Huda,Tidwell, Thomas T.
, p. 559 - 563 (2007/10/03)
Thermolysis of N-tetramethylpiperidinyl triphenylacetate (7, Ph 3CCO2T, T = 2,2,6,6-tetramethylpiperidinyl) in benzene at 146 °C leads to the formation of triphenylmethane (Ph3CH, 80%), tetramethylpiperidine (TH, 91%), and tetraphenylmethane (Ph4C, 9%). First-order rate constants for the decomposition at 132.8 and 150.0 °C were 2.20 × 10-6 and 2.88 × 10-5 s-1, respectively. In benzene-d6 solvent the triphenylmethane was formed as Ph3CD to the extent of 20%, as determined by 1H NMR and mass spectrometry. The results are interpreted as showing that Ph 3CCC2T undergoes thermolysis by concerted two-bond scission with formation of Ph3C., tetramethylpiperidinyl radicals and CO2. The formation of Ph4C occurs by addition of Ph3C. to benzene, followed by hydrogen atom abstraction from the resulting adduct. Calculations using DFT methods at the B3LYP/6-311++G** level were used to elucidate the bond fission of HCO2T (2), and indicate that cleavage to HCO2. and T. is favored by 7.8 kcal mol-1 relative to cleavage to HC(·)=O and TO., in agreement with the experimental results. Copyright
Neophyl-like Rearrangement of Alkoxy Radicals: Direct Detection of a Bridged Intermediate by Time-Resolved Absorption Spectroscopy
Falvey, Daniel E.,Khambatta, Binaifer S.,Schuster, Gary B.
, p. 1056 - 1059 (2007/10/02)
The neophyl-like rearrangment of alkoxy radicals was examinde by means of picosecond time scale absorption spectroscopy.The triphenylmethoxy radical (Ph3CO.) rearranges to form the α-phenoxydiphenylmethyl radical (Ph2COPh.) with a rate constant greater than 5 x 1010 s-.The rearrangment of 1,1-diphenylethoxy radical (PhCH3CO.) was also examined.In acetonitrile solution, an intermediate is formed in less than 17 ps and then decays with a lifetime of 312 ns.It is proposed that this intermediate is a brigded spirooctadiene-type radical.
