56075-34-4Relevant academic research and scientific papers
Amination of benzylic C-H bonds by aryl azides catalysed by Co(II)(porphyrin) complexes. A new reaction leading to secondary amines and imines
Cenini,Gallo,Penoni,Ragaini,Tollari
, p. 2265 - 2266 (2000)
Co(II)(porphyrin) complexes catalyse the reaction of aromatic azides, ArN3, with hydrocarbons containing a benzylic group, R1R2R3CH, to give the corresponding amines, R1R2R3C-NHAr. When at least one of the R1-R3 substituents is hydrogen, the catalytic reaction proceeds further to give the imines R1R2C=NAr in good yields.
Amination of benzylic C-H bonds by arylazides catalyzed by CoII-porphyrin complexes: A synthetic and mechanistic study
Ragaini, Fabio,Penoni, Andrea,Gallo, Emma,Tollari, Stefano,Li Gotti, Claudia,Lapadula, Marta,Mangioni, Enrica,Cenini, Sergio
, p. 249 - 259 (2007/10/03)
CoII-porphyrin complexes catalyze the reaction of aromatic azides (ArN3) with hydrocarbons that contain a benzylic group (ArR1R2CH) to give the corresponding amines (ArR1R2C-HAr). When at least one of the R substituents is hydrogen, the catalytic reaction proceeds further to give the imine ArRC=NAr in good yields. The reaction mechanism has been investigated. The reaction proceeds through a reversible coordination of the arylazide to the ConII-porphyrin complex. This unstable adduct can either react with the hydrocarbon in the rate-determining step or decompose by a unimolecular mechanism to afford a putative nitrene complex, which reacts with more azide, but not with the hydrocarbon, to afford the byproduct diaryldiazene. The kinetics of the catalytic reaction have been investigated for a range of azides and substituted toluenes. Arvlazides with electron-withdrawing substituents react at a faster rate and a good correlation is found between the log(k) and the Taft parameters. On the other hand, an excellent correlation between the logarithm of the rate for substituted toluenes relative to that of toluene and a radical parameter (σJJ) alone was found, with no significant contribution by polar parameters. An explanation has been proposed for this anomalous effect and for the very high isotopic effect (kH/kD= 14) found.
