105804-97-5Relevant articles and documents
Mechanistic investigation of oxidative Mannich reaction with tert-butyl hydroperoxide. the role of transition metal salt
Ratnikov, Maxim O.,Doyle, Michael P.
supporting information, p. 1549 - 1557 (2013/03/14)
A general mechanism is proposed for transition metal-catalyzed oxidative Mannich reactions of N,N-dialkylanilines with tert-butyl hydroperoxide (TBHP) as the oxidant. The mechanism consists of a rate-determining single electron transfer (SET) that is uniform from 4-methoxy- to 4-cyano-N,N-dimethylanilines. The tert-butylperoxy radical is the major oxidant in the rate-determining SET step that is followed by competing backward SET and irreversible heterolytic cleavage of the carbon-hydrogen bond at the α-position to nitrogen. A second SET completes the conversion of N,N-dimethylaniline to an iminium ion that is subsequently trapped by the nucleophilic solvent or the oxidant prior to formation of the Mannich adduct. The general role of Rh2(cap) 4, RuCl2(PPh3)3, CuBr, FeCl 3, and Co(OAc)2 in N,N-dialkylaniline oxidations by T-HYDRO is to initiate the conversion of TBHP to tert-butylperoxy radicals. A second pathway, involving O2 as the oxidant, exists for copper, iron, and cobalt salts. Results from linear free-energy relationship (LFER) analyses, kinetic and product isotope effects (KIE and PIE), and radical trap experiments of N,N-dimethylaniline oxidation by T-HYDRO in the presence of transition metal catalysts are discussed. Kinetic studies of the oxidative Mannich reaction in methanol and toluene are also reported.
The iron(II)/reductant (DH2)-induced activation of dioxygen for the demethylation of N-methylanilines: Reaction mimic for the cytochrome P- 450/reductase system
Hage,Schnelten,Sawyer
, p. 821 - 824 (2007/10/03)
Several iron(II) complexes [Fe(II)L(x); Fe(II)(DPAH)2 (DPAH2 = 2,6- dicarboxyl pyridine), Fe(II)(PA)2 (PAH = picolinic acid) and Fe(II)(bpy)2/2+ (bpy = 2,2'-bipyridine)] in combination with a reductant [DH2; PhNHNHPh (mimic of dihydroflavin)] catalytically activate O2 (1 atm) for the demethylation of N-methylanilines [PhN(CH3)2, PhNH(CH3)]. This chemistry, which appears to involve a Fenton-like intermediate [L(x)Fe(IV)OOH(DH) (1c)], mimics that of the cytochrome P-450 monooxygenase/reductase proteins.
