Minisci aerobic alcohol oxidation

Minisci reported the first nitroxyl-catalyzed aerobic alcohol oxidation in the presence of precursors in 2001 (Scheme 15.7a) [28]. The optimal reaction conditions included a combination of catalytic Mn(N03)2 and Co(N03)2 with TEMPO (10 mol%) under 1 atm of O2. The authors demonstrated that Mn(NOg)2, Co(N03)2, and Cu(N03)2 were independently effective catalysts, implicating the nitrate anion as an important contributor to the reaction. Primary and secondary benzylic alcohols, primary allylic alcohols, and primary and secondary aliphatic alcohols were oxidized to the corresponding aldehydes/ketones in excellent yields. 

I 15 NO Cocatalysts for Aerobic Oxidation Reactions Application to Alcohol Oxidation (a) Minisci et al. [28] 02/NOx/TEMPO... 

Aerobic Oxidation of Alcohols 385 Francesco Minisci and Ombretta Porta... 

F. Minisci, C. Punta, F. Recupero, F. Fontana, G. F. Pedulli, A new, highly selective synthesis of aromatic aldehydes by aerobic free-radical oxidation of benzylpic alcohols, catalysed by N-hydroxyphtalimide under mild conditions. Polar and enthalpic effects, Chem. Commum. (2002) 68. 

F. Minisci, F. Recupero, A. Cecchetto, C. Gambarotti, C. Punta, R. Faletti, R. Paganelli, G. F. Pedulli, Mechanism of the aerobic oxidation of alcohols to aldehydes and ketones, catalysed under mild conditions by persistent and non-persistent nitroxyl radicals and transition metal salts-polar, enthalpic and captodative effects, Eur. J. Org. Chem. (2004) 109. 

TEMPO, polystyrene-supported TEMPO, sol-gel TEMPO, PEG-TEMPO, supported oxammoium salts, etc.). These catalysts have shown good activity and selectivity, and were also readily recyclable. The aerobic oxidation of alcohols with supported TEMPO employing oxygen as co-oxidant has been explored [19k, 191, 20], either in the presence of Co(N03)2 and Mn(N03)2 (Minisci s conditions) or in the presence of Cu(II), giving interesting results. 

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