Highly selective hydrogenation of amides catalysed by a molybdenum pincer complex: Scope and mechanism
A series of molybdenum pincer complexes has been shown for the first time to be active in the catalytic hydrogenation of amides. Among the tested catalysts, Mo-1a proved to be particularly well suited for the selective C-N hydrogenolysis of N-methylated formanilides. Notably, high chemoselectivity was observed in the presence of certain reducible groups including even other amides. The general catalytic performance as well as selectivity issues could be rationalized taking an anionic Mo(0) as the active species. The interplay between the amide CO reduction and the catalyst poisoning by primary amides accounts for the selective hydrogenation of N-methylated formanilides. The catalyst resting state was found to be a Mo-alkoxo complex formed by reaction with the alcohol product. This species plays two opposed roles-it facilitates the protolytic cleavage of the C-N bond but it encumbers the activation of hydrogen.
Mono-N-methylation of anilines with methanol catalyzed by a manganese pincer-complex
The selective mono-N-methylation of anilines derivatives was achieved under mild conditions using inexpensive methanol as C1 source. Under hydrogen borrowing conditions, using a tridentate PN3P manganese pre-catalyst (5?mol%), a catalytic amount of base (20?mol%), for 24?h at 120?°C, a large variety of anilines derivatives was methylated in good to excellent yield. Mechanistic investigations allowed us to isolate and characterize by X-ray diffraction studies a de-aromatized manganese intermediate.
Additions of azomethine ylides to fullerene C60 assisted by a removable anchor
The addition of nitrile oxides to [60]fullerene, leading to isoxazolinofullerenes, can be reversed using reducing agents such as Mo(CO)6 or DIBALH. Thus, this reaction can be used; in principle, for protection/deprotection of [60]fullerene or f
Da Ros, Tatiana,Prato, Maurizio,Lucchini, Vittorio
p. 4289 - 4297
(2007/10/03)
Cycloaddition of nitrile oxides to [60]fullerene
The addition of nitrile oxides to [60]fullerene is examined and it is found that the reaction products regenerate [60]fullerene under relatively mild conditions; the result is potentially useful for better control of fullerene functionalization.
Da Ros, Tatiana,Prato, Maurizio,Novello, Fabiola,Maggini, Michele,De Amici, Marco,De Micheli, Carlo
p. 59 - 60
(2007/10/03)
More Articles about upstream products of 1142-18-3