Manganese(III) acetate-mediated synthesis of N-substituted fulleropyrrolines via the reaction of [60]fullerene with α-monosubstituted acetaldehydes and primary amines.

Abstract

The simple one-step reaction of [60]fullerene with α-monosubstituted acetaldehydes and primary amines in the presence of Mn(OAc)3·2H2O under air conditions afforded a series of novel N-substituted fulleropyrrolines with trisubstituted CC bonds in moderate to good yields. The addition of Mn(OAc)3·2H2O played a crucial role in the successful synthesis of N-aryl fulleropyrrolines with trisubstituted CC bonds, which would be extremely difficult to prepare by known methods as a result of the decreased nucleophilicity of arylamines due to the p-π conjugation effect. Intriguingly, arylamines displayed abnormally higher reactivity as compared with non-arylamines in the current reaction system by the observation of obviously decreased equivalent of Mn(OAc)3·2H2O, higher product yields, and lower reaction temperature probably due to the radical reaction mechanism initiated by Mn(OAc)3·2H2O. On the basis of experimental observations, a plausible formation pathway for N-substituted fulleropyrrolines with trisubstituted CC bonds was proposed to elucidate the above-mentioned reaction process.