N -Alkylation of Fulleropyrrolidines by Aminomethylation Reaction of Ketones/Arylboronic Acids

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

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.

Facile access to amino-substituted cyclopentafullerenes: novel reaction of [60]fullerene with β-substituted propionaldehydes and secondary amines in the absence/presence of magnesium perchlorate

A series of scarce amino-substituted cyclopentafullerenes instead of the expected N-alkyl-2,5-disubstituted fulleropyrrolidines were synthesized in moderate to excellent yields via the simple one-step reaction of [60]fullerene with cheap and easily available β-substituted propionaldehydes and secondary amines in the absence/presence of magnesium perchlorate. The in situ generation of allylic amines from β-substituted propionaldehydes and secondary amines played a crucial role in the successful preparation of amino-substituted cyclopentafullerenes without additional carbons. With the addition of magnesium perchlorate, secondary amines containing ethyl group(s) could produce novel amino-substituted cyclopentafullerenes with two additional carbons. All the obtained cyclopentafullerenes displayed high stereoselectivity with cis isomers as the exclusive or major products. Plausible reaction mechanisms are proposed to elucidate the above-mentioned reaction process.

Stereoselective synthesis of amino-substituted cyclopentafullerenes promoted by magnesium perchlorate/ferric perchlorate

A facile one-step reaction of [60]fullerene with cinnamaldehydes and amines promoted by magnesium perchlorate/ferric perchlorate under air conditions afforded a series of rare amino-substituted cyclopentafullerenes in moderate to good yields. Stereoselectivity was readily achieved. Secondary amines exclusively produced N,N-disubstituted cyclopentafullerenes as cis isomers, while arylamines gave N-monosubstituted cyclopentafullerenes with a preference of cis isomers as major products. N-Monosubstituted cyclopentafullerenes could be further converted into other scarce cyclopentafullerenes in the presence of acid chloride or paraformaldehyde. A possible reaction pathway was proposed to elucidate the formation of amino-substituted cyclopentafullerenes.

Metal-free synthesis of fulleropyrrolidin-2-ols: a novel reaction of [60]fullerene with amines and 2,2-disubstituted acetaldehydes

The reaction of [60]fullerene with amines and 2,2-disubstituted acetaldehydes in the absence of metal salts afforded a series of novel fulleropyrrolidin-2-ols in moderate yields.