Large Substituent Effect on the Photochemical Rearrangement of 1,6-(N-Aryl)aza-[60]fulleroids to 1,2-(N-Arylaziridino)-[60]fullerenes

Abstract

Large substituent effects were observed in the rates and reaction mechanisms of the photochemical rearrangement of N-arylaza-[60]fulleroid 1 to N-arylaziridino-[60]fullerene 2, in which the difference of the rates between the fastest and the slowest (>2160-fold) was attained only by changing the aryl group from 1-naphthyl to 2-naphthyl. The decreasing order of the reaction rates in relation to the substituents was 1-naphthyl (1b) > 1-pyrenyl (1d) > phenyl (1a) > 2-naphthyl (1c). The reactions proceeded via triplet states of the fulleroids and a triplet sensitization of the reaction by rearranged product 2b was observed in the case of 1b. The slow reactions of 1a,c were interpretated by the participation of charge-separated species in the excited triplet states, which was supported by nanosecond transient absorption spectra.

Selective cycloaddition of aryl azides to fullerene C60 in the presence of Cu(OTf)2

“…The presence of an sp 3 -carbon signal at δ C 83.63 ppm unambiguously indicated the formation of 6,6-closed cycloadduct. Carbon nuclei in the N-phenyl substituent resonated at δ C 121.55, 124.37, 129.28, and 145.62 ppm, and the fullerene moiety gave rise to 16 signals in the region δ C 140-145 ppm, in full agreement with the data of [10,12].…”

Preparation and Characterization of Sulfonyl‐Azafulleroid and Sulfonylaziridino‐Fullerene Derivatives

“…Ouchi, Ito and co-workers also observed a large substituent effect on the photochemical rearrangement of N-aryl-aza [60]fulleroids. [25] In contrast to C 60 monofunctionalization of C 70 leads to mixtures of regioisomers due to lower symmetry and to differences in reactivity between the various double bonds. There are each four different [6,6] (IϪIV) and [5,6] ring fusions (VϪVIII) (Scheme 3).…”

Notably Enhanced Reactivity of the Fulleroid anti‐Bredt Double Bond in Diels–Alder Reactions

“…[10] However, very little is known about the reactions of fulleroids, probably because of the limited synthetic methods using unstable diazoalkanes as well as their thermal and photochemical lability. [11] We have noticed that fulleroids [12] are easily separated from other fullerene derivatives if polar substituents are introduced, and they behave as a reactive intermediates on account of the reactive bridgehead double bonds. [13,14] In our preliminary study, [14] we have also found that some fulleroids show highly regioselective Diels-Alder (DA) reaction with 2,3-dimethyl-1,3-butadiene compared with the nonregioselective reaction with cyclopentadiene.…”