Photooxidation and Intramolecular Reaction of the Anthryl Moiety in [60]Fullerene Derivatives

Abstract

Anthracene groups have been linked to [60]fullerene by the [3+2] cycloaddition of the corresponding nitrile oxides or by esterification with a [60]fullerenol. The anthryl groups of the fullerene derivatives 3, 7, and 10 react readily with singlet oxygen to form the 9,10‐epidioxides 4, 8, and 12 under photooxidation. The anthryl moiety of the fullerenol ester 10 also reacts with the fullerene skeleton to form the stable intramolecular Diels‐Alder adduct 11.

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“…22 Similarly the band structures of several one-dimensional C 36 polymers, which are shown to be semi-conductors with finite energy gaps, have been calculated using the self-consistent field crystal orbital method. 23 The 13 C NMR spectra of [60]-, [70]-, [72]-, [74]-, [76]-and [78]-fullerenes have been predicted using density functional theory and there is good agreement with the experimental data. 24 The formation of a non-classical fullerene incorporating a fourmembered ring in the cage structure (Fig.…”

“…77 The addition of nitrile oxides bearing anthracene groups results in the formation of isoxazole derivatives in which the anthryl groups readily undergo reaction with singlet oxygen to produce 9,10-epidioxides. 78 In addition, the substituent effects on the redox and photoinduced electron transfer properties of isoxazolofullerenes have been systematically investigated. 79 Modification of the regioselectivity in cycloadditions of azomethine ylides to [70]fullerene can be achieved by the use of microwave irradiation so that the 5,6-isomer becomes the major reaction product instead of the more usual 1,2-regioisomer.…”

First enantiomerically pure C70-adducts with a non-inherently chiral addition pattern

“…38,39 The choice of the proper protecting group was crucial for the later cleavage, 40 particularly because fullerene-fused isoxazolines are known to be rather inert and do not show the typical reactivity of isoxazolines. 28,41,42 The resulting ester (S)-3 was reduced with DIBAL-H to the corresponding aldehyde (S)-4, 43 which was then transformed with hydroxylamine into oxime (S)-5, obtained as a mixture of (E)-and (Z)-isomers. 32 This mixture was converted to hydroximoyl chloride (S)-6.…”

Cycloadditions

“…Isoxazoline derivatives of C 60 such as 250 (Scheme 4.40) are accessible by 1,3-dipolar cycloadditions of nitrile oxides to [6,6] double bonds of the fullerene [2, 278,[291][292][293][294][295][296][297][298][299][300][301][302][303][304][305]. The nitrile oxides 249 with R = methyl, ethyl, ethoxycarbonyl and anthryl are generated in situ from the corresponding nitroalkane, phenyl isocyanate and triethylamine.…”

“…Isoxazolines of C 60 and C 70 [293][294][295] with R = Ph, alkyl, 4-C 6 H 4 OCH 3, 4-C 6 H 4 CHO, amino acid [305], dialkoxyphosphoryl [296,297] or ferrocene [298] have been synthesized in ca. Hydroxymoyl chlorides are accessible by the reaction of aldoximes with chlorinating agents such as NCS (N-chlorosuccinimide).…”