Reactions of [60]Fullerene with Acetone under Basic Condition: Nucleophilic Ring Opening of the [5,6]-Cyclopropane in C₆₀ and Formation of the Substituted Methano[60]Fulleroids

Abstract

The reactions of C60 with acetone were carried out under basic condition in the presence of 1.0 M TBAOH (tetra-n-butylammonium hydroxide) methanol solution and ArCH2Br (Ar = Ph or o-BrPh), where methano[60]­fulleroids with a novel 1,1,4,­9,9,25-configuration were obtained and structurally characterized by single crystal diffraction. The product was formed via the ring-opening reaction of the [5,6]-cyclopropane by the nucleophilic addition of MeO–, which is different from the reactions of other ketones reported previously.

Retro Baeyer–Villiger reaction: thermal conversion of the [60]fullerene-fused lactones to ketones

“…of PhCH 2 Br at 50 °C for 6 h, we obtained two ring-opened bis-benzylated peroxyesters 3a (29% yield) and 4a (25% yield), rather than the expected keto analogues. 6,18 The oxygen atoms in the products should come from a trace of O 2 in the system, 19 and the selectivity for 3a and 4a was comparable to that for 6 and 7 (Fig. 1) obtained from the C 60 -fused lactone reported earlier by us.…”

A regioselective step-by-step C60Cl6 functionalization approach affords a novel family of C60Ar5Th′Th′′H fullerene derivatives with promising antiviral properties

“…S47, ESI †). All of them either do not have destabilizing [5,6] double bonds or have only one such bond in their structure (except those in cyclopentadienyl fragment). Relative energies for six different isomers of C 1 -C 60 H 8 were calculated (Table S1, ESI †), and three structures (A, B and E) with the lowest values were chosen for further consideration.…”

“…Electrophylic protonation of a CQC double bond in the fullerene derivatives C 1 -C 60 Ar 5 Th 0 is followed by the attack of the electron-rich thiophene molecule from the less sterically hindered position. Finally, the deprotonation of the intermediate leads to the formation of the fullerene derivative C 1 -C 60 Ar 5 Th 0 Th 00 H. Despite the presence of a highly reactive [5,6] double bond in the molecular structure of C 1 -C 60 Ar 5 Th 0 precursors, its involvement becomes unfavorable in the case of bulky reactants due to the specific hindrance effects. Therefore, an unprecedented addition pattern is realized due to the regioselective addition of thiophene derivative to [6,6] double bond in C 1 -C 60 Ar 5 Th 0 compounds.…”

“…2,4 To the best of our knowledge, the only examples of the synthesis of fullerene derivatives bearing three types of functional addends on the cage in a regioselective manner are based on the reaction of the C 60 Ph 4 (CH 2 SiMe 3 )H with [CpFe(CO) 2 ] 2 5 and the reaction of C 60 with acetone under basic conditions coupled with the intermediate quenching with ArBr. 6 Both these reactions have a limited synthetic scope and could hardly be used for introduction of different labile functional groups ( e.g. COOH, COOR, etc. )…”