Base-Promoted Consecutive Enolate Addition Reaction of [60]Fullerene with Ketones

Abstract

[60]Fullerene derivatives with novel 1,4,9,25- and 1,4,9,12-configurations were obtained by reactions of C60 with aliphatic ketones and benzyl bromide under basic conditions. The structures of the products were determined by X-ray single-crystal diffraction and spectroscopic characterization. The reactions were rationalized by a monoenolate addition experiment and in situ vis-NIR spectroscopy.

Palladium-Catalyzed Heteroannulation of Indole-1-carboxamides with [60]Fullerene and Subsequent Electrochemical Transformations

“…The 1,2,3,4-addition pattern for 3a and 1,2,3,16-addition pattern for 3b and 3c were confirmed by their characteristic UV–vis spectra, which were similar to the previously reported ones. ,− However, the UV–vis spectrum of 3d was different from that of a 1,2,3,16-adduct. Product 3d was a 1,4,9,25-adduct, as resolved by single-crystal X-ray diffraction analysis (CCDC 1936161), and the UV–vis spectrum of 3d was similar to those of the previously reported 1,4,9,25-adducts . It should be noted that the formation of 3a , 3b , 3c , and 3d was accompanied by the migration of tetrahydro­pyrimidone six-membered cyclic ring from the original [6,6]-junction to a [5,6]-junction of C 60 .…”

“…Similarly, the 1,2,3,16-adduct 3c could be obtained in 41% yield by reacting the dianion 2a 2– with 10 equiv of benzoyl chloride in the presence of 20 equiv of NaH and then quenched with 3 equiv of TFA at 0 °C. Intriguingly, we successfully achieved the synthesis of 1,4,9,25-adduct 3d containing two benzyl groups as addends in 53% yield by using 10 equiv of benzyl bromide and 20 equiv of NaH at 40 °C for 12 h. This is the first example for the electrochemical synthesis of a 1,4,9,25-adduct . The regioselective formation of 3a – d was governed by the charge distribution of 2a 2– , the size of the approaching addends, and the stability of the products. − , …”

“…Intriguingly, we successfully achieved the synthesis of 1,4,9,25-adduct 3d containing two benzyl groups as addends in 53% yield by using 10 equiv of benzyl bromide and 20 equiv of NaH at 40 °C for 12 h. This is the first example for the electrochemical synthesis of a 1,4,9,25-adduct. 12 The regioselective formation of 3a−d was governed by the charge distribution of 2a 2− , the size of the approaching addends, and the stability of the products. 11a−c,12 The 1,2,3,4-addition pattern for 3a and 1,2,3,16-addition pattern for 3b and 3c were confirmed by their characteristic UV−vis spectra, which were similar to the previously reported ones.…”

“…Proposed Mechanism analysis (CCDC 1936161), and the UV−vis spectrum of 3d was similar to those of the previously reported 1,4,9,25adducts. 12 It should be noted that the formation of 3a, 3b, 3c, and 3d was accompanied by the migration of tetrahydropyrimidone six-membered cyclic ring from the original [6,6]junction to a [5,6]-junction of C 60 . 11 The electrochemical properties of 3a−d along with C 60 have also been investigated by CV (see the Supporting Information).…”

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

“…We have reported the OH – -promoted reactions of [60]­fullerene with ketones (cyclohexanone, cyclopentanone, and 3-pentanone) and BnBr (benzyl bromide), where C 60 derivatives with the 1,4,9,25-configuration and a cyclopentanone ring subunit with a closed C 60 [5,6]-bond (Figure c) were obtained via the consecutive enolate additions to C 60 . However, the analogous reaction of C 60 with acetone, the most conventional ketone, was different with the generation of a new type of products that were unable to be identified at that time.…”