N-Arylation of Pyrrolidino[3′,4′:1,2][60]fullerene: Synthesis under Solvent-Free Conditions and Electrochemistry of New C60–Acceptor Dyads

Abstract

Several pyrrolidinofullerenes were N‐arylated by phase‐transfer catalysis in the absence of solvent. The electrochemical behaviour of the novel C60–acceptor dyads was studied by cyclic voltammetry which showed that the nitro groups on the N‐phenyl ring have a strong influence on the reduction potential values. Theoretical calculations at the semiempirical PM3 level fully support the experimental redox potential values.

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

“…Further derivatization of N-unsubstituted fulleropyrrolidines by the transformation of their NH groups provides a viable way for the preparation of N-substituted fulleropyrrolidines. However, the basicity of fulleropyrrolidines has been found to drop several orders of magnitude than that of the corresponding pyrrolidines [7] and thus led to the great difficulty in further derivatization of fulleropyrrolidines. To date, the derivatization of fulleropyrrolidines has been mainly conducted by using either reactants with high reactivity including 1chloro-2,4-dinitrobenzene, [7] isocyanates, [6a,8a] and acid chlorides [6a,8b] or harsh reaction conditions such as microwave irradiation.…”

“…Fulleropyrrolidines are a kind of pyrrolidine‐containing fullerene derivatives and have promising applications as a source in designing and synthesizing new materials and biologically active compounds . The best‐known Prato reaction along with the newly‐developed reaction based on aldehydes and amines are two main methods for the preparation of fulleropyrrolidines.…”

“…However, the basicity of fulleropyrrolidines has been found to drop several orders of magnitude than that of the corresponding pyrrolidines and thus led to the great difficulty in further derivatization of fulleropyrrolidines. To date, the derivatization of fulleropyrrolidines has been mainly conducted by using either reactants with high reactivity including 1‐chloro‐2,4‐dinitrobenzene, isocyanates,, and acid chlorides, or harsh reaction conditions such as microwave irradiation . The synthesis of N ‐substituted fulleropyrrolidines by employing reactants with relatively lower reactivity under mild conditions is still seldom reported .…”

A faux hawk fullerene with PCBM-like properties

“…[61][62][63][64][65] However, there is still controversy about whether a true Meisenheimer 69 intermediate is formed (even if it cannot be detected spectroscopically) [70][71][72][73][74][75][76] or whether the reaction involves a single Meisenheimer-like transition state. [77][78][79][80] Reactions of C 60 R À carbanions with electrophilic substrates EX to form new C 60 (E)R species and X À are well known, 22,81,82 but to our knowledge there is no previous example of an S N Ar reaction involving a fullerene cage carbanion (i.e., not including examples such as the negatively-charged N atom of a deprotonated cyclo-pyrrolidinofullerene undergoing an intermolecular S N Ar reaction with an aryl chloride 83 ), let alone an intramolecular S N Ar reaction of a fullerene cage carbanion attacking an Ar-F bond. Therefore, we decided to test the intramolecular S N Ar hypothesis for the observed transformation [1 À H] À / 2 + F À by determining DFT-optimized structures and relative energies for 1 and 2 as well as for three different states of [1 À H] À .…”

Cycloadditions

“…Further side-chain chemistry can be carried out either at one of the side chains attached to the five-membered ring [228][229][230][231][232] or at the pyrrolidine nitrogen [215,224,231,[233][234][235][236][237][238][239]. For example, upon heating 3-triphenylmethyloxazolidin-5-one (210) at reflux for 16 h with C 60 in equimolar amounts, 211 can be isolated in 39% yield [204].…”