Highly selective reactions of C60Cl6 with thiols for the synthesis of functionalized [60]fullerene derivatives

Chlorofullerene C(60)Cl(6) undergoes highly selective reactions with thiols forming compounds C(60)[SR](5)H with high yields. These reactions open up straightforward synthetic routes to many functionalized fullerene derivatives, e.g. water-soluble compounds showing interesting biological activities.     

Facile preparation of amine and amino acid adducts of [60]fullerene using chlorofullerene C60Cl6 as a precursor

We report a general synthetic approach to the preparation of highly functionalized amine and amino acid derivatives of [60]fullerene starting from readily available chlorofullerene C(60)Cl(6). The synthesized water-soluble amino acid derivative of C(60) demonstrated pronounced antiviral activity, while the cationic amine-based compound showed strong antibacterial action in vitro.     

Click chemistry for the efficient preparation of functionalized [60]fullerene hexakis-adducts

A Th-symmetrical C60 hexakis-adduct bearing 12 peripheral azide groups has been prepared and used to produce functionalized derivatives by the copper mediated Huisgen 1,3-dipolar cycloaddition of azides and alkynes.     

Chlorofullerene C60Cl6: a precursor for straightforward preparation of highly water-soluble polycarboxylic fullerene derivatives active against HIV

We report for the first time the application of chlorofullerene C60Cl6 as a substrate for straightforward preparation of highly water-soluble fullerene derivatives, promising compounds for investigation of the biological action of fullerenes in vitro and in vivo. Methyl esters of phenylacetic and benzylmalonic acids were used as reagents in the Friedel-Crafts arylation of C60Cl6 that resulted in the corresponding C60(Ar)5Cl compounds with 50-60% yields. The following cleavage of ester groups in phenylacetic and benzylmalonic residues was accomplished almost quantitatively to yield the corresponding fullerene-based acids bearing 5 and 10 carboxylic groups, respectively. The relatively-low solubility of these acids in water can be strongly enhanced (up to 150-200 mg ml(-1)) by their conversion to salts with alkali metal cations. These fullerene salt derivatives showed pronounced anti-HIV action and low toxicity; these two findings point to the necessity for further investigation of the biological properties of the here-reported compounds.     

One-pot sequential synthesis of acetoxylated [60]fullerene derivatives

[reaction: see text] The reaction of [60]fullerene with 4-substituted phenylhydrazine hydrochlorides in refluxing chlorobenzene under aerobic conditions afforded 1-(4-substituted phenyl)-1,2-dihydro[60]fullerenes, which could be subsequently oxidized to 1-acetoxyl-4-aryl-1,4-dihydro[60]fullerenes by manganese(III) acetate dihydrate in one pot. The transformation of ArC(60)-H to ArC(60)-OAc has been realized with Mn(OAc)(3).2H(2)O for the first time.     

Seven-minute synthesis of pure C(s)-C60Cl6 from [60]fullerene and iodine monochloride: first IR, Raman, and mass spectra of 99 mol % C60Cl6

Three previously reported procedures for the synthesis of pure C(s)-C60Cl6 from C60 and ICl dissolved in benzene or 1,2-dichlorobenzene were shown to actually yield complex mixtures of products that contain, at best, 54-80% C(s)-C60Cl6 based on HPLC integrated intensities. MALDI mass spectrometry was used for the first time to identify other components of the reaction mixtures. An improved synthetic procedure was developed for the synthesis of about 150 mg batches of chlorofullerenes containing 90% C(s)-C60Cl6 based on HPLC intensities. The optimum reaction time was decreased from several days to seven minutes. Small amounts of the product were purified by HPLC (toluene eluent) to 99% purity. The pure compound C(s)-C60Cl6 is stable for at least three months as a solvent-free powder at 25 degrees C. The Raman, far-IR, and MALDI mass spectra of pure C(s)-C60Cl6 are reported for the first time. The Raman and far-IR spectra, the first reported for any C60Cl(n) chlorofullerene, were used to carry out a vibrational analysis of C(s)-C60Cl6 at the DFT level of theory.     

Iodo-controlled selective formation of pyrrolidino[60]fullerene and aziridino[60]fullerene from the reaction between C6) and amino acid esters

The reaction between glycine methyl ester and C60 can be effectively controlled by different iodo-reagents. Addition of DIB ((diacetoxyiodo)benzene) yields the 2,5-bismethoxycarbonyl pyrrolidino[60]fullerene under ultrasonic irradiation; whereas addition of DIB-iodine results in the N-methoxycarbonylmethyl aziridino[60]fullerene under ultrasonic irradiation. The reaction of sarcosine methyl ester with C60 is similar to that of glycine methyl ester under these two conditions. Addition of just iodine to a mixture of sarcosine methyl ester and C60 affords the tetra(amino)[60]fullerene epoxide C60(O)((Me)NCH2COOMe)4. Possible mechanisms are discussed.     

Organocatalytic asymmetric multi-component [C+NC+CC] synthesis of highly functionalized pyrrolidine derivatives

The highly chemo- and enantioselective organocatalytic [C+NC+CC] coupling process between aldehydes, dialkyl 2-aminomalonates and α,β-unsaturated aldehydes is presented. The reaction gives access to highly functionalized pyrrolidine derivatives in good yields with >10:1 dr and 90-98% ee.     

Electrophoretic behavior of a highly water-soluble dendro[60]fullerene

The aim of the present study was to develop an analytical method for measuring amounts of a dendro[60]fullerene (DF) which is a highly water-soluble [60]fullerene derivative. We tried to define a straightforward methodology using capillary zone electrophoresis, a method which, to our knowledge, has not yet been used to that purpose. Preliminary assays showed that DF has almost the same mobility than the electroosmotic flow (EOF) but in the opposite direction. Attempts were carried out to reduce the EOF and positive results were obtained by adding hydroxypropylcellulose to the background electrolyte. In order to define optimal operating conditions, a Taguchi experimental plan was used to study simultaneously the effects of the main parameters that are pH, ionic strength, methanol amount and hydroxypropylcellulose concentration. Two parameters are of the utmost importance as to their effect on the migration time and separation efficiecy: pH and ionic strength whose actions are opposite.     

New trifluoromethylated derivatives of [60]fullerene, C60(CF3)n with n = 12 and 14

New isomers of C(60)(CF(3))(12) and C(60)(CF(3))(14) have been isolated from mixtures obtained via reaction of C(60) or S(6)-C(60)(CF(3))(12) with CF(3)I; they were characterized by single crystal XRD study and investigated theoretically by means of DFT calculations.     

Cobalt-catalyzed hydroalkylation of [60]fullerene with active alkyl bromides: selective synthesis of monoalkylated fullerenes

The Co-catalyzed hydroalkylation of C(60) with reactive alkyl bromides 1 (RBr) in the presence of Mn reductant and H(2)O at ambient temperature gave the monoalkylated C(60) (2) in good to high yields. The use of CoLn/Mn/H(2)O under Ar atmosphere is crucial for the success of the present transformation. The reaction most probably proceeds through the Co(0 or I) complex-promoted generation of a radical (R(?)) followed by addition to C(60). This hydroalkylation method was applied to the synthesis of zinc porphyrin attached C(60) (2l), dendrimer attached C(60) (2m), and fullerene dimer (2n), which were not easily available through the previously known methods.     

1,3-dipolar cycloaddition as a method for synthesis of fullerene C60 derivatives containing heterocyclic moieties

We generalize literature data and our own experimental data on using 1,3-dipolar cycloaddition reactions for synthesis of fullerene C₆₀ derivatives containing annelated heterocyclic moieties.M. V. Lomonosov Moscow State University, Moscow 119899, Russia. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 291–297, March, 1998.     

Fullerene-acene chemistry: diastereoselective synthesis of a cis,cis-tris[60]fullerene adduct of 6,8,15,17-tetraphenylheptacene

[structure: see text]. A one-pot, diastereoselective synthesis of a cis,cis-tris[60]fullerene adduct of 6,8,15,17-tetraphenylheptacene has been demonstrated starting from [60]fullerene and 5,7,9,14,16,18-hexahydro-6,8,15,17-tetraphenylheptacene.     

The first synthesis of a methano[60]fullerene with an electron-donating group at the methano-bridge carbon: synthesis and reaction of aminomethano[60]fullerene

[reaction: see text] Aminomethano[60]fullerene was synthesized for the first time as a trifluoromethanesulfonic acid salt by applying the Curtius rearrangement of azidocarbonylmethano[60]fullerene as the key reaction. Aminomethano[60]fullerene thus obtained was found to be able to react with various acyl chlorides to afford the corresponding amides.     

7-氯-[1，2，3，4]-四氢吩嗪-[2，3]-并富勒烯[60]的合成

60富勒烯及其衍生物因其结构的特殊性,在有机超导、分子磁性、有机发光材料、分子器件、非线性光学活性、能量代谢和生物活性等[1]方面表现出独特的性能和潜在的应用前景,是非常活跃的研究领域之一.     

Fullerene-acene chemistry: single-crystal X-ray structures for a [60]fullerene-pentacene monoadduct and a cis-bis[60]fullerene adduct of 6,13-diphenylpentacene

[structure: see text]. Crystal structures of the cis-bis[60]fullerene adduct of 6,13-diphenylpentacene (with the closest carbon atoms on adjacent fullerenes only 3.065(8) angstroms apart) and the [60]fullerene-pentacene monoadduct are in remarkably close agreement with the MM2 calculated structures.     

Synthesis and characterization of difluoromethylene-homo[60]fullerene, C60(CF2)

Refluxing of the o-DCB solution of C60 with CF2ClCOONa and 18-crown-6 leads to formation of C60(CF2)n (n = 1-3); the monoadduct C60(CF2) has been found to consist of the main [6,6]- and minor [5,6]-isomers, both having an open structure.