Selected synthetic strategies to cyclophanes

• Sambasivarao Kotha,
• Mukesh E. Shirbhate and
• Gopalkrushna T. Waghule

Beilstein J. Org. Chem. 2015, 11, 1274–1331, doi:10.3762/bjoc.11.142

• cyclized product. The cleavage of the acetate groups with sodium methoxide in methanol gave the glycophane (a glycophane is a hybrid of carbohydrate and cyclophane) 143 (27%, Scheme 21). The synthesis of fullerene-related molecules with high binding affinity and/or high selectivity is an active research

Donor–acceptor type co-crystals of arylthio-substituted tetrathiafulvalenes and fullerenes

• Xiaofeng Lu,
• Jibin Sun,
• Shangxi Zhang,
• Longfei Ma,
• Lei Liu,
• Hui Qi,
• Yongliang Shao and
• Xiangfeng Shao

Beilstein J. Org. Chem. 2015, 11, 1043–1051, doi:10.3762/bjoc.11.117

• co-crystals of fullerene (as the acceptor) and arylthio-substituted tetrathiafulvalene derivatives (Ar-S-TTF, as the donor) were prepared and their structural features were thoroughly investigated. The formation of co-crystals relies on the flexibility of Ar-S-TTF and the size matches between Ar-S

• -TTF and fullerene. Regarding their compositions, the studied co-crystals can be divided into two types, where types I and II have donor:acceptor ratios of 1:1 and 1:2, respectively. Multiple intermolecular interactions are observed between the donor and acceptor, which act to stabilize the structures

• of the resulting co-crystals. In the type I co-crystals, the fullerene molecule is surrounded by four Ar-S-TTF molecules, that is, two Ar-S-TTF molecules form a sandwich structure with one fullerene molecule and the other two Ar-S-TTF molecules interact with the fullerene molecule along their lateral

Mechanical stability of bivalent transition metal complexes analyzed by single-molecule force spectroscopy

• Manuel Gensler,
• Christian Eidamshaus,
• Maurice Taszarek,
• Hans-Ulrich Reissig and
• Jürgen P. Rabe

Beilstein J. Org. Chem. 2015, 11, 817–827, doi:10.3762/bjoc.11.91

• and possible hydrophobic interactions was published in 2009 by Zhang et al. [37]. They compared the monovalent interaction of a porphyrin ligand to a C60 fullerene with the bivalent interaction of two ligands to one C60 (pincer complex) in aqueous environment. Thereby the rupture length decreased from

Synthesis of uniform cyclodextrin thioethers to transport hydrophobic drugs

• Lisa F. Becker,
• Dennis H. Schwarz and
• Gerhard Wenz

Beilstein J. Org. Chem. 2014, 10, 2920–2927, doi:10.3762/bjoc.10.310

• affinity towards rocuronium [24][25]. Furthermore, hydrophilic γ-CD thioethers show high affinities to other guests such as polycyclic aromatic hydrocarbons [26], botulin [27][28], and fullerene C60 [29]. Hydrophilic β-CD thioethers also tightly complex volatile benzene derivatives leading to a significant

Solution processable diketopyrrolopyrrole (DPP) cored small molecules with BODIPY end groups as novel donors for organic solar cells

• Diego Cortizo-Lacalle,
• Calvyn T. Howells,
• Upendra K. Pandey,
• Joseph Cameron,
• Neil J. Findlay,
• Anto Regis Inigo,
• Tell Tuttle,
• Peter J. Skabara and
• Ifor D. W. Samuel

Beilstein J. Org. Chem. 2014, 10, 2683–2695, doi:10.3762/bjoc.10.283

• the triads, theoretical DFT and TDDFT calculations were performed. Keywords: BODIPY; diketopyrrolopyrrole; organic semiconductors; organic solar cells; thiophene; Introduction The discovery of photoinduced electron transfer from conjugated polymers to fullerene (C60), and the favourable

• interpenetrating network they form within a bulk heterojunction (BHJ), has led to intense research directed towards the synthesis of conjugated polymers for bulk heterojunction organic photovoltaics (OPVs) [1][2][3]. In these devices, the conjugated polymer acts as an electron donor and a soluble fullerene, most

• results [26][27][28]. A PCE greater than 4% was achieved in combination with phenyl-C71-butyric acid methyl ester (PC71BM) [29]. Interestingly, a small molecule based on a DPP core substituted with electron-withdrawing units was also used as an acceptor in OPVs as a substitute for fullerene with PCEs of 1

Chiral phosphines in nucleophilic organocatalysis

• Yumei Xiao,
• Zhanhu Sun,
• Hongchao Guo and
• Ohyun Kwon

Beilstein J. Org. Chem. 2014, 10, 2089–2121, doi:10.3762/bjoc.10.218

• 79–94% ee (Scheme 7) [40]. Very interestingly, when using the chiral phosphine (S,S)-f-binaphane B6 as the catalyst, [60]fullerene also reacted with allenoates at room temperature, providing a wide range of optically pure (S)-cyclopenteno[60]fullerenes in up to 99% ee (Scheme 8) [41]. This study

Bis(β-lactosyl)-[60]fullerene as novel class of glycolipids useful for the detection and the decontamination of biological toxins of the Ricinus communis family

• Hirofumi Dohi,
• Takeru Kanazawa,
• Akihiro Saito,
• Keita Sato,
• Hirotaka Uzawa,
• Yasuo Seto and
• Yoshihiro Nishida

Beilstein J. Org. Chem. 2014, 10, 1504–1512, doi:10.3762/bjoc.10.155

• , Tsukuba, 305-8565, Japan 10.3762/bjoc.10.155 Abstract Glycosyl-[60]fullerenes were first used as decontaminants against ricin, a lactose recognition proteotoxin in the Ricinus communis family. A fullerene glycoconjugate carrying two lactose units was synthesized by a [3 + 2] cycloaddition reaction

• quantified by means of sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), and the results were discussed in terms of detection and decontamination of the deadly biological toxin in the Ricinus communis family. Keywords: fullerene; multivalent glycosystems; oligosaccharides; proteotoxins

• notable biological and physical properties. For example, bis(α-D-mannopyranosyl)-[60]fullerene is capable of forming a liposome-like supramolecule in aqueous media and exhibits a strong binding activity to an α-mannose-binding lectin (concanavalin A, Con A) as the result not only of carbohydrate cluster

Novel indolin-2-one-substituted methanofullerenes bearing long n-alkyl chains: synthesis and application in bulk-heterojunction solar cells

• Irina P. Romanova,
• Andrei V. Bogdanov,
• Inessa A. Izdelieva,
• Vasily A. Trukhanov,
• Gulnara R. Shaikhutdinova,
• Dmitry G. Yakhvarov,
• Shamil K. Latypov,
• Vladimir F. Mironov,
• Vladimir A. Dyakov,
• Ilya V. Golovnin,
• Dmitry Yu. Paraschuk and
• Oleg G. Sinyashin

Beilstein J. Org. Chem. 2014, 10, 1121–1128, doi:10.3762/bjoc.10.111

• 119991, Russian Federation 10.3762/bjoc.10.111 Abstract An easy, high-yield and atom-economic procedure of a C60 fullerene modification using a reaction of fullerene C60 with N-alkylisatins in the presence of tris(diethylamino)phosphine to form novel long-chain alkylindolinone-substituted

• of low-cost and flexible solar cells [1][2][3]. Organic solar cells are mainly based on bulk heterojunctions composed of a polymer donor and a fullerene acceptor. A number of promising donor materials has been developed, whereas very few successful fullerene derivatives have been proposed. The most

• popular fullerene derivative in organic photovotaics is (PCBM) [4][5][6]. As an alternative to PCBM, we recently suggested indolinone-substituted methanofullerenes (IM) [7]. The principal advantages of IM are their easier synthesis and purification as compared to PCBM [7][8]. Indeed, the IM can be

The Ugi four-component reaction as a concise modular synthetic tool for photo-induced electron transfer donor-anthraquinone dyads

• Sarah Bay,
• Gamall Makhloufi,
• Christoph Janiak and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2014, 10, 1006–1016, doi:10.3762/bjoc.10.100

• moieties C60 fullerene [43][44][45], and quinones, such as 9,10-anthraquinone as a potential two electron acceptor, have been commonly used in Do–Acc arrangements [46][47][48][49][50][51]. In previous studies phenothiazine–anthraquinone couples have been introduced into peptide scaffolds [52][53][54] and

Site-selective covalent functionalization at interior carbon atoms and on the rim of circumtrindene, a C₃₆H₁₂ open geodesic polyarene

• Hee Yeon Cho,
• Ronald B. M. Ansems and
• Lawrence T. Scott

Beilstein J. Org. Chem. 2014, 10, 956–968, doi:10.3762/bjoc.10.94

• Hee Yeon Cho Ronald B. M. Ansems Lawrence T. Scott Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467-3860, USA 10.3762/bjoc.10.94 Abstract Circumtrindene (6, C36H12), one of the largest open geodesic polyarenes ever reported, exhibits fullerene

• -like reactivity at its interior carbon atoms, whereas its edge carbons react like those of planar polycyclic aromatic hydrocarbons (PAHs). The Bingel–Hirsch and Prato reactions – two traditional methods for fullerene functionalization – afford derivatives of circumtrindene with one of the interior 6:6

• lowering of the energy of the LUMO, while leaving the energy or the HOMO relatively unchanged. Considerable effort by a number of research groups has been devoted to the preparation of fullerene fragments and to studies of their chemical and physical properties [6][7][8][9]. Several laboratories, including

Unusual polymorphism in new bent-shaped liquid crystals based on biphenyl as a central molecular core

• Anna Kovářová,
• Svatopluk Světlík,
• Václav Kozmík,
• Jiří Svoboda,
• Vladimíra Novotná,
• Damian Pociecha,
• Ewa Gorecka and
• Natalia Podoliak

Beilstein J. Org. Chem. 2014, 10, 794–807, doi:10.3762/bjoc.10.75

• ], semifluorinated alkyl chains [14][20], and fullerene [21] into the terminal chain(s), variation of the linkage groups [10][22][23][24] (ester, azo, azoxy, imine, H-bond, cinnamoyl). Also dimeric, dendritic, and polymeric liquid crystals possessing the biphenyl moiety in the centre of the bent mesogenic unit were

Thermodynamically stable [4 + 2] cycloadducts of lanthanum-encapsulated endohedral metallofullerenes

• Yuta Takano,
• Yuki Nagashima,
• M. Ángeles Herranz,
• Nazario Martín and
• Takeshi Akasaka

Beilstein J. Org. Chem. 2014, 10, 714–721, doi:10.3762/bjoc.10.65

• ]. The encapsulation results in the electron transfer from metal atoms to the fullerene cage, which leads to unique electronic, magnetic, and chemical properties for EMFs that cannot be expected for empty fullerenes. Due to the numerous electronic properties EMFs are anticipated as promising materials in

• various fields such as chemistry, biology, and material science. Among various kinds of EMFs, those encapsulating La atoms are especially attractive molecules because of their electronic and magnetic characteristics. As a result of the three electron transfer per La atom to the fullerene cage, the

• fullerenes simultaneously possess a low ionizing potential and a high electron affinity [1][2]. For mono-La endohedral fullerenes such as La@C82, the electron transfer results in paramagnetism of the fullerene cage [5]. The di-La endohedral fullerenes such as La2@C80 show diamagnetism [6]. This feature leads

Tuning the interactions between electron spins in fullerene-based triad systems

• Maria A. Lebedeva,
• Thomas W. Chamberlain,
• E. Stephen Davies,
• Bradley E. Thomas,
• Martin Schröder and
• Andrei N. Khlobystov

Beilstein J. Org. Chem. 2014, 10, 332–343, doi:10.3762/bjoc.10.31

• 10.3762/bjoc.10.31 Abstract A series of six fullerene–linker–fullerene triads have been prepared by the stepwise addition of the fullerene cages to bridging moieties thus allowing the systematic variation of fullerene cage (C60 or C70) and linker (oxalate, acetate or terephthalate) and enabling precise

• control over the inter-fullerene separation. The fullerene triads exhibit good solubility in common organic solvents, have linear geometries and are diastereomerically pure. Cyclic voltammetric measurements demonstrate the excellent electron accepting capacity of all triads, with up to 6 electrons taken

• up per molecule in the potential range between −2.3 and 0.2 V (vs Fc+/Fc). No significant electronic interactions between fullerene cages are observed in the ground state indicating that the individual properties of each C60 or C70 cage are retained within the triads. The electron–electron

Controlled synthesis of poly(3-hexylthiophene) in continuous flow

• Helga Seyler,
• Jegadesan Subbiah,
• David J. Jones,
• Andrew B. Holmes and
• Wallace W. H. Wong

Beilstein J. Org. Chem. 2013, 9, 1492–1500, doi:10.3762/bjoc.9.170

• mixing of reagents, boosting reaction rates, and safe handling of reactive intermediates. Using a commercial continuous-flow tube reactor [19], we have already demonstrated multigram synthesis of fullerene derivatives by cycloaddition reactions [11] as well as rapid conjugated-polymer synthesis using

A study on electrospray mass spectrometry of fullerenol C₆₀(OH)₂₄

• Mihaela Silion,
• Andrei Dascalu,
• Mariana Pinteala,
• Bogdan C. Simionescu and
• Cezar Ungurenasu

Beilstein J. Org. Chem. 2013, 9, 1285–1295, doi:10.3762/bjoc.9.145

• anions formed by electron addition to a fullerenyl radical shall be described as fullerene carbanions and referred to as fullerenide anions (M3 in Scheme 1) and [mM + ne]m–n∙ shall be described as molecular anions. As regards to the observation of distonic fullerenyl-fullerenate M7 ions, such distonic

• on pristine fullerene anion radicals [34][35][36][37] unquestionably confirmed their generation by electron transfer from various electron donors (aliphatic and aromatic amines especially) [38][39], one can postulate that, under ESI conditions, a distonic radical carbanion [(C60(OH)24−•)2]2−• is

• first generated by electron transfer from H2N− produced by ammonia ionization and then undergoes consecutive OH radical losses and electron redistribution until the entire reconstruction of the electronic structure of pristine fullerene is achieved. Positive-ionization-mode mass spectra In Figure 3 are

Incorporation of perfluorohexyl-functionalised thiophenes into oligofluorene-truxenes: synthesis and physical properties

• Neil Thomson,
• Alexander L. Kanibolotsky,
• Joseph Cameron,
• Tell Tuttle,
• Neil J. Findlay and
• Peter J. Skabara

Beilstein J. Org. Chem. 2013, 9, 1243–1251, doi:10.3762/bjoc.9.141

• such as fullerene fragments [4] and liquid-crystalline compounds [5]. Positions C5, C10 and C15 can be functionalised with a range of substituents, commonly saturated alkyl chains, which can enhance the solubility and processability as well as reduce intermolecular π–π stacking [6], but there are also

Enhancement of efficiency in organic photovoltaic devices containing self-complementary hydrogen-bonding domains

• Rohan J. Kumar,
• Jegadesan Subbiah and
• Andrew B. Holmes

Beilstein J. Org. Chem. 2013, 9, 1102–1110, doi:10.3762/bjoc.9.122

• -processing, leading to cost and energy input advantages in device manufacture. Recently, a donor–acceptor small molecule with a cyanopyridone moiety as the acceptor motif and displaying moderate photovoltaic efficiency in a BHJ device with a fullerene was reported [20]. The efficiency of these optimized

• reported for compound 1 [20] and are suitable for charge transfer to take place to fullerene-based electron acceptors, such as PC61BM. The NH cyanopyridone unit can presumably exist as a number of tautomers; however, if present, these do not appear to affect the electronic properties in solution

Flow photochemistry: Old light through new windows

• Jonathan P. Knowles,
• Luke D. Elliott and
• Kevin I. Booker-Milburn

Beilstein J. Org. Chem. 2012, 8, 2025–2052, doi:10.3762/bjoc.8.229

• degradations, dual-channel reactors have been used for synthetically useful transformations. Returning to the oxidation of α-terpinene, moderate yields of ascaridole were obtained by using a silica-supported fullerene promoter [38]. Similarly, L-methionine was efficiently oxidised to the corresponding

The chemistry of bisallenes

• Henning Hopf and
• Georgios Markopoulos

Beilstein J. Org. Chem. 2012, 8, 1936–1998, doi:10.3762/bjoc.8.225

• . Derivative 150 can be desilylated to a C60H36 hydrocarbon, whose C36 backbone represents ca. 60% of the fullerene framework and which can be mapped onto C60 [121]. A pericyclic reaction of conjugated bisallenes which has also been studied extensively over the years involves the Diels–Alder addition with both

Molecular solubilization of fullerene C₆₀ in water by γ-cyclodextrin thioethers

• Hai Ming Wang and
• Gerhard Wenz

Beilstein J. Org. Chem. 2012, 8, 1644–1651, doi:10.3762/bjoc.8.188

• much lower aggregation tendency than the corresponding ones of native γ-CD. Molecular solubilization of fullerene C60 in water, reaching concentrations as high as 15 μM, was achieved in the presence of 6.0 mM of a γ-CD thioether. The resulting aqueous molecular solutions of C60 free of toxic organic

• solvents will hopefully find interesting applications in biomedicine, such as in photodynamic therapy or HIV-protease inhibition. Experimental General Unless otherwise stated, all chemicals were used as received. Powdered fullerene C60 (> 99%) was purchased from Sigma Aldrich. Teflon syringe filters from

Control over molecular motion using the cis–trans photoisomerization of the azo group

• Estíbaliz Merino and
• María Ribagorda

Beilstein J. Org. Chem. 2012, 8, 1071–1090, doi:10.3762/bjoc.8.119

• : A central azobenzene, a rigid frame composed of oligo(phenylacetylenes), which in turn are anchored to azobenzene through para positions, and wheels based on fullerene C60 (azo-14) or p-carboranes (azo-15). Photoisomerization studies suggest that only the azobenzene system with p-carborane wheels

• (azo-15) may be useful as a molecular switch, because the photoisomerization of azo-fullerene 14 leads to only 8% of the cis-isomer. Although, the quantum yield obtained for cis-14 is not very high, this proportion is significant, given the speed with which energy transfer to the fullerene unit occurs

Low-generation dendrimers with a calixarene core and based on a chiral C₂-symmetric pyrrolidine as iminosugar mimics

• Marco Marradi,
• Stefano Cicchi,
• Francesco Sansone,
• Alessandro Casnati and
• Andrea Goti

Beilstein J. Org. Chem. 2012, 8, 951–957, doi:10.3762/bjoc.8.107

• interactions [10], the effect of iminosugar-based multivalent inhibitors on enzyme activity is difficult to rationalise. However, the introduction of several copies of an N-alkyl analogue of iminosugar 1-deoxynojirimycin onto a fullerene ball [8] or onto β-cyclodextrin [9] afforded the first pieces of evidence

Synthesis and mesomorphic properties of calamitic malonates and cyanoacetates tethered to 4-cyanobiphenyls

• Katharina C. Kress,
• Martin Kaller,
• Kirill V. Axenov,
• Stefan Tussetschläger and
• Sabine Laschat

Beilstein J. Org. Chem. 2012, 8, 371–378, doi:10.3762/bjoc.8.40

• malonates has been devoted to C60 fullerene dendrimers [27][28][29][30][31]. Only a few liquid crystalline cyanoacetates have been described so far. The first example, a dihydrazide, was reported by Schubert [32]. Furthermore some calamitic and bent-core mesogens derived from α-cyanocinnamic acid were

Fifty years of oxacalix[3]arenes: A review

• Kevin Cottet,
• Paula M. Marcos and
• Peter J. Cragg

Beilstein J. Org. Chem. 2012, 8, 201–226, doi:10.3762/bjoc.8.22

• species. Applications in fields as diverse as ion selective electrode modifiers, fluorescence sensors, fullerene separations and biomimetic chemistry are described. Keywords: calixarenes; host–guest chemistry; macrocycles; oxacalixarenes; Introduction Calixarenes, macrocycles which are widely used in

• subtle spectroscopic features and computer models appeared to indicate fullerene binding, structural evidence was to be more compelling. In 1998, Fuji reported the solid-state structure of 3f with C60 as proof of 1:1 binding [76]. Alignment of the oxacalix[3]arene C3 axis with the same symmetry axis of

• to a combination of several factors, of which host–C60 complex formation is only one [77]. Consequently, reported Kassoc values determined by this method should be treated with some caution. Fullerene derivatives that lack some of the symmetry of the parent compound have been shown to bind to

Imidazole as a parent π-conjugated backbone in charge-transfer chromophores

• Jiří Kulhánek and
• Filip Bureš

Beilstein J. Org. Chem. 2012, 8, 25–49, doi:10.3762/bjoc.8.4

• effort resulted in organic photovoltaic devices with a very high fill factor FF = 57% and an external quantum efficiency IPCE (incident photons converted to electrons) = 27%. These values rival those measured for popular fullerene acceptors. Imidazole chromophores incorporated into the polymer Recently