Two-fold addition reaction of silylene to C₆₀: structural and electronic properties of a bis-adduct

• Masahiro Kako,
• Masato Kai,
• Masanori Yasui,
• Michio Yamada,
• Yutaka Maeda and
• Takeshi Akasaka

Beilstein J. Org. Chem. 2024, 20, 1179–1188, doi:10.3762/bjoc.20.100

• Figure 1 [5]. Diederich and co-workers developed a general methodology using tether-directed remote functionalization for the regioselective formation of multiple adducts of fullerenes [6]. In our earlier reports, the reactions of C60 and C70, with silylene Dip2Si (1, Dip = 2,6-diisopropylphenyl), a

• . The regioselectivity in the addition reaction of 1 with C70 was explained earlier in terms of the interaction between the HOMO of 1 and the LUMO of C70 [16]. The reaction mechanism of ethylene with a silylene substituted with thiolate ligands has been studied using theoretical calculations, in which

Synthesis and characterization of water-soluble C₆₀–peptide conjugates

• Yue Ma,
• Lorenzo Persi and
• Yoko Yamakoshi

Beilstein J. Org. Chem. 2024, 20, 777–786, doi:10.3762/bjoc.20.71

• -soluble C60 and C70 derivatives by covalently attaching biocompatible water-soluble polymers, such as polyethylene glycol (PEG) [37][38] and PVP [39]. Although these C60– and C70–polymer conjugates revealed high water-solubility, it was found that they, especially the PEG conjugates, formed micelle-like

Switchable molecular tweezers: design and applications

• Pablo Msellem,
• Maksym Dekthiarenko,
• Nihal Hadj Seyd and
• Guillaume Vives

Beilstein J. Org. Chem. 2024, 20, 504–539, doi:10.3762/bjoc.20.45

• C60 and C70 complexation, with selectivity for C70 (log KC60 = 3.3 and log KC70 = 4.7). In a follow-up of this work, they reported a similar redox-switchable biscorannulene tweezers system with a bis(arylthiol) switching unit that can be locked in the cis-conformation by forming a disulfide S–S bridge

• fullerene complexation. Other halides (Br− and F−) also allowed C60 and C70 complexation while tetrabutylammonium cations inhibited the fullerenes' complexation by competing for the cavity of the calix [72]. These calixpyrrole-based tweezers provide a good example of ON/OFF molecular sensors for neutral

Enhanced host–guest interaction between [10]cycloparaphenylene ([10]CPP) and [5]CPP by cationic charges

• Eiichi Kayahara,
• Yoshiyuki Mizuhata and
• Shigeru Yamago

Beilstein J. Org. Chem. 2024, 20, 436–444, doi:10.3762/bjoc.20.38

• + and [10]CPP is 0.365 nm, which is very close to the sum of the van der Waals radii of an sp2 carbon (0.340 nm) [44]. This mode of interaction is similar to that observed in the complex formed from [10]CPP and C70 [24]. In contrast, complex 2 has a less ordered interaction compared to 1; while each

Synthesis of π-conjugated polycyclic compounds by late-stage extrusion of chalcogen fragments

• Aissam Okba,
• Pablo Simón Marqués,
• Kyohei Matsuo,
• Naoki Aratani,
• Hiroko Yamada,
• Gwénaël Rapenne and
• Claire Kammerer

Beilstein J. Org. Chem. 2024, 20, 287–305, doi:10.3762/bjoc.20.30

• developed by Murata, Komatsu et al. [80]. In this approach, C60 or C70 fullerenes are modified stepwise towards an open-cage derivative in order to encapsulate small molecules such as H2 [81][82]. Eventually, the chemical modifications are reversed to close the hole and give an endohedral fullerene. As

• -dihydrothiophene 1-oxides [79]. SO-extrusion as a key step in the synthesis of fullerenes (C60 and C70) encapsulating H2 molecules [80][82]. Synthesis of diepoxytetracene precursor 56 and its on-surface conversion into tetracene upon O-extrusion. Inset in the top right shows a Laplace-filtered AFM image of a

Unveiling the regioselectivity of rhodium(I)-catalyzed [2 + 2 + 2] cycloaddition reactions for open-cage C₇₀ production

• Cristina Castanyer,
• Anna Pla-Quintana,
• Anna Roglans,
• Albert Artigas and
• Miquel Solà

Beilstein J. Org. Chem. 2024, 20, 272–279, doi:10.3762/bjoc.20.28

• holds significant promise for applications in the fields of medicinal chemistry, materials science, and photovoltaics. In this study, we investigate the regioselectivity of the rhodium(I)-catalyzed [2 + 2 + 2] cycloaddition reactions between diynes and C70 as a novel procedure for generating C70 bis

• (fulleroid) derivatives. The aim is to shed light on the regioselectivity of the process through both experimental and computational approaches. In addition, the photooxidation of one of the C–C double bonds in the synthesized bis(fulleroids) affords open-cage C70 derivatives having a 12-membered ring

• unexpectedly, the [6,6]-bond in C60 was the one involved in this [2 + 2 + 2] cycloaddition. Although there are several papers reporting the opening of a hole in C70 [39][40][41][42][43][44][45], this chemistry has been less explored than in C60. The lower D5h symmetry of C70 compared to the Ih of C60 increases

Decarboxylative 1,3-dipolar cycloaddition of amino acids for the synthesis of heterocyclic compounds

• Xiaofeng Zhang,
• Xiaoming Ma and
• Wei Zhang

Beilstein J. Org. Chem. 2023, 19, 1677–1693, doi:10.3762/bjoc.19.123

• (such as C60/C70 fullerenes) [56][57][58]. Other than amino esters and amino acids shown in Scheme 1, cyclic amines can also react with arylaldehydes to form B1-type semi-stabilized AMYs. In this context, the Seidel group reported the reactions of pyrrolidines 5 with arylaldehydes for the formation of

Polymer and small molecule mechanochemistry: closer than ever

• José G. Hernández

Beilstein J. Org. Chem. 2022, 18, 1225–1235, doi:10.3762/bjoc.18.128

• the covalent capsule 5 (made from resorcinarene caps connected by four dihydrazone units of ʟ-cysteine) with C60 and C70 fullerenes upon neat ball milling in a planetary ball mill (Figure 6). The mechanochemical complexation is remarkable since the porous capsule does not possess large enough openings

• . Mechanochemical solid-state complexation of organic capsule 5 with fullerenes C70 in a planetary ball mill. Figure 6 was adapted from [65], H. Jędrzejewska et al., “Porous Molecular Capsules as Non- Polymeric Transducers of Mechanical Forces to Mechanophores”, Chem. Eur. J., with permission from John Wiley and

Using multiple self-sorting for switching functions in discrete multicomponent systems

• Amit Ghosh and
• Michael Schmittel

Beilstein J. Org. Chem. 2020, 16, 2831–2853, doi:10.3762/bjoc.16.233

• chemical stimuli yielding different supramolecular products. The porphyrin ligands of the cage [Zn4(8')6]8+ interacted favorably with C70 as a guest, whereas an electron-rich aromatic crown-ether did thread onto the electron-deficient naphthalene diimides of cage [Zn4(7')6]8+ forming mechanically

• -interlocked catenanes. When both cages were mixed without C70, the dynamic combinatorial library (DCL) of seven compositionally distinct mixed-ligand Zn4L6 cages was observed (Figure 5b). An efficient self-sorting was only observed after the addition of the guest C70. As expected, the cage [Zn4(8')6]8

• + encapsulated the C70 (state SelfSORT-I), and forced the mixture to reconstitute into the 2-fold self-sorted homoleptic structures (Figure 5b). In a separate work, Nitschke and co-workers reported on a series of homoleptic supramolecular MII6L4 pseudooctahedra (Figure 6a,b) that had formed from the subcomponent

Water-soluble host–guest complexes between fullerenes and a sugar-functionalized tribenzotriquinacene assembling to microspheres

• Si-Yuan Liu,
• Xin-Rui Wang,
• Man-Ping Li,
• Wen-Rong Xu and
• Dietmar Kuck

Beilstein J. Org. Chem. 2020, 16, 2551–2561, doi:10.3762/bjoc.16.207

• Department of Chemistry, Center for Molecular Materials (CM2), Bielefeld University, 33615 Bielefeld, Germany 10.3762/bjoc.16.207 Abstract A sugar-functionalized water-soluble tribenzotriquinacene derivative bearing six glucose residues, TBTQ-(OG)6, was synthesized and its interaction with C60 and C70

• -fullerene in co-organic solvents and aqueous solution was investigated by fluorescence spectroscopy and ultraviolet-visible spectroscopy. The association stoichiometry of the complexes TBTQ-(OG)6 with C60 and TBTQ-(OG)6 with C70 was found to be 1:1 with binding constants of Ka = (1.50 ± 0.10) × 105 M−1 and

• C60 and C70 [1][2][3][4][5]. It is generally accepted that good complexation of fullerenes requires host molecules with bowl or basket-like shapes, such as calixarenes [6], corannulenes [7][8][9][10], cyclodextrins [11][12][13], cyclotriveratrylenes [14][15][16], and similar macrocycles [17][18][19

Synthetic approaches to bowl-shaped π-conjugated sumanene and its congeners

• Shakeel Alvi and
• Rashid Ali

Beilstein J. Org. Chem. 2020, 16, 2212–2259, doi:10.3762/bjoc.16.186

Synthesis of C₇₀-fragment buckybowls bearing alkoxy substituents

• Yumi Yakiyama,
• Shota Hishikawa and
• Hidehiro Sakurai

Beilstein J. Org. Chem. 2020, 16, 681–690, doi:10.3762/bjoc.16.66

• Yumi Yakiyama Shota Hishikawa Hidehiro Sakurai Division of Applied Chemistry, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan 10.3762/bjoc.16.66 Abstract Buckybowls bearing a C70 fragment having two alkoxy groups were synthesized and their structural

• equilibrium between the Pd(IV) intermediates through C–H bond activation. Keywords: buckybowl; C70; rearrangement through C–H bond activation; Introduction The study of buckybowls, the bowl-shaped π-conjugated aromatic hydrocarbons corresponding to the fragments of fullerenes, pioneered by the works on

• colannulene and sumanene, have been attracting great interests owing to their unique chemical and physical properties [1][2][3][4][5][6][7][8] and was extended to larger systems [9][10][11][12][13][14][15][16][17]. Among them, buckybowls having a C70 fragment are expected to exhibit different properties from

Selective detection of DABCO using a supramolecular interconversion as fluorescence reporter

• Indrajit Paul,
• Debabrata Samanta,
• Sudhakar Gaikwad and
• Michael Schmittel

Beilstein J. Org. Chem. 2019, 15, 1371–1378, doi:10.3762/bjoc.15.137

• porphyrin edge capsules to cone-shaped inclusion complexes depending on the presence of C60/C70, however, a process that was not selective for one of the guests [24]. A spectacular case of guest sensing, but not guest-induced recognition, was demonstrated by Clever in a supramolecular cage-to-cage

Fabrication of supramolecular cyclodextrin–fullerene nonwovens by electrospinning

• Hiroaki Yoshida,
• Ken Kikuta and
• Toshiyuki Kida

Beilstein J. Org. Chem. 2019, 15, 89–95, doi:10.3762/bjoc.15.10

• of CD–fullerene pairs to form similar 2:1 inclusion complexes are β-CD–C60 [32] and γ-CD–C70 [33]. However, such combinations are unlikely to form inclusion complexes in solution compared with that of γ-CD–C60 due to the mismatched size of CD and fullerene. The formation of both inclusion complexes

• reflectance peaks (around 255 and 330 nm). In the case of γ-CD–C70, the solution is pale dark purple with UV–vis absorption peaks (214, 235, 254, 332, 361, 378, and 474 nm) assignable to C70 [33], and electrospun fibers with a diameter of 2.0 ± 0.74 μm with UV–vis diffuse reflectance peaks (around 260, 330

• , 380, and 475 nm) are observed. These results clearly suggest the successful preparation of β-CD (γ-CD) fiber materials with molecularly dispersed C60 (C70). The preparation of hybrid materials of a polymer and a CD–fullerene inclusion complex might be interesting to enhance material integrity and

Calixazulenes: azulene-based calixarene analogues – an overview and recent supramolecular complexation studies

• Paris E. Georghiou,
• Shofiur Rahman,
• Abdullah Alodhayb,
• Hidetaka Nishimura,
• Jaehyun Lee,
• Atsushi Wakamiya and
• Lawrence T. Scott

Beilstein J. Org. Chem. 2018, 14, 2488–2494, doi:10.3762/bjoc.14.225

•  1) and on its mechanochemically-generated solid-state complex of C60-fullerene [17]. This all-hydrocarbon, wide-rim octaphenyl-functionalized calix[4]azulene was designed to evaluate its potential for encapsulating C60 or C70 fullerenes. The lack of sufficient solubility of 5 in common organic

Separation and identification of indene–C₇₀ bisadduct isomers

• Bolong Zhang,
• Jegadesan Subbiah,
• David J. Jones and
• Wallace W. H. Wong

Beilstein J. Org. Chem. 2016, 12, 903–911, doi:10.3762/bjoc.12.88

• –C70 bisadduct (IC70BA) mixture, we report the full fractionation and identification of the bisadduct species in the material. Eleven fractions of IC70BA isomers were separated by high-performance liquid chromatography. A number of fractions contained relatively pure isomer species and their

• fullerene bisadducts, specifically the C60 (IC60BA) and C70 (IC70BA) analogues (Figure 1), have been used successfully to boost the performance of poly(3-hexylthiopehene) (P3HT) based devices. The use of fullerene bisadducts improves the open circuit voltage of the device compared to mono-functionalized

• between C70 and two isoindene molecules generated in situ from indene. The symmetry of the ellipsoidal C70 molecule means that there are four different bonds between two six membered rings ([6,6]-bonds) that can participate in the Diel–Alder reaction. These are known as α-, β-, ε- and κ-bonds (Figure 2a

Supramolecular chemistry: from aromatic foldamers to solution-phase supramolecular organic frameworks

• Zhan-Ting Li

Beilstein J. Org. Chem. 2015, 11, 2057–2071, doi:10.3762/bjoc.11.222

• ]. Thus, oligomers 13–15 may be considered as structural prototypes for creating new modifiable backbones. For example, porphyrin-appended U-shaped molecular tweezers 16 and 17 have been produced (Scheme 8). Compound 16 complexed C60 or C70 or their derivatives in chloroform or toluene through porphyrin

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

• through the sulfur bridges. The Ar-S-TTF molecules are size and shape matched for fullerenes (C60/C70), and the peripheral aryls show large rotational freedom that could adjust their spatial alignment to adapt to the environmental variations [61]. Regarding the structural feature of Ar-S-TTF, we have

• performed the complexation of Ar-S-TTFs with C60/C70, and found that Ar-S-TTF could form D–A type inclusion complexes with C60/C70 [63]. Crystallographic investigation reveals that the multidimensional interaction networks consisting of a central TTF core, peripheral aryls, and fullerenes are the key

• factors to stabilize the resulting supramolecular structures. Meanwhile, the solid state absorption study indicates that the inclusion complexes display a photoexcited electronic transition between Ar–S–TTF and C60/C70. To gain further insight into the structural features of Ar-S-TTF upon complexation

Homochiral BINOL-based macrocycles with π-electron-rich, electron-withdrawing or extended spacing units as receptors for C₆₀

• Marco Caricato,
• Silvia Díez González,
• Idoia Arandia Ariño and
• Dario Pasini

Beilstein J. Org. Chem. 2014, 10, 1308–1316, doi:10.3762/bjoc.10.132

• made chiral by substituting one of the nitrogen atoms, and the enantioselective complexation of chiral higher fullerenes (C84) has been demonstrated [22]. Complexes of C60 and C70 with large, calix-type macrocycles formed by π-electron deficient pyridine aromatic rings bridged by a nitrogen heteroatom

• , have been reported and characterized in terms of thermodynamic stability by using fluorescence measurements [23]. Martin, Perez et al. have reported on a series of extended TTF units able to form strong complexes with C60 and C70 in organic solutions [24][25]. We have recently reported an efficient

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

• curvature on the convex surface (i.e., the carbon atoms with the greatest POAV angle, see Figure 5). Similar site selectivity for the 6:6-bond that incorporates the most pyramidalized carbon atoms has previously been observed in the functionalization of fullerene C70 [56]. As explained in the introductory

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

• 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

• oxalate or acetate bridged triads 4–6 were prepared using a similar strategy. To link the two C60 or two C70 fullerene cages with the oxalate spacer (compounds 4 and 6) a one-step procedure was used in which the corresponding fulleropyrrolidine was treated with an excess of oxalyl chloride in the presence

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

• complex to that observed by Raston for 3i (Figure 25). One area of interest has been the selective separation of C70 from a mixture of fullerenes. Komatsu proposed a method for the preferential precipitation of C70 over C60 with p-halooxacalix[3]arenes [80]. p-Iodooxacalix[3]arene (3j) was able to achieve

Mitomycins syntheses: a recent update

• Jean-Christophe Andrez

Beilstein J. Org. Chem. 2009, 5, No. 33, doi:10.3762/bjoc.5.33

New diarylmethanofullerene derivatives and their properties for organic thin- film solar cells

• Daisuke Sukeguchi,
• Surya Prakash Singh,
• Mamidi Ramesh Reddy,
• Hideyuki Yoshiyama,
• Rakesh A. Afre,
• Yasuhiko Hayashi,
• Hiroki Inukai,
• Tetsuo Soga,
• Shuichi Nakamura,
• Norio Shibata and
• Takeshi Toru

Beilstein J. Org. Chem. 2009, 5, No. 7, doi:10.3762/bjoc.5.7

• , thermal treatment under reflux in toluene gave diarylmethanofullerenes 1a–k in good yields. The C70 derivative 2, a mixture of isomers, was prepared from 16a by a procedure similar to those of C60 derivatives 1a–k using C70 instead of C60. As expected, all the compounds were soluble in all organic

• work as acceptors, probably because of their low solubility in ODCB. The bis(methoxycarbonyl)phenyl- and cyanophenyl-substituted methanofullerenes 1f and 1g showed good PCE, whereas nitrophenyl-substituted methanofullerenes 1h and 1i did not work as acceptors. (Methoxycarbonyl)phenylmethano-C70