Art, auto-mechanics, and supramolecular chemistry. A merging of hobbies and career

• Eric V. Anslyn

Beilstein J. Org. Chem. 2016, 12, 362–376, doi:10.3762/bjoc.12.40

• soda indeed sparked the idea of pursuing a citrate sensor, the idea of working on sensing had been percolating in my mind for a while. A. P. De Silva was pioneering the use of PET (photoinduced electron transfer) signaling [71], Seiji Shinkai (and his post-doctoral associate Tony James) were creating

Bright molecules for sensing, computing and imaging: a tale of two once-troubled cities

• A. Prasanna de Silva

Beilstein J. Org. Chem. 2015, 11, 2774–2784, doi:10.3762/bjoc.11.298

• electron transfer) sensing/switching as a design tool, b) the construction of a market-leading blood electrolyte analyzer and c) the invention of molecular logic-based computation as an experimental field, are delineated. Efforts to extend the philosophy of these approaches into issues of small object

• identification, nanometric mapping, animal visual perception and visual art are also outlined. Keywords: blood electrolyte analyzer; luminescent PET sensing/switching; molecular logic-based computation; photoinduced electron transfer; small molecular edge detection; Review Prologue Colombo, Sri Lanka: A civil

• from this ferment was photoinduced electron transfer (PET) [6][7], especially following the previous realization of its central role in green plant photosynthesis. It appealed to the physicochemical side of me that PET allows one to think primarily in terms of redox potentials, while atomic details

Recent advances in metathesis-derived polymers containing transition metals in the side chain

• Ileana Dragutan,
• Valerian Dragutan,
• Bogdan C. Simionescu,
• Albert Demonceau and
• Helmut Fischer

Beilstein J. Org. Chem. 2015, 11, 2747–2762, doi:10.3762/bjoc.11.296

• )(η6-C6Me6)][PF6] have been recently revealed as potential electron-transfer reagents provided with a high stability [45]. On extending their research to the areas of anion sensing and nanomaterials, the Astruc group accomplished an efficient synthesis, by ROMP with Grubbs 3rd generation catalyst, of

Recent developments in copper-catalyzed radical alkylations of electron-rich π-systems

• Kirk W. Shimkin and
• Donald A. Watson

Beilstein J. Org. Chem. 2015, 11, 2278–2288, doi:10.3762/bjoc.11.248

• catalyst. The resultant stabilized alkyl radical then undergoes coupling with a nitronate anion, forging the C–C bond. Single electron transfer from the resultant radical anion to the Cu(II) halide results in the observed product while simultaneously reducing the metal center to regenerate the catalyst. In

Photoinduced 1,2,3,4-tetrahydropyridine ring conversions

• Baiba Turovska,
• Henning Lund,
• Viesturs Lūsis,
• Anna Lielpētere,
• Edvards Liepiņš,
• Sergejs Beljakovs,
• Inguna Goba and
• Jānis Stradiņš

Beilstein J. Org. Chem. 2015, 11, 2166–2170, doi:10.3762/bjoc.11.234

• , Langelandsgade 140, DK 8000 Aarhus, Denmark 10.3762/bjoc.11.234 Abstract Stable heterocyclic hydroperoxide can be easily prepared as a product of fast oxidation of a 1,2,3,4-tetrahydropyridine by 3O2 if the solution is exposed to sunlight. The driving force for the photoinduced electron transfer is calculated

• ; photoinduced electron transfer; pyrrolidine; tetrahydropyridine; Introduction Increased attention has been paid to the chemistry of cyclic organic peroxides since it was found that naturally occurring representatives of this group possess biological activity, particular antimalarial [1][2]. Significantly less

• solution. The reaction of dioxygen (3O2) having a triplet ground state with tetrahydropyridine 1 having a singlet ground state is spin forbidden. On the other hand, the electron transfer from the organic compound to 3O2 resulting in the formation of a radical cation of the organic donor and the radical

C–H bond halogenation catalyzed or mediated by copper: an overview

• Wenyan Hao and
• Yunyun Liu

Beilstein J. Org. Chem. 2015, 11, 2132–2144, doi:10.3762/bjoc.11.230

• roles of both reaction medium and halogen source. Notably, attempts in the chlorination of the alkene C–H bond under identical atmosphere were not successful. In the reaction process, a single electron transfer (SET) from the aryl ring to the coordinated Cu(II) complex 3 to the Cu(I) species 4 was the

• and 2-phenyl-1,3,4-oxadiazole were smoothly iodinated to provide iodoheteroarenes 18 (Scheme 10) [45]. As typical electron-enriched arenes, phenols and analogous arenes tend to undergo a single-electron transfer process [46], the property of these arenes also resulted in sound attention to their C–H

• chlorination of 33 was not observed under the corresponding chlorination conditions, probably because the decomposition of CuCl2 into CuCl and Cl2 is much less favorable. The mechanism of the chlorination was not yet clear, but presumably the reaction was initiated by electron transfer from the arenes to the

A new approach to ferrocene derived alkenes via copper-catalyzed olefination

• Vasily M. Muzalevskiy,
• Aleksei V. Shastin,
• Alexandra D. Demidovich,
• Namiq G. Shikhaliev,
• Abel M. Magerramov,
• Victor N. Khrustalev,
• Rustem D. Rakhimov,
• Sergey Z. Vatsadze and
• Valentine G. Nenajdenko

Beilstein J. Org. Chem. 2015, 11, 2072–2078, doi:10.3762/bjoc.11.223

• intermediates in the synthesis of ferrocene analogs of tamoxifen and other medicinally relevant molecules. Electrochemical properties of halovinylferrocenes The ferrocene unit possesses several exciting electrochemical characteristics, such as fast electron-transfer rate, low oxidation potential, and stability

• was found only in the case of bis(halovinyl)ferrocenes. Our results clearly indicate that the anodic and cathodic electrochemical processes proceed on different parts of the molecules. While in the anodic region the changes are localized on the iron atom, the electron transfer from the cathode occurs

• we assume that the radical-ions formed after the first electron transfer would enter the intramolecular cyclization reaction involving the second adjacent double bond with subsequent electropolymerization. The latter is confirmed by a pronounced decrease in current values (3–4 times) as compared to

Effective ascorbate-free and photolatent click reactions in water using a photoreducible copper(II)-ethylenediamine precatalyst

• Redouane Beniazza,
• Natalia Bayo,
• Florian Molton,
• Carole Duboc,
• Stéphane Massip,
• Nathan McClenaghan,
• Dominique Lastécouères and
• Jean-Marc Vincent

Beilstein J. Org. Chem. 2015, 11, 1950–1959, doi:10.3762/bjoc.11.211

• efficient photoinduced electron transfer process leading to a fast Cu(II) to Cu(I) reduction, the final electron source being the solvent. The photoreduction process was extremely efficient, photoreduction quantum yields (Фred) ranging from 0.17 up to around 1 being measured in good H-atom donating solvents

Polythiophene and oligothiophene systems modified by TTF electroactive units for organic electronics

• Alexander L. Kanibolotsky,
• Neil J. Findlay and
• Peter J. Skabara

Beilstein J. Org. Chem. 2015, 11, 1749–1766, doi:10.3762/bjoc.11.191

• . Photoexcitation of 39 can lead to an increase in the donor ability of the TTF unit due to a greater contribution of the quinoidal structure to the excited polymer backbone, and foster electron transfer from the TTF moiety to PC61BM (Scheme 10). However, further hole transfer from the TTF unit to the PTV backbone

Preparative semiconductor photoredox catalysis: An emerging theme in organic synthesis

• David W. Manley and
• John C. Walton

Beilstein J. Org. Chem. 2015, 11, 1570–1582, doi:10.3762/bjoc.11.173

• photoredox catalysts (PRCs), have been exploited that enable visible and UVA radiation to be put to use without directly breaking chemical bonds. Typically, PRCs when photoexcited mediate electron transfer between suitable precursor substrates thus generating radical ions and thereby launching fresh

• pattern on the ligands and by changing the metal. In the case of the prototypical PRC, Ru(bpy)32+, absorption of a photon generates the long lived triplet species *Ru(bpy)32+ that can act both as a reductant and an oxidant. Electron transfer to an acceptor molecule A generates the A–• radical anion

• valence band holes [61]. Electron transfer from the carboxylate π-orbitals to a hole trap site supplies surface bound RXCH2-CO2• radicals. Rapid β-scissions of these species yield the desired free RXCH2• radicals. That these species are intermediates has been confirmed by detection of their EPR spectra in

Synthesis and spectroscopic properties of β-triazoloporphyrin–xanthone dyads

• Dileep Kumar Singh and
• Mahendra Nath

Beilstein J. Org. Chem. 2015, 11, 1434–1440, doi:10.3762/bjoc.11.155

• synthesized and evaluated for their photophysical properties. These compounds have successfully demonstrated the occurrence of an excited electron transfer from the porphyrin subunit to the attached acceptor moieties. On the other hand, some photoinduced electron transfer systems such as porphyrin

Intermolecular addition reactions of N-alkyl-N-chlorosulfonamides to unsaturated compounds

• Gerold Heuger and
• Richard Göttlich

Beilstein J. Org. Chem. 2015, 11, 1226–1234, doi:10.3762/bjoc.11.136

• an N-alkyl substituent, which we anticipated to generate readily from the corresponding N-chloroamides by electron transfer from copper(I) catalysts. Results and Discussion The N-chlorosulfonamides can be easily prepared by reaction of the sulfonamide with calcium hypochlorite and moist alumina [34

New tris- and pentakis-fused donors containing extended tetrathiafulvalenes: New positive electrode materials for rechargeable batteries

• Shintaro Iwamoto,
• Yuu Inatomi,
• Daisuke Ogi,
• Satoshi Shibayama,
• Yukiko Murakami,
• Minami Kato,
• Kazuyuki Takahashi,
• Kazuyoshi Tanaka,
• Nobuhiko Hojo and
• Yohji Misaki

Beilstein J. Org. Chem. 2015, 11, 1136–1147, doi:10.3762/bjoc.11.128

• waves of 9d correspond to one-electron transfer process, while the others correspond to two-electron transfer processes. The redox potentials of 5d, 7d and 9d are summarized in Table 2 together with their related compounds. The first two-electron redox potentials of 5d (Em1 = −0.01 V) and 7d (Em1

• = −0.04 V) were more negative by 0.13 and 0.16 V than the first redox potential of a TTPY derivative 2e (E1 = +0.12 V) measured under the identical conditions. The first redox waves of 5d and 7d involved two-electron transfer processes, and that E1 of the extended donors 3c and 18 (−0.06 V) was lower than

• repulsion in 7d6+. As for 9d, two positive charges in 9d2+ are probably distributed mainly on each of the two thiophene-inserted TTF moieties, since the first redox wave of 9d corresponds to a simultaneous two-electron transfer process, and the Em1 (−0.07 V) is comparable to the E1 of 18 (−0.06 V) as shown

A hybrid electron donor comprising cyclopentadithiophene and dithiafulvenyl for dye-sensitized solar cells

• Gleb Sorohhov,
• Chenyi Yi,
• Michael Grätzel,
• Silvio Decurtins and
• Shi-Xia Liu

Beilstein J. Org. Chem. 2015, 11, 1052–1059, doi:10.3762/bjoc.11.118

• substantial charge recombination losses during the electron-injection process, very probably caused by self-aggregation on the TiO2 surface and fast back-electron transfer upon photoexcitation. Conclusion In summary, we have synthesized two new organic photosensitizers featured with a DTF–CPDT hybrid as an

Chiroptical properties of 1,3-diphenylallene-anchored tetrathiafulvalene and its polymer synthesis

• Masashi Hasegawa,
• Junta Endo,
• Seiya Iwata,
• Toshiaki Shimasaki and
• Yasuhiro Mazaki

Beilstein J. Org. Chem. 2015, 11, 972–979, doi:10.3762/bjoc.11.109

• voltammetry (CV) analyses (Figure 4 and Table 1). In CVs, there are two sets of reversible redox waves in the conventional potential range. Compound 3 exhibits two two-electron transfer waves at E11/2 = −0.01 V and E21/2 = 0.31 V, whereas PTDPA exhibits in a similar manner at E11/2 = 0.03 V and E21/2 = 0.30 V

Synthesis and characterization of the cyanobenzene-ethylenedithio-TTF donor

• Sandrina Oliveira,
• Dulce Belo,
• Isabel C. Santos,
• Sandra Rabaça and
• Manuel Almeida

Beilstein J. Org. Chem. 2015, 11, 951–956, doi:10.3762/bjoc.11.106

• reduces the donor properties, shifting the redox potentials to higher values due to the electron withdrawing effect of the cyano groups possibly with a partial electron transfer from the donor to the acceptor moiety. This tendency is also in agreement with the redox potentials of other cyanobenzene and

Interactions between tetrathiafulvalene units in dimeric structures – the influence of cyclic cores

• Huixin Jiang,
• Virginia Mazzanti,
• Christian R. Parker,
• Søren Lindbæk Broman,
• Jens Heide Wallberg,
• Karol Lušpai,
• Adam Brincko,
• Henrik G. Kjaergaard,
• Anders Kadziola,
• Peter Rapta,
• Ole Hammerich and
• Mogens Brøndsted Nielsen

Beilstein J. Org. Chem. 2015, 11, 930–948, doi:10.3762/bjoc.11.104

• the neighbouring voltammetric peaks for the first and the second electron transfer as well as for the third and the fourth electron transfer indicates a weak (but still certain) interaction between the two TTF units in the investigated TTF dimers. During the in situ oxidation of 1b, 2b, 4, 5, 6, and 8

• polaronic species in the dimer we can observe a slight shift of the optical transition characteristic of TTF radical cation going from the first to the second electron transfer as shown in Figure 10. The strongest shifts were observed for dimers 4 and 5 while no shift was found for dimer 1b. These

• reaches two maxima in both the forward and back scans. The minimum of EPR intensity was monitored at the second electron transfer as well as at the fourth electron transfer as illustrated for compound 4 in Figure 9c. The increase of the absorbance at dominating band around 790 nm found at the foot of the

Photocatalytic nucleophilic addition of alcohols to styrenes in Markovnikov and anti-Markovnikov orientation

• Martin Weiser,
• Sergej Hermann,
• Alexander Penner and
• Hans-Achim Wagenknecht

Beilstein J. Org. Chem. 2015, 11, 568–575, doi:10.3762/bjoc.11.62

• additive. Photocatalytic additions of a variety of alcohols gave the corresponding products in good to excellent yields. The proposed photocatalytic electron transfer mechanism was supported by detection of the PDI radical anion as key intermediate and by comparison of two intramolecular reactions with

• different electron density. Representative mesoflow reactor experiments allowed to significantly shorten the irradiation times and to use sunlight as “green” light source. Keywords: electron transfer; perylene bisimide; photocatalysis; photochemistry; pyrene; Introduction Photocatalysts are organic or

• , Maroulis et al. [17][18]. They demonstrated that electron-rich naphthalenes are able to photoinitiate methanol additions to olefins into the Markovnikov orientation and proposed an oxidative electron transfer mechanism for this process [17]. Complementarily, electron-poor naphthalenes yielded the anti

Metal-free one-pot synthesis of 2-substituted and 2,3-disubstituted morpholines from aziridines

• Hongnan Sun,
• Binbin Huang,
• Run Lin,
• Chao Yang and
• Wujiong Xia

Beilstein J. Org. Chem. 2015, 11, 524–529, doi:10.3762/bjoc.11.59

• mechanism was proposed as shown in Scheme 4. Initially, aziridine 1a might participate in single-electron transfer (SET) with the persulfate anion to render the radical cation A [32][34]. Concerted ring opening and nucleophilic addition leads to amino radical intermediate B, which is converted to the

Eosin Y-catalyzed visible-light-mediated aerobic oxidative cyclization of N,N-dimethylanilines with maleimides

• Zhongwei Liang,
• Song Xu,
• Wenyan Tian and
• Ronghua Zhang

Beilstein J. Org. Chem. 2015, 11, 425–430, doi:10.3762/bjoc.11.48

• undergo an oxidative or reductive quenching cycle [48][49][50]. In this mechanism, a single electron transfer (SET) from 1 to 3EY* generates the amine radical cation 4, and at the same time, 3EY* is reduced to the EY•−. In the presence of oxygen, the photoredox catalytic cycle of EY is finished via a SET

• oxidation, with the production of a superoxide radical anion O2•−. Deprotonation of 4 generates α-aminoalkyl radical 5. Then 5 reacts with 2 to generate radical 6, and the latter then undergoes cyclization to form intermediate 7. Proton and electron transfer from 7 to O2•− yields the final product 3 and HOO

Electrochemical oxidation of cholesterol

• Jacek W. Morzycki and
• Andrzej Sobkowiak

Beilstein J. Org. Chem. 2015, 11, 392–402, doi:10.3762/bjoc.11.45

• ratio of 10:3 (Scheme 7). However, several byproducts were also formed. Voltammetric measurements indicated that the cholesterol oxidation process is controlled by the rate of the electron transfer. It was proven that the oxidation occurs at the allylic position. The C7 carbocation is formed by a two

• -electron transfer and then a nucleophile (acetate) is added to this intermediate, preferentially from the less sterically hindered α-side. An interesting product of the electrochemical oxidation of cholesterol [39], i.e. dicholesteryl ether 18, was obtained in 28% yield during the electrolysis carried out

• diffusion to the anode can be attributed to the formation of N-acetylcholesterylamine (19). All observed products can be formed through a common intermediate. It seems that the first step of the reaction is a one-electron transfer from the oxygen atom of cholesterol to the anode (Scheme 9). The heterolytic

Functionalized branched EDOT-terthiophene copolymer films by electropolymerization and post-polymerization “click”-reactions

• Miriam Goll,
• Adrian Ruff,
• Erna Muks,
• Felix Goerigk,
• Beatrice Omiecienski,
• Ines Ruff,
• Rafael C. González-Cano,
• Juan T. Lopez Navarrete,
• M. Carmen Ruiz Delgado and
• Sabine Ludwigs

Beilstein J. Org. Chem. 2015, 11, 335–347, doi:10.3762/bjoc.11.39

• -rich copolymers (1:3, 1:5 and 1:10), while PEDOT-N3 and the PEDOT-N3-rich 1:1 copolymers show a chemically irreversible electron transfer reaction under our conditions. These data are consistent with those obtained for P(EDOT-co-3T) films. The in situ spectroelectrochemistry data in Figure 4B–E reveals

Stereoselective cathodic synthesis of 8-substituted (1R,3R,4S)-menthylamines

• Carolin Edinger,
• Jörn Kulisch and
• Siegfried R. Waldvogel

Beilstein J. Org. Chem. 2015, 11, 294–301, doi:10.3762/bjoc.11.34

• the electron transfer rate due to steric shielding of the oxime functionality (see Scheme 7). Also the low solubility of the substrate is obstructive. Diastereomerically pure 8-substituted menthylamines To obtain diastereomerically and analytically pure 8-substituted (1R,3R,4S)-menthylamines, each

Photovoltaic-driven organic electrosynthesis and efforts toward more sustainable oxidation reactions

• Bichlien H. Nguyen,
• Robert J. Perkins,
• Jake A. Smith and
• Kevin D. Moeller

Beilstein J. Org. Chem. 2015, 11, 280–287, doi:10.3762/bjoc.11.32

• substrate at the anode decreases to the point that the rate of substrate oxidation is small relative to the rate of electron transfer. At that point, the potential at the anode begins to increase and the selectivity of the reaction for the initial substrate is lost. When a low current density is used for

• counter ions for the ions generated at the electrodes and serves to reduce the resistance of the cell by making the electron-transfer reaction at the electrodes easier. The presence of this electrolyte, often used in large excess, can render an electrochemical reaction less than sustainable unless the

• efforts began by examining reactions where the substrate to be oxidized underwent the electron-transfer reaction directly at the electrode surface. We have employed reactions of this nature to functionalize amides [13][14] and to conduct umpolung reactions [15][16] that originate from electron-rich

Cross-dehydrogenative coupling for the intermolecular C–O bond formation

• Igor B. Krylov,
• Vera A. Vil’ and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2015, 11, 92–146, doi:10.3762/bjoc.11.13