Synthesis of SF₅-containing benzisoxazoles, quinolines, and quinazolines by the Davis reaction of nitro-(pentafluorosulfanyl)benzenes

• Petr Beier and
• Tereza Pastýříková

Beilstein J. Org. Chem. 2013, 9, 411–416, doi:10.3762/bjoc.9.43

• arylacetonitriles to provide the SF5-containing benzisoxazoles. Good yields were obtained with arylacetonitriles containing the electron-neutral or electron-donor group, while those with the electron-acceptor group were found to be unreactive. Reductions of the benzisoxazoles gave ortho-aminobenzophenones in high

• various applications due to an unusual combination of the properties of the SF5 group, such as high lipophilicity, with strong electron-acceptor character. One important property of the SF5 group is its high thermal and chemical stability [14][15][16][17]. The main reason that prevents further development

• improvement of the yield was observed by increasing the amount of 6b or using a longer reaction time). Reactions with the meta-nitro-(pentafluorosulfanyl)benzene (4) proceeded well with electron-neutral- or electron-donor-substituted phenylacetonitriles. With electron-acceptor-substituted phenylacetonitriles

Highly selective synthesis of (E)-alkenyl-(pentafluorosulfanyl)benzenes through Horner–Wadsworth–Emmons reaction

• George Iakobson and
• Petr Beier

Beilstein J. Org. Chem. 2012, 8, 1185–1190, doi:10.3762/bjoc.8.131

• various aldehydes with phosphonate 3 was explored (Table 2). Aromatic aldehydes with electron-donating groups required longer reaction times than those with electron-acceptor groups. All tested aromatic aldehydes provided compounds 5 in high isolated yields and selectivities. Application of (E

Thiophene-based donor–acceptor co-oligomers by copper-catalyzed 1,3-dipolar cycloaddition

• Stefanie Potratz,
• Amaresh Mishra and
• Peter Bäuerle

Beilstein J. Org. Chem. 2012, 8, 683–692, doi:10.3762/bjoc.8.76

• electronic communication between the chromophores [21][22][23][31]. It has also been shown that a 1,2,3-triazole can act as a strong σ-electron donor [26] or as a weak π-electron acceptor [15]. In this study, we aimed at the combination of electron-rich (oligo)thiophenes as donors and electron-deficient

Enaminones in a multicomponent synthesis of 4-aryldihydropyridines for potential applications in photoinduced intramolecular electron-transfer systems

• Nouria A. Al-Awadi,
• Maher R. Ibrahim,
• Mohamed H. Elnagdi,
• Elizabeth John and
• Yehia A. Ibrahim

Beilstein J. Org. Chem. 2012, 8, 441–447, doi:10.3762/bjoc.8.50

• to the border of the visible region. In the presence of an appropriate electron-acceptor substituent in position 4, the absorbed UV irradiation can cause intramolecular electron transfer, thus converting light into charge separation over a distance of ca. 6 Å. This expectation is based on the recent

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

• °C/93.2 °C for the series of 13a/13b, respectively (Table 1). The cyano group is a stronger electron-acceptor than the ester function, and thus the cyanoacetic ester molecules are more polarized than the corresponding malonates. Stronger dipole–dipole interactions for cyano esters 13 led to an

Computational evidence for intramolecular hydrogen bonding and nonbonding X···O interactions in 2'-haloflavonols

• Tânia A. O. Fonseca,
• Matheus P. Freitas,
• Rodrigo A. Cormanich,
• Teodorico C. Ramalho,
• Cláudio F. Tormena and
• Roberto Rittner

Beilstein J. Org. Chem. 2012, 8, 112–117, doi:10.3762/bjoc.8.12

• and a nonbonding F…O interaction. The formation of the nonbonding F…O interaction in conformer A, having fluorine as electron acceptor, is supposed to be due to the partial negative atomic charge on the ether oxygen and a less negative atomic charge on the fluorine atom (the QTAIM atomic charges are

• electron acceptor (QTAIM atomic charge of −0.620 for F against −1.093 for the hydroxy oxygen), which is not so uncommon, as stated in classical textbooks on aromatic electrophilic substitution, since a resonant structure with a C=F+ contribution can take place [31]; this is shown by NBO calculations, which

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

• –57 behaves as an electron acceptor and, when substituted with electron donors at C2, an efficient ICT can be achieved. Consequently, the measured hyperpolarizabilities β increase with the rise in donating ability of the appended donors or extension of the π-conjugated path. Thiophene, used as a part

• moiety may behave as an electron acceptor or donor. Taking our series of structurally similar chromophores 21–26 and 88–93 as an example, which primarily differ in the orientation of the substituents along the imidazole ring, C4/C5 donor-substituted imidazole derivatives showed higher nonlinearities

Photoinduced electron-transfer chemistry of the bielectrophoric N-phthaloyl derivatives of the amino acids tyrosine, histidine and tryptophan

• Axel G. Griesbeck,
• Jörg Neudörfl and
• Alan de Kiff

Beilstein J. Org. Chem. 2011, 7, 518–524, doi:10.3762/bjoc.7.60

• -CH transfer can undergo several subsequent reactions, among which are secondary H transfer, cyclization, or fragmentation. The excited imido group is at the same time an efficient electron acceptor and can be reduced by numerous donor groups. As a model compound for neutral aliphatic amino acids, the

Syntheses and properties of thienyl-substituted dithienophenazines

• Annemarie Meyer,
• Eva Sigmund,
• Friedhelm Luppertz,
• Gregor Schnakenburg,
• Immanuel Gadaczek,
• Thomas Bredow,
• Stefan-S. Jester and
• Sigurd Höger

Beilstein J. Org. Chem. 2010, 6, 1180–1187, doi:10.3762/bjoc.6.135

• assumption that the electron rich thiophene units act as electron donors and the electron poor phenazine unit as an electron acceptor in this intramolecular CT-complex. This CT state can also be observed in 16 (Figure 2e), but here the calculated difference between the S1 energies of 12a and 16 (0.27 eV) is

Self-assembly and semiconductivity of an oligothiophene supergelator

• Pampa Pratihar,
• Suhrit Ghosh,
• Vladimir Stepanenko,
• Sameer Patwardhan,
• Ferdinand C. Grozema,
• Laurens D. A. Siebbeles and
• Frank Würthner

Beilstein J. Org. Chem. 2010, 6, 1070–1078, doi:10.3762/bjoc.6.122

• electron-rich quaterthiophene derivative with the electron acceptor [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) revealed a nanoscale segregated assembly of the individual building blocks in the blend. Keywords: charge transport; hydrogen bonding; oligothiophene; organogel; self-assembly

Donor-acceptor substituted phenylethynyltriphenylenes – excited state intramolecular charge transfer, solvatochromic absorption and fluorescence emission

• Ritesh Nandy and
• Sethuraman Sankararaman

Beilstein J. Org. Chem. 2010, 6, 992–1001, doi:10.3762/bjoc.6.112

• show that the triphenylene chromophore can act either as an electron donor or as an electron acceptor in the ICT process, depending upon the nature of substituent on the phenyl ring. Derivatives 1e and 1g are potential candidates for use as solvent polarity probes. However, their performance is only

EPR and pulsed ENDOR study of intermediates from reactions of aromatic azides with group 13 metal trichlorides

• Giorgio Bencivenni,
• Riccardo Cesari,
• Daniele Nanni,
• Hassane El Mkami and
• John C. Walton

Beilstein J. Org. Chem. 2010, 6, 713–725, doi:10.3762/bjoc.6.84

• the ET step 12 → 13 was inhibited by the presence of the electron acceptor CN group. Several mechanisms have been proposed in the literature for the formation of ‘dimers’ from anilines. These include [42][43][44]: (i) initial formation of the radical cation ArNH2+• which then couples with more aniline

Convenient methods for preparing π-conjugated linkers as building blocks for modular chemistry

• Jiří Kulhánek,
• Filip Bureš and
• Miroslav Ludwig

Beilstein J. Org. Chem. 2009, 5, No. 11, doi:10.3762/bjoc.5.11

• ], organic light-emitting diodes (OLED) [9] or functional polymers [10][11][12][13]. A typical push-pull chromophore consists of a polar A-π-D system with a planar π-system end-capped by a strong electron donor (D) and a strong electron acceptor (A). The π-conjugated system ensuring charge-transfer (CT

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

• -hexylthiophene) (P3HT) as the electron-donor and diarylmethanofullerene derivatives as the electron-acceptor material were examined. The {(methoxycarbonyl)phenyl[bis(octyloxy)phenyl]methano}fullerene showed power conversion efficiency as high as PCBM, but had higher solubility in a variety of organic solvents

• [19]. These first reduction potential data showed that the diarylmethanofullerene derivatives can be a better electron acceptor than PCBM [27]. Photovoltaic Devices A series of solar cells was fabricated with P3HT as the electron-donor and diarylmethanofullerene derivatives as the electron-acceptor

Synthesis and redox behavior of new ferrocene- π-extended- dithiafulvalenes: An approach for anticipated organic conductors

• Abdelwareth A. O. Sarhan,
• Omar F. Mohammed and
• Taeko Izumi

Beilstein J. Org. Chem. 2009, 5, No. 6, doi:10.3762/bjoc.5.6

• characterized a donor-acceptor dyad system involving tetrathiafulvalene (TTF) as electron donor attached by a flexible spacer to perylene derivatives as electron acceptor [5]. They have shown that the fluorescence of the tetrathiafulvalene–perylene derived dyad can be reversibly modulated by the transformation

Photosonochemical catalytic ring opening of α-epoxyketones

• Hamid R. Memarian and
• Ali Saffar-Teluri

Beilstein J. Org. Chem. 2007, 3, No. 2, doi:10.1186/1860-5397-3-2

• ] acetone [39] and acetic acid solutions. [40] Our recent study with 1-benzyl-2,4,6-triphenylpyridinium tetrafluoroborate (NBTPT) 2 as weaker electron-acceptor compared with TPT (nitrogen vs. oxygen) for highly diastereoselective ring opening of α-epoxyketones in acetone [20] leads us to investigate

• α-epoxyketones and also the electron-acceptor ability of NBTPT on the diastereoselectivity of reaction. Results and Discussion Photo-induced reactions of α-epoxyketones 1a-f with 2 in methanol solution produced a mixture of MeOH-adducts 3a-f and 4a-f (Scheme 1). It should be noted that sonication of

• intermediates 5–7 in the photocatalytic ring opening of α-epoxyketones by TPT as strong electron acceptor due to complete electron transfer from α-epoxyketones to excited TPT (Scheme 2). A comparison of the ultra-violet data of 1a-f with NBTPT presented in Table 2 shows that under the reaction conditions