Charge carrier transport in perylene-based and pyrene-based columnar liquid crystals

• Alessandro L. Alves,
• Simone V. Bernardino,
• Carlos H. Stadtlober,
• Edivandro Girotto,
• Giliandro Farias,
• Rodney M. do Nascimento,
• Sergio F. Curcio,
• Thiago Cazati,
• Marta E. R. Dotto,
• Juliana Eccher,
• Leonardo N. Furini,
• Hugo Gallardo,
• Harald Bock and
• Ivan H. Bechtold

Beilstein J. Org. Chem. 2023, 19, 1755–1765, doi:10.3762/bjoc.19.128

• -shifted in the film. These results indicate molecular π-stacking aggregation and excimer formation on the films [2]. The PL in film was obtained as a function of temperature (Figure 4). The observed reduction of the PL intensity on heating is expected for organic semiconductors due to self-quenching

• solution and in spin-coated films for compounds 1 (a) and 2 (b). The PL was excited at the wavelength of maximum absorption. PL as a function of temperature for 1 (a) and 2 (b) casting films on heating. Left: PL spectra; right: intensity of the PL maximum. The PL was excited at the wavelength of maximum

Unprecedented synthesis of a 14-membered hexaazamacrocycle

• Anastasia A. Fesenko and
• Anatoly D. Shutalev

Beilstein J. Org. Chem. 2023, 19, 1728–1740, doi:10.3762/bjoc.19.126

• under reflux for 23 h. After the reaction had completed (monitored by 1H NMR spectroscopy), the obtained solution was concentrated under water pump vacuum upon heating in a water bath at 65 °C. The product was extracted from the resulting dense brown oil by trituration 4 times with a mixture of ether

• heating rate) [lit [40] mp 269–270 °C (MeOH)]; IR (KBr, cm−1) ν: 3423 (br s), 3365 (s), 3307 (br s), 3182 (br s), 1626 (sh), 1596 (vs), 1555 (s), 1547 (sh), 1242 (s), 1164 (s), 965 (s); 1H NMR (600.13 MHz, DMSO-d6) δ 11.82 (d, 3J = 11.2 Hz, 2Н, two NH), 8.01 (q, 4J = 0.5 Hz, 2Н, H-3 and H-11), 7.47 (d, 3J

Effects of the aldehyde-derived ring substituent on the properties of two new bioinspired trimethoxybenzoylhydrazones: methyl vs nitro groups

• Dayanne Martins,
• Roberta Lamosa,
• Talis Uelisson da Silva,
• Carolina B. P. Ligiero,
• Sérgio de Paula Machado,
• Daphne S. Cukierman and
• Nicolás A. Rey

Beilstein J. Org. Chem. 2023, 19, 1713–1727, doi:10.3762/bjoc.19.125

• of the solid samples in spectroscopic grade potassium bromide (KBr). Thermogravimetric analyses were performed using a Pyris 1 TGA thermoanalyzer (Perkin-Elmer), at 10 °C min−1 heating rate, under nitrogen flow (20 mL min−1), from 25 to 350 °C. Melting points were determined in triplicate using a

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

• for 6 h to afford the monocycloaddition compounds. Without isolation, the reaction mixtures were then used for the N-propargylation in the presence of K2CO3 under microwave heating at 110 °C for 1 h to give triazolobenzodiazepines 21a–f in 35–65% yields with 2:1 to 7:1 dr (Scheme 13). Other than 2

A deep-red fluorophore based on naphthothiadiazole as emitter with hybridized local and charge transfer and ambipolar transporting properties for electroluminescent devices

• Suangsiri Arunlimsawat,
• Patteera Funchien,
• Pongsakorn Chasing,
• Atthapon Saenubol,
• Taweesak Sudyoadsuk and
• Vinich Promarak

Beilstein J. Org. Chem. 2023, 19, 1664–1676, doi:10.3762/bjoc.19.122

• illumination). a) DSC and TGA thermograms measured at a heating rate of 10 °C min−1 under N2 flow. b) Cyclic voltammogram (CV) and differential pulse voltammogram (DPV) analyzed in dry CH2Cl2 at a scan rate of 50 mV s−1 under an argon atmosphere (insert: HOMO/HOMO−1/LUMO orbitals). a) Schematic structure of

Radical chemistry in polymer science: an overview and recent advances

• Zixiao Wang,
• Feichen Cui,
• Yang Sui and
• Jiajun Yan

Beilstein J. Org. Chem. 2023, 19, 1580–1603, doi:10.3762/bjoc.19.116

• 1830s, Charles Goodyear invented vulcanized rubber. By heating natural rubber with lead oxide and sulfur, the temperature-sensitive rubber became a more stable material, even at high and low temperatures, while keeping the elasticity, plasticity, insulation, and other excellent characteristics [124

• diazonium salts produces highly reactive aryl radicals (Scheme 18) [153]. The chemical conversion can be initiated by electrochemical reduction [154], a reducing agent [155][156][157], a base [158], heating [159], or photochemically [160]. Aryl radicals may act as a halogen abstractor for alkyl halides and

Secondary metabolites of Diaporthe cameroonensis, isolated from the Cameroonian medicinal plant Trema guineensis

• Bel Youssouf G. Mountessou,
• Élodie Gisèle M. Anoumedem,
• Blondelle M. Kemkuignou,
• Yasmina Marin-Felix,
• Frank Surup,
• Marc Stadler and
• Simeon F. Kouam

Beilstein J. Org. Chem. 2023, 19, 1555–1561, doi:10.3762/bjoc.19.112

• sulfuric acid before heating. LC–MS chromatograms were recorded with an UltiMate 3000 Series uHPLC (Thermo Fischer Scientific) using a C18 Acquity UPLC BEH column (2.1 × 50 mm, 1.7 µm) connected to an amazon speed ESI-Iontrap-MS (Bruker). Semi-preparative and/or preparative HPLC systems on normal and

Synthesis and biological evaluation of Argemone mexicana-inspired antimicrobials

• Jessica Villegas,
• Bryce C. Ball,
• Katelyn M. Shouse,
• Caleb W. VanArragon,
• Ashley N. Wasserman,
• Hannah E. Bhakta,
• Allen G. Oliver,
• Danielle A. Orozco-Nunnelly and
• Jeffrey M. Pruet

Beilstein J. Org. Chem. 2023, 19, 1511–1524, doi:10.3762/bjoc.19.108

• through the use of additional NaOH and refluxing the crude alkylation mixture. After heating for 3 h, the desired intermediates were recovered in acceptable yields over this two-step one-pot sequence. The amide hydrolysis of 7 and 8 to the desired free naphthylamines 9 and 10 proved challenging, but was

N-Sulfenylsuccinimide/phthalimide: an alternative sulfenylating reagent in organic transformations

• Fatemeh Doraghi,
• Seyedeh Pegah Aledavoud,
• Mehdi Ghanbarlou,
• Bagher Larijani and
• Mohammad Mahdavi

Beilstein J. Org. Chem. 2023, 19, 1471–1502, doi:10.3762/bjoc.19.106

• traditional heating methods. In the meanwhile, Qiu and Xu et al. reported the coupling reaction between diazo compounds 163 and N-sulfenylsuccinimides 1 under catalyst-, base-, and additive-free conditions (Scheme 71) [101]. The reaction proceeded via a radical pathway, in which a free carbene was generated

• under heating, followed by the formation of ylide, N–S bond cleavage, and C–N bond formation along with the release of N2. In 2019, Sun and co-workers introduced an unprecedented method for the synthesis of isothiourea derivatives via the activation of diaryl/alkyl disulfides 47 with N-halosuccinimides

Cyclization of 1-aryl-4,4,4-trichlorobut-2-en-1-ones into 3-trichloromethylindan-1-ones in triflic acid

• Vladislav A. Sokolov,
• Andrei A. Golushko,
• Irina A. Boyarskaya and
• Aleksander V. Vasilyev

Beilstein J. Org. Chem. 2023, 19, 1460–1470, doi:10.3762/bjoc.19.105

• was found that enones 2 were transformed into the corresponding 3-trichloromethylindan-1-ones 3 upon heating in neat TfOH at 80 °C for 2–10 h (Scheme 5). Under the same reaction conditions, hydroxy ketones 1 were cyclized into indanones 3 as well (Scheme 6). The structure of compound 3a was confirmed

Application of N-heterocyclic carbene–Cu(I) complexes as catalysts in organic synthesis: a review

• Nosheen Beig,
• Varsha Goyal and
• Raj K. Bansal

Beilstein J. Org. Chem. 2023, 19, 1408–1442, doi:10.3762/bjoc.19.102

• anionic hybrid NHC, “IMes-acac” consisting of fused diaminocarbene and acetylacetonato units. The latter afforded a series of representative Cu(I) complexes through bidentate coordination (Scheme 16) [30]. 1.2 Deprotonation of NHC-precursors with Cu2O Another important and facile method involves heating

• of the NHC-precursor, i.e. an azolium salt with cuprous oxide using a solvent or under microwave conditions (Scheme 17). Kolychev in 2009 attempted the preparation of NHC–Cu(I) complexes via deprotonation by heating of amidinium salt 53 [(7-Dipp)H][Br] with Cu2O in the presence of sodium acetate in

• , Cazin and co-workers reported the synthesis of Cu(I) complexes 61, 63, and 65 of the so-called ‘abnormal’ NHCs (Scheme 21) [35]. Thus, the conventional heating method as well as microwave irradiation methods were employed. The structures of the synthesized complexes were confirmed by X-ray analysis

Synthesis of ether lipids: natural compounds and analogues

• Marco Antônio G. B. Gomes,
• Alicia Bauduin,
• Chloé Le Roux,
• Romain Fouinneteau,
• Wilfried Berthe,
• Mathieu Berchel,
• Hélène Couthon and
• Paul-Alain Jaffrès

Beilstein J. Org. Chem. 2023, 19, 1299–1369, doi:10.3762/bjoc.19.96

• whereas heating it in 75% acetic acid solution produced the deprotected compound but migration of the acyl group from the sn-2 to the sn-3 position lead to an inseparable mixture of regioisomers. A selective desilylation of 12.5 was finally achieved with BF3·Et2O producing 12.6 without migration of the

Organic thermally activated delayed fluorescence material with strained benzoguanidine donor

• Alexander C. Brannan,
• Elvie F. P. Beaumont,
• Nguyen Le Phuoc,
• George F. S. Whitehead,
• Mikko Linnolahti and
• Alexander S. Romanov

Beilstein J. Org. Chem. 2023, 19, 1289–1298, doi:10.3762/bjoc.19.95

• benzonitrile acceptor core. We found that the material is formed as a mixture of the rotational isomers that do not experience interconversion upon heating the 4BGIPN solution in DMSO to 120 °C. Two rotational isomers were successfully crystallized to show different up and down orientations of the

New one-pot synthesis of 4-arylpyrazolo[3,4-b]pyridin-6-ones based on 5-aminopyrazoles and azlactones

• Vladislav Yu. Shuvalov,
• Ekaterina Yu. Vlasova,
• Tatyana Yu. Zheleznova and
• Alexander S. Fisyuk

Beilstein J. Org. Chem. 2023, 19, 1155–1160, doi:10.3762/bjoc.19.83

• ]pyridones 3 obtained by this method vary widely [31][32][33]. Solvent-free reactions are convenient from both economic and environmental points of view. We obtained tetrahydro-1H-pyrazolo[3,4-b]pyridinone 3a by heating 5-aminopyrazole 1 with azlactone 2a in the absence of solvent at 150 °C in 62% yield

• -aminopyrazoles 1, 5, 6 and azlactones 2a–i, followed by heating the resulting intermediate in DMSO in the presence of t-BuOK. Photophysical properties of the obtained compounds were studied. Biologically active 4-arylpyrazolo[3,4-b]pyridin-6-ones. Normalized absorption and fluorescence spectra of solutions of

Synthesis of imidazo[4,5-e][1,3]thiazino[2,3-c][1,2,4]triazines via a base-induced rearrangement of functionalized imidazo[4,5-e]thiazolo[2,3-c][1,2,4]triazines

• Dmitry B. Vinogradov,
• Alexei N. Izmest’ev,
• Angelina N. Kravchenko,
• Yuri A. Strelenko and
• Galina A. Gazieva

Beilstein J. Org. Chem. 2023, 19, 1047–1054, doi:10.3762/bjoc.19.80

• prepare the corresponding carboxylic acids 4 using an aqueous KOH solution. Heating esters 1a,b in an aqueous solution of KOH and subsequent addition of hydrochloric acid led to the corresponding acids 4a,b as the main products. Acids 4a,b were isolated from the mixtures in 17 and 38% yield, respectively

The effect of dark states on the intersystem crossing and thermally activated delayed fluorescence of naphthalimide-phenothiazine dyads

• Liyuan Cao,
• Xi Liu,
• Xue Zhang,
• Jianzhang Zhao,
• Fabiao Yu and
• Yan Wan

Beilstein J. Org. Chem. 2023, 19, 1028–1046, doi:10.3762/bjoc.19.79

• , and NI-PTZ-Ph-O. Temperature range: 25–800 °C, heating rate: 10 °C/min in N2 atmosphere. Femtosecond transient absorption spectra of NI-PTZ-F. (a) Transient absorption spectra and (b) the EADS obtained with global analysis in HEX. Femtosecond transient absorption spectra of NI-PTZ-F-O. (c) Transient

CO₂ complexation with cyclodextrins

• Cecilie Høgfeldt Jessen,
• Jesper Bendix,
• Theis Brock Nannestad,
• Heloisa Bordallo,
• Martin Jæger Pedersen,
• Christian Marcus Pedersen and
• Mikael Bols

Beilstein J. Org. Chem. 2023, 19, 1021–1027, doi:10.3762/bjoc.19.78

• coverage of the bottom. The analysis shown in Figure 3 was started at 28 °C, and was finished at a temperature of 150 °C with a heating rate of 5 °C/min. Determination of dissociation constants between 7 and CD’s. Samples were prepared that consisted of citrate-phosphate buffer (pH 3, 50 mM), 7 (40 μM) and

Synthesis of tetrahydrofuro[3,2-c]pyridines via Pictet–Spengler reaction

• Elena Y. Mendogralo and
• Maxim G. Uchuskin

Beilstein J. Org. Chem. 2023, 19, 991–997, doi:10.3762/bjoc.19.74

• overnight (Table 1, entries 15 and 16). Finally, we found that the optimal reaction time was 5 hours. The yield of the desired product 4a in this case was 67% (Table 1, entry 18). With a shorter time, a slightly reduced reaction yield of 4a was observed, while at longer heating the reaction mixture

Clauson–Kaas pyrrole synthesis using diverse catalysts: a transition from conventional to greener approach

• Dileep Kumar Singh and
• Rajesh Kumar

Beilstein J. Org. Chem. 2023, 19, 928–955, doi:10.3762/bjoc.19.71

• to reduce energy consumption and the carbon footprint. The traditional heating techniques used to synthesize compounds are being replaced by contemporary green alternative energy systems, such as photocatalysis, microwave irradiation, ultrasonic irradiation, grinding, and ball milling processes

• interaction between DES and the amino group enhance the nucleophlicity of the amines. (3) Microwave-assisted reactions Microwave-assisted heating offers a number of advantages over conventional heating, such as greater precision, excellent product yields, and very rapid reaction. This section describes the

• synthesis of N-substituted pyrroles catalyzed by CeCl3∙7H2O. In this reaction, N-arylpyrroles 75 were synthesized from various aniline derivatives 74 by the reaction with 2,5-dimethoxytetrahydrofuran (2) in both microwave irradiation and conventional heating in acetonitrile (Scheme 36). Furthermore, these N

First synthesis of acylated nitrocyclopropanes

• Kento Iwai,
• Rikiya Kamidate,
• Khimiya Wada,
• Haruyasu Asahara and
• Nagatoshi Nishiwaki

Beilstein J. Org. Chem. 2023, 19, 892–900, doi:10.3762/bjoc.19.67

• our study using ethyl acetoacetate (3c) as starting 1,3-dicarbonyl compound according to method b (Scheme 2). After heating an acetonitrile solution of 3c, N-bromosuccinimide, and p-toluenesulfonic acid [7], α-bromoacetoacetate 6c was isolated with a 44% yield after purification of the reaction

Eschenmoser coupling reactions starting from primary thioamides. When do they work and when not?

• Lukáš Marek,
• Jiří Váňa,
• Jan Svoboda and
• Jiří Hanusek

Beilstein J. Org. Chem. 2023, 19, 808–819, doi:10.3762/bjoc.19.61

• formation of products 8a and 8a-Me was observed, but their combined yield was lower than in DMF or MeCN. The introduction of the N-methyl group coming from trimethyl phosphite must occur prior to the dehydration step of the intermediary thiazole 7a because heating of independently prepared 8a with trimethyl

Sulfate radical anion-induced benzylic oxidation of N-(arylsulfonyl)benzylamines to N-arylsulfonylimines

• Joydev K. Laha,
• Pankaj Gupta and
• Amitava Hazra

Beilstein J. Org. Chem. 2023, 19, 771–777, doi:10.3762/bjoc.19.57

• synthetic utility of the developed protocol, a tandem “one-pot” synthesis of N-heterocycles was successfully executed (Scheme 3). Thus, exposition of substrates 1 under the optimized reaction conditions followed by the addition of ortho-substituted anilines 3 and K2S2O8 (1 equiv) and heating the reaction

• cleavage of the peroxy linkage under heating conditions [17]. The hydrogen atom is abstracted from the benzylic position of 1 by SO4·−, generating benzylic radical 1aa [14][15][16]. A single electron transfer (SET) could subsequently occur from 1aa to form the reactive species 1ab. Finally, the base

Honeycomb reactor: a promising device for streamlining aerobic oxidation under continuous-flow conditions

• Masahiro Hosoya,
• Yusuke Saito and
• Yousuke Horiuchi

Beilstein J. Org. Chem. 2023, 19, 752–763, doi:10.3762/bjoc.19.55

• consideration from the time course of the heat of reaction. The adiabatic heating was calculated to be 138 K (see Supporting Information File 1). To suppress the increase of the internal temperature, the amount of AcOH was increased by 40 times (from 3 mL/g to 120 mL/g) for the following evaluation of the

• reaction rate under flow conditions. This dilution suppressed the adiabatic heating to less than 5 K, and the reaction rate could be more precisely evaluated. Evaluation of the reaction rate under continuous-flow conditions The reaction rate was evaluated under continuous-flow conditions using a standard

Construction of hexabenzocoronene-based chiral nanographenes

• Ranran Li,
• Di Wang,
• Shengtao Li and
• Peng An

Beilstein J. Org. Chem. 2023, 19, 736–751, doi:10.3762/bjoc.19.54

• determined for the enantiopure helicenes. For compound 12, the racemization barrier was 24.8 kcal mol−1 at 298 K, which provides a racemization half-life (t1/2) of 24.4 h. For compounds 11 and 13, neither racemization nor decomposition was observed by chiral HPLC after heating hexadecane solutions of each

• racemization was observed by heating the enantiomer for 1 hour at 120 °C. Except for [5]helicene, Narita and co-workers also reported [7]- or [9]helicene-containing chiral NGs [42]. As shown in Scheme 4, dibromo-functionalized 1,2,3,4-tetraphenylbenzene 32 was treated with DDQ and TfOH to produce dibromo 33 as

• the NG precursor 39 by heating dialkyne 38 and tetracyclone 2, which led to two hexarylbenzene units connected by an oxygen linker. Upon treatment of 39 under Scholl reaction conditions (DDQ, TfOH), an oxa-[7]helicene containing chiral NG 40 was obtained in high yield [43]. Meanwhile, they enlarged

Strategies in the synthesis of dibenzo[b,f]heteropines

• David I. H. Maier,
• Barend C. B. Bezuidenhoudt and
• Charlene Marais

Beilstein J. Org. Chem. 2023, 19, 700–718, doi:10.3762/bjoc.19.51

• good yield (80%) by heating 23 in polyphosphoric acid (Scheme 5). Independently, in an effort to synthesise phenothiazine isosteres, Craig et al. [39] prepared 1a via a Wagner–Meerwein rearrangement of 23 with P2O5 (Scheme 5) the following year. The method was used to successfully synthesise

•  8). 2.4 Ring expansion of N-arylindoles (41) The polyphosphoric acid (PPA)-catalysed rearrangement of N-arylindoles 41 was first reported by Tokmakov and Grandberg [48]. The reaction provided moderate yields with a simple 2 step linear sequence from indole 39. The reaction requires heating at

• ] reported the synthesis of substituted dibenzo[b,f]azepines 110 as unexpected products during their investigation of the Catellani reaction. The Pd-catalysed reaction of an aryl iodide 106, bromoaniline 107, norbornadiene (108) and base resulted in the norbornene-azepine intermediate 109. Heating to 130 °C