Structure–property relationships in dicyanopyrazinoquinoxalines and their hydrogen-bonding-capable dihydropyrazinoquinoxalinedione derivatives

• Tural N. Akhmedov,
• Ajeet Kumar,
• Daken J. Starkenburg,
• Kyle J. Chesney,
• Khalil A. Abboud,
• Novruz G. Akhmedov,
• Jiangeng Xue and
• Ronald K. Castellano

Beilstein J. Org. Chem. 2024, 20, 1037–1052, doi:10.3762/bjoc.20.92

• * level of theory (depicted in Figure 4 and Figure 5). Figure 4 reveals that the HOMOs of 1a–7a are predominantly localized on the π-donor units, such as benzene and naphthalene, with an illustration in the case of 6a. On the contrary, the LUMOs are delocalized across the entire π-systems, while also

Ortho-ester-substituted diaryliodonium salts enabled regioselective arylocyclization of naphthols toward 3,4-benzocoumarins

• Ke Jiang,
• Cheng Pan,
• Limin Wang,
• Hao-Yang Wang and
• Jianwei Han

Beilstein J. Org. Chem. 2024, 20, 841–851, doi:10.3762/bjoc.20.76

• variety of 3,4-benzocoumarin derivatives. Our investigations commenced with 2-naphthol (1), and the results are presented in Table 2. Various substituted naphthols with a broad range of substituents on the naphthalene unit were well tolerated in the reaction, affording the corresponding products 3aa–aq in

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

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

• 6-membered rings containing a sulfoxide moiety. For instance, Grainger and co-workers designed a series of naphthotrithiin-2-oxides, such as 47, to act as SO transfer reagents (Scheme 13) [79]. These triplet SO precursors were prepared by treatment of 1,8-naphthalene dithiols with thionyl chloride

• , along with the 5-membered 1,8-naphthalene disulfide 49 resulting from the ring contraction of precursor 47. Such SO transfer process, favoured by the peri-interaction existing in the trisulfide-2-oxide substrate, was also successfully promoted by light and the cyclic sulfoxide 50 was obtained under

Substitution reactions in the acenaphthene analog of quino[7,8-h]quinoline and an unusual synthesis of the corresponding acenaphthylenes by tele-elimination

• Ekaterina V. Kolupaeva,
• Narek A. Dzhangiryan,
• Alexander F. Pozharskii,
• Oleg P. Demidov and
• Valery A. Ozeryanskii

Beilstein J. Org. Chem. 2024, 20, 243–253, doi:10.3762/bjoc.20.24

• , Pushkin str. 1a, 355017 Stavropol, Russian Federation 10.3762/bjoc.20.24 Abstract The possibility of functionalization of dipyrido[3,2-e:2′,3′-h]acenaphthene containing a quino[7,8-h]quinoline fragment and being a highly basic diazine analog of 1,8-bis(dimethylamino)naphthalene (“proton sponge”) has been

• pyridine rings, the naphthalene core at positions 5(8) and the CH2CH2 bridge (dehydrogenation) undergo chemical modifications under mild conditions, giving the corresponding acenaphthylenes. The latter can also be obtained in an unusual way by tele-elimination from 5,8-dibromodipyridoacenaphthene by

• forced to strongly repel each other in space, can lead to a sharp increase in basicity [8]. Thus, quino[7,8-h]quinoline (3), first obtained in the Staab group [9], already exceeds in basicity not only quinoline itself, but also 1,8-bis(dimethylamino)naphthalene (1, “proton sponge”) (Scheme 1; pKa values

Photochromic derivatives of indigo: historical overview of development, challenges and applications

• Gökhan Kaplan,
• Zeynel Seferoğlu and
• Daria V. Berdnikova

Beilstein J. Org. Chem. 2024, 20, 228–242, doi:10.3762/bjoc.20.23

• using heme-containing oxygenases (cytochrome P450 monooxygenases, styrene/indole monooxygenases, flavin-containing monooxygenases, Baeyer–Villiger monooxygenases, etc.) or non-heme iron oxygenases (naphthalene dioxygenases, multicomponent phenol hydroxylases) [5][6][7][8]. The synthetic approaches

Copper-promoted C5-selective bromination of 8-aminoquinoline amides with alkyl bromides

• Changdong Shao,
• Chen Ma,
• Li Li,
• Jingyi Liu,
• Yanan Shen,
• Chen Chen,
• Qionglin Yang,
• Tianyi Xu,
• Zhengsong Hu,
• Yuhe Kan and
• Tingting Zhang

Beilstein J. Org. Chem. 2024, 20, 155–161, doi:10.3762/bjoc.20.14

• trimethylgallic acid bearing multiple methoxy groups afforded the desired product 3ma in excellent yield (99%). Noteworthy to mention, substrates containing naphthalene, furan, and thiophene rings also efficiently underwent reaction leading to the quinoline C5-brominated products in excellent yields (3na–pa). In

• contrast, side products, substituted on the naphthalene, furan, or thiophene ring were not detected. This protocol was also compatible with linear, branched, and cyclic aliphatic acid-derived substrates (3qa–va). Surprisingly, small ring-containing substrates displaying significant ring strain were stable

Biphenylene-containing polycyclic conjugated compounds

• Cagatay Dengiz

Beilstein J. Org. Chem. 2023, 19, 1895–1911, doi:10.3762/bjoc.19.141

• through the pyrolysis of indane-1,2,3-trione. When BBD 13 was subjected to reflux conditions with bis(cyanomethyl) compounds 14a (a benzene derivative) and 14b (a naphthalene derivative) in acetonitrile, the desired POAs 15a and 15b were obtained with yields of 25% and 48%, respectively (Scheme 2). It was

• )2C6H3, (c) H), followed by aromatization in acidic conditions, resulted in the formation of three [3]naphthalene regioisomers 43a–c, 44a–c, and 45a–c with excellent yields of up to 94%. The synthesized PAHs 43a, 44a, and 45a with diverse geometries exhibited interesting absorption and emission

• from benzene (53a), naphthalene (53b), and anthracene (53c) with compound 52, the desired target azaacenes 54a–c were successfully obtained in yields ranging from 68% to 84% (Scheme 11). As anticipated, there was a notable red shift observed from 54a to 54c, which can be attributed to the expansion of

Quinoxaline derivatives as attractive electron-transporting materials

• Zeeshan Abid,
• Liaqat Ali,
• Sughra Gulzar,
• Faiza Wahad,
• Raja Shahid Ashraf and
• Christian B. Nielsen

Beilstein J. Org. Chem. 2023, 19, 1694–1712, doi:10.3762/bjoc.19.124

• ]. Similarly, Grobelny et al.'s work provides valuable insights into the impact of two quinoxaline derivatives, hexyloxy-substituted diphenylquinoxaline (HPQ) and naphthalene-fused-quinoxaline (NFQ), as auxiliary acceptors on DSSC performance. The comparison between Qx34 and Qx35 highlights the importance of

Cyclodextrins permeabilize DPPC liposome membranes: a focus on cholesterol content, cyclodextrin type, and concentration

• Ghenwa Nasr,
• Hélène Greige-Gerges,
• Sophie Fourmentin,
• Abdelhamid Elaissari and
• Nathalie Khreich

Beilstein J. Org. Chem. 2023, 19, 1570–1579, doi:10.3762/bjoc.19.115

• sulforhodamine B were purchased from Sigma-Aldrich, USA. 4-Amino-3-hydroxy-1-naphthalene sulfonic acid was purchased from Fluka, India. Sulfuric acid was purchased from ACROS Organics, Belgium and diethyl ether was purchased from VWR-Prolabo Chemicals, Belgium. Liposomes preparation, extrusion, and purification

Morpholine-mediated defluorinative cycloaddition of gem-difluoroalkenes and organic azides

• Tzu-Yu Huang,
• Mario Djugovski,
• Sweta Adhikari,
• Destinee L. Manning and
• Sudeshna Roy

Beilstein J. Org. Chem. 2023, 19, 1545–1554, doi:10.3762/bjoc.19.111

• cyano (3d) at the para-position, were amenable to the reaction conditions affording the product in 52% yield. Bulky groups, such as naphthalene were also suitable forming product 3e in 57% yield, highlighting the functional group tolerability of this reaction. Next, the scope of the reaction for aryl

Photoredox catalysis harvesting multiple photon or electrochemical energies

• Mattia Lepori,
• Simon Schmid and
• Joshua P. Barham

Beilstein J. Org. Chem. 2023, 19, 1055–1145, doi:10.3762/bjoc.19.81

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

• the prefused building block in a 49% yield. Then naphthalene and phenanthrene residues were introduced into compound 33 through Suzuki coupling reaction, the corresponding precursors 34 and 36 were obtained respectively in high yields. The final cyclodehydrogenation using DDQ and TfOH proceeded

Synthesis, structure, and properties of switchable cross-conjugated 1,4-diaryl-1,3-butadiynes based on 1,8-bis(dimethylamino)naphthalene

• Semyon V. Tsybulin,
• Ekaterina A. Filatova,
• Alexander F. Pozharskii,
• Valery A. Ozeryanskii and
• Anna V. Gulevskaya

Beilstein J. Org. Chem. 2023, 19, 674–686, doi:10.3762/bjoc.19.49

• two 7-(arylethynyl)-1,8-bis(dimethylamino)naphthalene fragments was prepared via the Glaser–Hay oxidative dimerization of 2-ethynyl-7-(arylethynyl)-1,8-bis(dimethylamino)naphthalenes. The oligomers synthesized in this way are cross-conjugated systems, in which two conjugation pathways are possible: π

• -conjugation of 1,8-bis(dimethylamino)naphthalene (DMAN) fragments through a butadiyne linker and a donor–acceptor aryl–C≡C–DMAN conjugation path. The conjugation path can be “switched” simply by protonation of DMAN fragments. X-ray diffraction, UV–vis spectroscopy and cyclic voltammetry are applied to analyze

• the extent of π-conjugation and the efficiency of particular donor–acceptor conjugation path in these new compounds. X-ray structures and absorption spectra of doubly protonated tetrafluoroborate salts of the oligomers are also discussed. Keywords: 1,8-bis(dimethylamino)naphthalene; cross-conjugated

Transition-metal-catalyzed domino reactions of strained bicyclic alkenes

• Austin Pounder,
• Eric Neufeld,
• Peter Myler and
• William Tam

Beilstein J. Org. Chem. 2023, 19, 487–540, doi:10.3762/bjoc.19.38

• 5.0 equivalents of Cs2CO3 provided the naphthalene core via sequential dehydration. Based on preliminary mechanistic experiments, the authors proposed the reaction begins with the oxidation of Co(II) to Co(III) by O2. MHP-directed C–H activation of the ortho-C–H position generates 90 which can

• reaction to afford the naphthalene product 88a. Inspired by Zhao’s seminal report on the racemic carboamination of bicyclic alkenes [53], the Cramer laboratory studied the Co-catalyzed enantioselective carboamination of bicyclic alkenes 1 via C–H functionalization in 2021 (Scheme 17) [54]. The authors

• azabicyclic alkenes 30 (Scheme 29) [75]. When investigating the reaction with oxabenzonorbornadiene (30b), the resulting product was found to exclusively be the dehydrated 2-naphthalene derivative 166. It was found that the addition of pivalic acid greatly improved the yield, likely due to its facilitation of

Transition-metal-catalyzed C–H bond activation as a sustainable strategy for the synthesis of fluorinated molecules: an overview

• Louis Monsigny,
• Floriane Doche and
• Tatiana Besset

Beilstein J. Org. Chem. 2023, 19, 448–473, doi:10.3762/bjoc.19.35

• allowing the formation of a C(sp2)–ORF bond through palladium-catalyzed C–H bond activation [169]. Using Pd(OPiv)2 as the catalyst in the presence of PhI(OAc)2 (PIDA), the naphthalene sulfoxide 43a was 2,2,2-trifluoroethoxylated in 82% yield (Scheme 21). The substituent of the sulfoxide part does not

• -sulfonylbenzamides reported by the group of Ji and Li [150]. a50 °C. b15 equiv TFA. c5 equiv TFA. dN-acetylglycine (60 mol %). Ns: 4-nitrobenzenesulfonyl. Pd(II)-catalyzed selective 2,2,2-trifluoroethoxylation and other fluoroalkoxylations of naphthalene sulfoxide derivatives reported by the group of Yorimitsu [169

Preparation of β-cyclodextrin/polysaccharide foams using saponin

• Max Petitjean and
• José Ramón Isasi

Beilstein J. Org. Chem. 2023, 19, 78–88, doi:10.3762/bjoc.19.7

• complexing with the PAH and having repulsive interactions with soil [21]. A large quantity of HOCs have been studied, such as naphthalene or fluoranthene [19]. The authors reported also the possibility of remediation of heavy metals by saponins [22]. Therefore, saponins are useful in soil washing

Improving the accuracy of ³¹P NMR chemical shift calculations by use of scaling methods

• William H. Hersh and
• Tsz-Yeung Chan

Beilstein J. Org. Chem. 2023, 19, 36–56, doi:10.3762/bjoc.19.4

• for the P–P-bonded compounds was that of PB in 8 of up to roughly 40 ppm. An alternative hypothesis for this deviation might be that it could be due to multiple P–C bond character rather than the P–P bond itself, due to π overlap of dicoordinate PB with the naphthalene ring. The MAD/RMSD values for

Electrochemical vicinal oxyazidation of α-arylvinyl acetates

• Yi-Lun Li,
• Zhaojiang Shi,
• Tao Shen and
• Ke-Yin Ye

Beilstein J. Org. Chem. 2022, 18, 1026–1031, doi:10.3762/bjoc.18.103

• ), chloro (16), and bromo (17), proceeded with the anticipated reactivity less efficiently (30–48% yields). The presence of other electron-withdrawing groups, such as CO2Me (18) and OCF3 (19), exhibited similar negative effects on the reaction yields. Naphthalene (20), thiophene (21), benzothiophene (22

Electrochemical and spectroscopic properties of twisted dibenzo[g,p]chrysene derivatives

• Tomoya Imai,
• Ryuhei Akasaka,
• Naruhiro Yoshida,
• Toru Amaya and
• Tetsuo Iwasawa

Beilstein J. Org. Chem. 2022, 18, 963–971, doi:10.3762/bjoc.18.96

• , Otsu, Shiga, 520-2194, Japan 10.3762/bjoc.18.96 Abstract Dibenzo[g,p]chrysene (DBC), which consists of a twisted naphthalene core with four fused benzene rings, is a promising framework for organic electronic materials. Therefore, the research for structure–property relationships is important for the

• design of DBC-based materials. Here, the electrochemical and spectroscopic properties of DBC derivatives were investigated, and the effects of substituents and torsion of the naphthalene moiety were examined based on density functional theory (DFT) calculations. All the substituted DBC derivatives showed

• the benzene ring because of the steric repulsion of substituents on both sides. More specifically, the inductive effect of the MeO group is dominant rather than the mesomeric effect when the substituent is located at both sides of the MeO group. Concerning the torsion of the naphthalene moiety, the

Electroreductive coupling of 2-acylbenzoates with α,β-unsaturated carbonyl compounds: density functional theory study on product selectivity

• Naoki Kise and
• Toshihiko Sakurai

Beilstein J. Org. Chem. 2022, 18, 956–962, doi:10.3762/bjoc.18.95

• vinyl ketone (2b) and subsequent treatment with 1 M HCl afforded phthalides 5a–h in moderate to good yields and naphthalene-1-ols 3’ corresponding to cyclized products 3 were not formed at all (Table 2). The Ep values of substrates 1a–h were observed to be in the range from −1.74 to −1.96 V versus SCE

Thiophene/selenophene-based S-shaped double helicenes: regioselective synthesis and structures

• Mengjie Wang,
• Lanping Dang,
• Wan Xu,
• Zhiying Ma,
• Liuliu Shao,
• Guangxia Wang,
• Chunli Li and
• Hua Wang

Beilstein J. Org. Chem. 2022, 18, 809–817, doi:10.3762/bjoc.18.81

• annulene [12], and twisted naphthalene as central spacers [19]. As its close analogue, selenophene has properties very similar to those of thiophene. Fused aromatic compounds containing selenophene units show favorable optical and electrochemical properties and improved charge transport characteristics in

• S21). However, after the formation of the naphthalene ring, the α-position is the most likely site for reaction (Supporting Information File 1, Figure S22). Therefore, after the double oxidative photocyclization of compound 5a, product DH-1 is mainly obtained. The predicted result of the double

• helicenes have the same configuration and bend toward the same direction on the same side of the shared naphthalene ring (Figure 3C and D). Both products DH-1 or DH-2 feature a pair of enantiomers MM and PP in their unit cell (see Supporting Information File 2, Figures S2 and S6). The crystal parameters of

Synthesis of α-(perfluoroalkylsulfonyl)propiophenones: a new set of reagents for the light-mediated perfluoroalkylation of aromatics

• Durbis J. Castillo-Pazos,
• Juan D. Lasso and
• Chao-Jun Li

Beilstein J. Org. Chem. 2022, 18, 788–795, doi:10.3762/bjoc.18.79

• ), both in less than 6 hours (Scheme 5). Unsubstituted arenes such as naphthalene were well tolerated in this methodology and produced 72% isolated yield of the perfluorohexylated product 11b. The radical addition to unsubstituted benzene was also found to be possible affording perfluorooctylated product

DDQ in mechanochemical C–N coupling reactions

• Shyamal Kanti Bera,
• Rosalin Bhanja and
• Prasenjit Mal

Beilstein J. Org. Chem. 2022, 18, 639–646, doi:10.3762/bjoc.18.64

• reacted smoothly with various substituted aldehydes (containing a bromo, fluoro, hydroxy, chloro, ethyl, or methyl group) affording the corresponding products 5b–g with good to excellent yields. Also, 3,4,5-trimethoxy-, 2,4,6-trimethyl-, anthracene-9-yl-, and naphthalene-1-yl-substituted benzaldehydes

Menadione: a platform and a target to valuable compounds synthesis

• Acácio S. de Souza,
• Ruan Carlos B. Ribeiro,
• Dora C. S. Costa,
• Fernanda P. Pauli,
• David R. Pinho,
• Matheus G. de Moraes,
• Fernando de C. da Silva,
• Luana da S. M. Forezi and
• Vitor F. Ferreira

Beilstein J. Org. Chem. 2022, 18, 381–419, doi:10.3762/bjoc.18.43

• hydroquinone ethers [87]. The combination of tert-butyl hydroperoxide and poly(bis-1,2-phenyl)diselenide was the one that showed the best result: 90% yield after 12 h reaction and recrystallization (Table 3, entry 3). Construction of the naphthoquinone ring In addition to the oxidation of naphthalene