Isolation and structure determination of a new analog of polycavernosides from marine Okeania sp. cyanobacterium

• Kairi Umeda,
• Naoaki Kurisawa,
• Ghulam Jeelani,
• Tomoyoshi Nozaki,
• Kiyotake Suenaga and
• Arihiro Iwasaki

Beilstein J. Org. Chem. 2024, 20, 645–652, doi:10.3762/bjoc.20.57

• characteristic UV absorption around 270 nm. The molecular formula of 1 was determined to be C44H66O15 based on the HRESIMS data. The NMR data for 1 are summarized in Table 1. The 1H NMR spectrum of compound 1 was similar to those of known polycavernosides but matched none of them, suggesting that 1 was a new

Synthesis of photo- and ionochromic N-acylated 2-(aminomethylene)benzo[b]thiophene-3(2Н)-ones with a terminal phenanthroline group

• Vladimir P. Rybalkin,
• Sofiya Yu. Zmeeva,
• Lidiya L. Popova,
• Irina V. Dubonosova,
• Olga Yu. Karlutova,
• Oleg P. Demidov,
• Alexander D. Dubonosov and
• Vladimir A. Bren

Beilstein J. Org. Chem. 2024, 20, 552–560, doi:10.3762/bjoc.20.47

• change of the solutions from yellow to dark orange. Subsequent selective interaction with AcO− led to the restoration of the initial absorption and emission properties. Thus, the obtained compounds represent dual-mode “on–off–on” switches of optical and fluorescent properties under sequential exposure to

• absorption spectra, induced in one or both directions by absorption of electromagnetic radiation [1][2][3][4]. Due to the different structures and the different optical and emission properties of these forms, photochromic compounds are used in 3D optical memory devices, photoswitches of different types

• -wavelength absorption at 458 nm, while acylation led to a hypsochromic shift of the maximum in compounds 2a–c to 423–426 nm (Table 1). The intensity of this absorption band decreased with increasing steric hindrance in the order R = acetyl (i.e., 2a) > propionyl (i.e., 2b) > phenylacetyl (i.e., 2c). N

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

• arms with planar Pt complexes are parallel and the distance between them allows for the intercalation of another terpy-Pt complex. The guest intercalation coupled with the induction of short-range Pt–Pt interactions was followed by UV–vis absorption and emission spectroscopies with characteristic MMLCT

• chiroptical properties with a large change in the absorption spectra and a bathochromic shift in the emission maximum. This system represents a rare example of a multi-output readout system, showing responses in ECD, fluorescence, and CPL activity. The authors later reported a similar system with a bipyridine

• bearing this time alkynylplatinum(II)–terpyridine arms 21 [53]. The intercalation of an alkynylplatinum(II)–terpyridine complex system results in a large absorption band in the visible domain (λmax,abs = 515 nm) and an enhanced emission band in the infrared (λmax,emission = 780 nm) attributed to the

A new analog of dihydroxybenzoic acid from Saccharopolyspora sp. KR21-0001

• Rattiya Janthanom,
• Yuta Kikuchi,
• Hiroki Kanto,
• Tomoyasu Hirose,
• Arisu Tahara,
• Takahiro Ishii,
• Arinthip Thamchaipenet and
• Yuki Inahashi

Beilstein J. Org. Chem. 2024, 20, 497–503, doi:10.3762/bjoc.20.44

• preparative HPLC of the crude extract, 7.9 mg of 1 was obtained (Scheme 1). Table S1 (Supporting Information File 1) shows the physicochemical properties of 1, which is a yellow oil soluble in MeOH and DMSO. The UV absorption maximum of 1 was at 286 nm (ε = 10238 M−1·cm−1). The molecular formula of 1 was

Pseudallenes A and B, new sulfur-containing ovalicin sesquiterpenoid derivatives with antimicrobial activity from the deep-sea cold seep sediment-derived fungus Pseudallescheria boydii CS-793

• Zhen Ying,
• Xiao-Ming Li,
• Sui-Qun Yang,
• Hong-Lei Li,
• Xin Li,
• Bin-Gui Wang and
• Ling-Hong Meng

Beilstein J. Org. Chem. 2024, 20, 470–478, doi:10.3762/bjoc.20.42

• crystallographic analysis of compounds 1–3 [16]. Compounds 1–3 were crystallized in MeOH. All crystallographic data were collected on a Bruker Smart-1000 or Bruker D8 Venture CCD diffractometer using Cu Kα radiation (λ = 1.54178 Å). The data were corrected for absorption by using the program SADABS [17]. The

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

• [10]CPP and [5]CPP2+ decreased and increased, respectively, upon complex formation and clearly indicate the partial electron transfer from [10]CPP to [5]CPP2+ in the complex. The involvement of a CT in the complex was further supported by the UV–vis–NIR absorption spectra. The complex showed several

• absorption bands in the visible region and characteristic broad absorption bands extending to the NIR region (≈2000 nm) (Figure 4, black line). According to time-dependent density functional theory (DFT) calculations at the ωB97-XD/6-31G* level of theory, the NIR absorption of the most thermodynamically

Green and sustainable approaches for the Friedel–Crafts reaction between aldehydes and indoles

• Periklis X. Kolagkis,
• Eirini M. Galathri and
• Christoforos G. Kokotos

Beilstein J. Org. Chem. 2024, 20, 379–426, doi:10.3762/bjoc.20.36

Mechanisms for radical reactions initiating from N-hydroxyphthalimide esters

• Carlos R. Azpilcueta-Nicolas and
• Jean-Philip Lumb

Beilstein J. Org. Chem. 2024, 20, 346–378, doi:10.3762/bjoc.20.35

• absorption of light, an excited photocatalyst (*PC) engages in single-electron transfer (SET) with either donor (D) or acceptor (A) molecules (Scheme 3) [8][36]. Accordingly, a reductive quenching mechanism (path a) will operate when an excited photocatalyst effects the one-electron oxidation of a

• (B2cat2) [63] (Scheme 15A). UV–vis absorption measurements showed that a mixture of a model NHPI ester with B2cat2 in dimethylacetamide (DMA) formed a new charge-transfer band in the visible region (>390 nm), which was attributed to the formation of EDA complex 74 (Scheme 15B). Under blue light

• absorption spectra of PTH1 was observed, suggesting the formation of a charge transfer complex of the type 88 [68] (Scheme 17A). tert-Butyl radical (64), along with additional 2° and 3° alkyl radicals, resulting from these EDA complexes were harnessed in C(sp3)-heteroatom bond forming reactions [69], and in

Facile approach to N,O,S-heteropentacycles via condensation of sterically crowded 3H-phenoxazin-3-one with ortho-substituted anilines

• Eugeny Ivakhnenko,
• Vasily Malay,
• Pavel Knyazev,
• Nikita Merezhko,
• Nadezhda Makarova,
• Oleg Demidov,
• Gennady Borodkin,
• Andrey Starikov and
• Vladimir Minkin

Beilstein J. Org. Chem. 2024, 20, 336–345, doi:10.3762/bjoc.20.34

• fragment gave rise to the appearance of an additional long-wavelength absorption band with λmax = 520 nm and ε = 9200 M−1⋅сm−1. Subjecting o-phenylenediamines 2с to the reaction with 3H-phenoxazin-3-one makes the simultaneous activation of two principle reaction pathways (SNH and Schiff base formation

• successfully under the conditions applied to the preparation of 14H-quinoxaline[2,3-b]phenoxazines 5. The reaction proceeds readily with o-mercaptoaniline to produce the benzo[5,6][1,4]oxazino[2,3-b]phenothiazine derivative 10c (Scheme 6). Electronic absorption spectra of the prepared 14Н-quinoxaline[2,3-b

• ]phenoxazines 5 and 6 (Table 2, Figures 5–7, and Figures S7–S11, Supporting Information File 1) exhibit broad and high-intensity absorption maxima in the range of 450–550 nm, which encompass the strongest emissive part of the solar spectrum. In contrast to nonfluorescent 6,8-di-tert-butyl-2-(arylamino)-3H

Discovery of unguisin J, a new cyclic peptide from Aspergillus heteromorphus CBS 117.55, and phylogeny-based bioinformatic analysis of UngA NRPS domains

• Sharmila Neupane,
• Marcelo Rodrigues de Amorim and
• Elizabeth Skellam

Beilstein J. Org. Chem. 2024, 20, 321–330, doi:10.3762/bjoc.20.32

• ]+ at m/z 773.4338, calculated for C41H57N8O7+, m/z 773.4345, Δ 0.9 ppm; [M + Na]+ at m/z 795.4162, calculated for C41H56N8O7Na+, m/z 795.4164, Δ 0.3 ppm) and NMR data analysis, corresponding to eighteen indices of hydrogen deficiency. Its UV spectrum exhibited absorption maxima at λmax 219 and 279 nm

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

• stability. Conversely, selenepine 28c and selenepine Se-oxide 29c were quantitatively converted into the seco-HBC 31 by thermal activation at 200 °C for 5 min, as evidenced by UV–visible absorption and HPLC monitoring. SO-extrusion from thiepine S-oxide 29b was also successfully triggered in the solid state

• dinaphthooxanorcaradiene bisimide valence isomer obtained upon electron injection and not its neutral form, as shown by UV–vis absorption and DFT studies. The mechanism of the final release of oxygen still remains unclear. This example shows that a careful molecular design allows endowing chalcogen heteropines with

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

• we analyzed by UV–vis spectroscopy. This peak was assigned as a bis(fulleroid) compound by comparing the spectra with the UV–vis absorption pattern exhibited by previously characterized C70 bis(fulleroids) reported by Murata et al. [43][48]. In addition, a minor peak at a retention time of 20 minutes

Catalytic multi-step domino and one-pot reactions

• Svetlana B. Tsogoeva

Beilstein J. Org. Chem. 2024, 20, 254–256, doi:10.3762/bjoc.20.25

• in the Full Research Paper by Nath and co-workers. The newly synthesized porphyrin derivatives displayed significant red-shifted absorption and emission compared to simple meso-tetraarylporphyrins [14]. The Carlone group reports an Enders-type triple cascade reaction toward cyclohexenals, using

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

• -chromophores” after the shape of the main structural fragment resembling the Latin letter “H” (Figure 4) [19]. The small HOMO–LUMO gap and, thus, the long-wavelength absorption are responsible for the purple color of indigo in vapors, which changes into deep blue color in the crystalline state due to formation

• color of these dyes, as shown by the absorption maxima positions of the substituted indigo derivatives (Table 1) [23][24]. The introduction of the ED (electron-donating) substituents into the para (5,5')- or ortho (7,7')-positions to the electron-donating NH group results in a bathochromic shift of the

• absorption band and increases its intensity, while the presence of the EA (electron-accepting) substituents in these positions leads to a hypsochromic shift (Figure 5). On the contrary, the introduction of the ED substituents at the para (6,6')- or ortho (4,4')-positions to the electron-withdrawing C=O group

Perspectives on push–pull chromophores derived from click-type [2 + 2] cycloaddition–retroelectrocyclization reactions of electron-rich alkynes and electron-deficient alkenes

• Michio Yamada

Beilstein J. Org. Chem. 2024, 20, 125–154, doi:10.3762/bjoc.20.13

• , the ensuing RE process yields the corresponding TCBD derivatives. The resulting TCBDs and related products exhibit strong light absorption, resulting from the intramolecular charge transfer (ICT) in the visible region; they also exhibit a rich redox chemistry [11]. In the [2 + 2] CA–RE reaction of

• DCNQ unit or where a methyl group on the C60 surface is replaced by a hydrogen atom. The C60–TCBD conjugate 57 and C60–DCNQ conjugate 58 exhibited substantial optical rotations at 589 nm, presenting +770 for (P)-57 and +5,800 for (P)-58. In concordance, robust Cotton effects related to ICT absorption

• particular, Diederich et al. conducted a theoretical investigation on the photophysical properties of 1,1,2,4,4-pentacyanobuta-1,3-diene (PCBD) (63) [134]. Compound 63 and the TCBD 64 demonstrated no discernible luminescence at room temperature and 77 K (Figure 4). Transient absorption spectral measurements

Photoinduced in situ generation of DNA-targeting ligands: DNA-binding and DNA-photodamaging properties of benzo[c]quinolizinium ions

• Julika Schlosser,
• Olga Fedorova,
• Yuri Fedorov and
• Heiko Ihmels

Beilstein J. Org. Chem. 2024, 20, 101–117, doi:10.3762/bjoc.20.11

• spectrometry. In all cases, the E-configuration of the alkene double bonds was indicated by characteristic coupling constants of the alkene protons (3JH–H = 16 Hz). Absorption properties and photoreactions of styrylpyridine derivatives In acetonitrile solution, the styrylpyridines 2a–g exhibited long

• -wavelength absorption bands with maxima in a range from λmax = 333 nm for the ethyl-substituted compound 2f to λmax = 394 nm for the nitro-substituted derivative 2a (Figure 1A, Supporting Information File 1, Table S1). As compared with the absorption maximum of the parent compound at λmax = 330 nm [20], the

• derivatives 2b–g showed a slight bathochromic shift mostly in the range of λmax = 333–360 nm, whereas for the nitro-substituted compound 2a a stronger red shift of the absorption maximum was observed, presumably caused by the strong electron-withdrawing property of the nitro group resulting in a more

Optimizing reaction conditions for the light-driven hydrogen evolution in a loop photoreactor

• Pengcheng Li,
• Daniel Kowalczyk,
• Johannes Liessem,
• Mohamed M. Elnagar,
• Dariusz Mitoraj,
• Radim Beranek and
• Dirk Ziegenbalg

Beilstein J. Org. Chem. 2024, 20, 74–91, doi:10.3762/bjoc.20.9

• absorption According to the Beer–Lambert law, the absorption of light in a solution can be described by Equation 1 [33]. where A is the absorbance, I0 is the intensity of light entering the solution perpendicularly to one face, Id is the intensity of light exiting the solution, ε is the extinction

• shot under red light, which matched the absorption properties of the dye, to obtain optimal optical visualization. Digital images extracted from videos (see Supporting Information File 2) were processed with the Python OpenCV package to quantify the mixing time (see Supporting Information File 3

• electronic absorption measurement Light attenuation in the reaction solution was measured for different optical paths (0.2, 0.5, 1, 2, 3, and 5 cm) with the same concentration of photocatalyst in water and methanol solution as used for photocatalytic hydrogen evolution. Cuvettes were used to model the

Multi-redox indenofluorene chromophores incorporating dithiafulvene donor and ene/enediyne acceptor units

• Christina Schøttler,
• Kasper Lund-Rasmussen,
• Line Broløs,
• Philip Vinterberg,
• Ema Bazikova,
• Viktor B. R. Pedersen and
• Mogens Brøndsted Nielsen

Beilstein J. Org. Chem. 2024, 20, 59–73, doi:10.3762/bjoc.20.8

• expanded by pyrrolo annelation. The optical and redox properties of these compounds, in some cases carbon-rich, were studied by UV–vis absorption spectroscopy and cyclic voltammetry. Synthetically, the work explores IF diones or fluorenone as central building blocks by subjecting the carbonyl groups to a

• a subsequent Glaser–Hay coupling reaction, a RA acceptor unit was introduced to provide a DTF-IF-RA donor–acceptor scaffold with a low-energy charge-transfer absorption and multi-redox behavior. Keywords: alkynes; chromophores; fused-ring systems; heterocycles; redox chemistry; Introduction

• could potentially after deprotonation be reacted with electrophiles as previously established [29] for the parent structure [30] without tert-butyl substituents. UV–vis absorption spectroscopy UV–vis absorption spectra of the known compound 4 [14] and new compounds 9–12 and 15 are depicted in Figure 3

Preparing a liquid crystalline dispersion of carbon nanotubes with high aspect ratio

• Keiko Kojima,
• Nodoka Kosugi,
• Hirokuni Jintoku,
• Kazufumi Kobashi and
• Toshiya Okazaki

Beilstein J. Org. Chem. 2024, 20, 52–58, doi:10.3762/bjoc.20.7

• dispersion. The polarizing optical microscopy (POM) images exhibited alignment of the DWCNTs along the shear direction (Figure 4a,b). To estimate the order parameter, the polarized optical absorption measurement was conducted at different sample angles ranging from 0° to 90° at intervals of 10° (Figure 4c

• ). The sample rotation led to gradual changes in absorption intensities, and the average order parameter was calculated to be ≈0.23 from the spectra of 0° (A∥) and 90° (A⟂) using Equation 1 [21][23]. Generally, it is anticipated that rod-shaped particles with larger L/D will produce a highly aligned film

• flowing air (200 mL/min) at a ramping rate of 1 °C/min. The Raman and absorption spectra were obtained from DWCNT thin film on a silicon substrate. The DWCNT thin film was prepared using vacuum filtration. Raman measurements were conducted using a HORIBA T64000 532 nm laser, while far-infrared (FIR

Using the phospha-Michael reaction for making phosphonium phenolate zwitterions

• Matthias R. Steiner,
• Max Schmallegger,
• Larissa Donner,
• Johann A. Hlina,
• Christoph Marschner,
• Judith Baumgartner and
• Christian Slugovc

Beilstein J. Org. Chem. 2024, 20, 41–51, doi:10.3762/bjoc.20.6

• between P1 and C15 is slightly longer (1.824(2) Å in 2a; 1.828(3) in 2f) when compared to the P–CH2 distance of a tetra-n-butylphosphonium cation [45]. UV–vis spectroscopy All phosphonium phenolate compounds exhibit a bright yellow color in solution (see inset in Figure 3). Investigating the absorption

• properties in chloroform solution revealed an absorption feature ranging from about 310 to 420 nm peaking at 360 ± 3 nm (with molar absorption coefficients (ε) between 4000 and 6000 L mol−1 cm−1) for all zwitterions except 2b and 2h (Figure 3 and Supporting Information File 1, Figure S82). Compounds 2b, the

• Michael adduct of acrylamide, and 2h, the Michael adduct of 2-hydroxyethyl acrylate, show blue-shifted absorption maxima of 352 nm and 356 nm, respectively. Upon increasing the solvent polarity by using methanol instead of chloroform, a hypsochromic shift of the absorption maximum occurs (dotted lines in

Facile access to pyridinium-based bent aromatic amphiphiles: nonionic surface modification of nanocarbons in water

• Lorenzo Catti,
• Shinji Aoyama and
• Michito Yoshizawa

Beilstein J. Org. Chem. 2024, 20, 32–40, doi:10.3762/bjoc.20.5

• similar to AA [12][13], indicating self-assembly via the hydrophobic effect and π-stacking interactions (Figure 3a,b). The self-assembly in water was further supported by UV–visible analysis, displaying slight red-shifts of the anthracene absorption bands relative to the spectrum in methanol (Δλmax = +3

• guest-derived absorption bands around 340 nm and 420–650 nm, confirming the solubilization of C60 in water (Figure 4b). Similar host–guest composites were also obtained using PA-CH3, PA-OH, and PA-Im under the same conditions. It is noteworthy that the C60-solubilization efficiency varied depending on

• showed broad, featureless absorption bands, with a characteristic small peak at ≈580 nm for the E22 transition only in the case of the s-CNT host–guest composite (Figure 4f,g) [24]. The concentration of GN in the aqueous solution of (PA-OCH3)n·(GN)m was estimated to be ≈0.03 mg mL−1. Amphiphile PA-OCH3

Cycloaddition reactions of heterocyclic azides with 2-cyanoacetamidines as a new route to C,N-diheteroarylcarbamidines

• Pavel S. Silaichev,
• Tetyana V. Beryozkina,
• Vsevolod V. Melekhin,
• Valeriy O. Filimonov,
• Andrey N. Maslivets,
• Vladimir G. Ilkin,
• Wim Dehaen and
• Vasiliy A. Bakulev

Beilstein J. Org. Chem. 2024, 20, 17–24, doi:10.3762/bjoc.20.3

• (Mo Kα irradiation, graphite monochromator, ω-scans with 1° step at T = 295(2) K). Empirical absorption correction was applied. The structure was solved using the intrinsic phases in ShelXT program [24] and refined by ShelXL [25] using full-matrix least-squared method for non-hydrogen atoms. The H

Aldiminium and 1,2,3-triazolium dithiocarboxylate zwitterions derived from cyclic (alkyl)(amino) and mesoionic carbenes

• Nedra Touj,
• François Mazars,
• Guillermo Zaragoza and
• Lionel Delaude

Beilstein J. Org. Chem. 2023, 19, 1947–1956, doi:10.3762/bjoc.19.145

• observed for C2 when replacing its acidic proton with a CS2 group among all the nucleophilic carbene precursors that we have investigated so far [40][75]. Yet, we do not have an explanation for it. On IR spectroscopy, the most intense absorption in the ATR spectra of compounds 4a–c and 6a–f was always due

• stretching vibration of the S=C–S− group, another strong absorption was clearly visible in the IR spectra of CAAC·CS2 betaines 4a–c. This second most intense band was observed around 1550 cm−1 (Table 2). It probably originated from the asymmetric stretching of the aldiminium group, in line with similar high

• intensity bands previously observed at ca. 1528 and 1477 cm−1, respectively, in the IR spectra of imidazolinium and imidazolium inner salts [40]. Contrastingly, no remarkable absorption was detected in the IR spectra of triazolium derivatives 6a–f for the CNN or NNN motifs. Yet, in all the cases, medium

Beyond n-dopants for organic semiconductors: use of bibenzo[d]imidazoles in UV-promoted dehalogenation reactions of organic halides

• Kan Tang,
• Megan R. Brown,
• Chad Risko,
• Melissa K. Gish,
• Garry Rumbles,
• Phuc H. Pham,
• Oana R. Luca,
• Stephen Barlow and
• Seth R. Marder

Beilstein J. Org. Chem. 2023, 19, 1912–1922, doi:10.3762/bjoc.19.142

• potentials of the halides that can be reduced in this way, quantum-chemical calculations, and steady-state and transient absorption spectroscopy suggest that UV irradiation accelerates the reactions via cleavage of the dimers to the corresponding radical monomers. Keywords: dehalogenation; n-dopant

• in THF are ca. 420 and 43 M−1 cm−1, respectively. Figure 3a and b show the absorption spectra of the two dimeric reductants in THF (see Supporting Information File 1, Figure S6 for data in toluene). (N-DMBI)2 shows a strong absorption feature with a maximum at 304 nm (εmax = 28000 M−1 cm−1) and a

• bibenzoimidazole portion of the molecules to the C6H4NMe2 Y substituents (see Figure 3d and Supporting Information File 1, Figure S11). Most of the above-mentioned substrates exhibit little or no absorption at 365 nm (see Supporting Information File 1, Figure S4 for comparison of spectra of the reductants and BnBr

Biphenylene-containing polycyclic conjugated compounds

• Cagatay Dengiz

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

• ranging between 45% and 60%. The last step of the sequential reactions is the aromatization step and the target POAs 34a–c were obtained in yields between 80–84%. UV–vis investigations conducted on compounds 34a–c revealed absorption bands that align well with acene structures. While 34a and 34b displayed

• nearly identical absorption profiles with a maximum absorption at λmax = 515 nm, the incorporation of donor groups in compound 34c led to a noteworthy bathochromic shift with a maximum absorption at λmax = 534 nm. Additionally, it was reported that all three compounds, 34a–c, demonstrated remarkable

• )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