Interaction of a pyrene derivative with cationic [60]fullerene in phospholipid membranes and its effects on photodynamic actions

• Hayato Takagi,
• Çetin Çelik,
• Ryosuke Fukuda,
• Qi Guo,
• Tomohiro Higashino,
• Hiroshi Imahori,
• Yoko Yamakoshi and
• Tatsuya Murakami

Beilstein J. Org. Chem. 2024, 20, 2732–2738, doi:10.3762/bjoc.20.231

• generation of ROS by catC60 in the absence or presence of PyBA. As spin trapping reagents for the singlet oxygen (1O2), hydroxyl radical (•OH) and superoxide radical anion (O2•–); 2,2,6,6,-tetramethyl-4-piperidone (4-oxo-TEMP), 3,4-dihydro-2,3-dimethyl-2H-pyrrole 1-oxide (DMPO), and 5-(diethoxyphosphoryl)-5

• µM, PyBA 67 µM, and 4-oxo-TEMP 100 μM, in PBS(–) under irradiation for 30 min by blue LED lamp. (b) X-band ESR spectra of 3,4-dihydro-2,3-dimethyl-2H-pyrrole 1-oxide (DMPO) adduct with •OH generated by catC60 under irradiation by a blue LED. Experimental conditions: (i) catC60 5 µM, β-nicotinamide

Deuterated reagents in multicomponent reactions to afford deuterium-labeled products

• Kevin Schofield,
• Shayna Maddern,
• Yueteng Zhang,
• Grace E. Mastin,
• Rachel Knight,
• Wei Wang,
• James Galligan and
• Christopher Hulme

Beilstein J. Org. Chem. 2024, 20, 2270–2279, doi:10.3762/bjoc.20.195

• aldehyde [10]. Latterly, Yamamoto utilized a 90% deuterated [D2]-isocyanide in a copper catalyzed [3 + 2] cycloaddition to afford a 60% deuterated [D2]-pyrrole [11]. The utility of the Leuckart–Wallach reaction towards the generation of isocyanides was first explored by Dömling [12], yet the use of such

Novel truxene-based dipyrromethanes (DPMs): synthesis, spectroscopic characterization and photophysical properties

• Shakeel Alvi and
• Rashid Ali

Beilstein J. Org. Chem. 2024, 20, 2163–2170, doi:10.3762/bjoc.20.186

• for diverse applications in future studies. Keywords: condensation; co-timerization; dipyrromethane; Friedel–Crafts acylation; heterocycles; pyrrole; truxene; Introduction The scaffold of truxene (10,15‐dihydro‐5H‐diindeno[1,2‐a;1′,2′‐c]fluorene) and its congeners comprises three fluorene subunits

• truxenes with freshly distilled pyrrole using trifluoroacetic acid (TFA) as an acidic catalyst afforded the anticipated DPM-appended truxene derivatives (14, 16 and 18) in good yields (60–80%). All the newly prepared DPM-linked truxene-hybrid molecules as well as the intermediate acetylated truxene

• General: All the reagents/solvents were purchased from commercial suppliers (Sigma-Aldrich, Alfa Aesar, TCI, GLR innovation, Avera, Spectrochem and Across), and used without further purification. Solvents were dried according to standard reported procedures. Pyrrole was used after a fresh distillation

Allostreptopyrroles A–E, β-alkylpyrrole derivatives from an actinomycete Allostreptomyces sp. RD068384

• Marwa Elsbaey,
• Naoya Oku,
• Mohamed S. A. Abdel-Mottaleb and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2024, 20, 1981–1987, doi:10.3762/bjoc.20.174

• , copolymerized β-alkylpyrroles are among the most investigated organic materials for their enhanced physical and electrochemical properties [4][5]. Accordingly, chemists have focused on developing selective synthetic strategies for the construction of β-alkylpyrroles [1]. While the pyrrole nucleus is featured in

• many marine natural products [6][7], pyrroles substituted with long hydrocarbon chains (pyrrole lipids) are seldomly isolated, and their presence is limited to certain marine organisms [8]. A series of 3-alkylpyrrole-2-carbaldehydes/carboxylic acid/methylcarboxylate was reported from the marine sponge

• metabolites, and most of them are pyrroloterpenes from Streptomyces (Figure 1 and Figure S54 in Supporting Information File 1). Examples include pyrrolostatin [12] and its congener geranylpyrrol A [13], bearing a carboxylic group at the C2 and a geranyl group at the C4 position of the pyrrole ring, and their

Radical reactivity of antiaromatic Ni(II) norcorroles with azo radical initiators

• Siham Asyiqin Shafie,
• Ryo Nozawa,
• Hideaki Takano and
• Hiroshi Shinokubo

Beilstein J. Org. Chem. 2024, 20, 1967–1972, doi:10.3762/bjoc.20.172

• through denitrogenation of AIBN, is closer to the HOMO level of Ni(II) norcorrole 1 (−4.68 eV) rather than its LUMO (−3.16 eV). This result explains the selective addition of the electrophilic isobutyronitrile radical to the distal α-position of the pyrrole unit. The calculated molecular orbital

• coefficient of the HOMO indicates that two α-carbon atoms of the pyrrole subunits are the most reactive positions for electrophilic species. In addition, the distal α-carbon atom relative to the meso-position could be more reactive than the proximal α-carbon atom due to the steric hindrance of bulky mesityl

• groups. Consequently, the isobutyronitrile radical predominantly attacks the distal α-carbon atom relative to the meso-position to afford the corresponding radical intermediate I. The calculated spin density of radical I revealed a substantial radical character at the α-position of the pyrrole skeleton

A new platform for the synthesis of diketopyrrolopyrrole derivatives via nucleophilic aromatic substitution reactions

• Vitor A. S. Almodovar and
• Augusto C. Tomé

Beilstein J. Org. Chem. 2024, 20, 1933–1939, doi:10.3762/bjoc.20.169

• Micromass Q-TOF-2TM mass spectrometer and CHCl3 as the solvent. The NMR, absorption and emission spectra of the new compounds are shown in Supporting Information File 1. Synthesis 3,6-Bis(4-chlorophenyl)-2,5-bis(pentafluorobenzyl)-2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione (2) A suspension of DPP 1 (1 g

2-Heteroarylethylamines in medicinal chemistry: a review of 2-phenethylamine satellite chemical space

• Carlos Nieto,
• Alejandro Manchado,
• Ángel García-González,
• David Díez and
• Narciso M. Garrido

Beilstein J. Org. Chem. 2024, 20, 1880–1893, doi:10.3762/bjoc.20.163

• 2-aminoethylpyrrole (Scheme 7) hits were elaborated and tested in a stopped-flow CO2 hydrase assay. Comparing this pyrrole family with original histamine inferred a decrease in selectivity towards the hCA VII isoform, while activity was not affected significantly. Tryptamine derivatives, i.e

The Groebke–Blackburn–Bienaymé reaction in its maturity: innovation and improvements since its 21st birthday (2019–2023)

• Cristina Martini,
• Muhammad Idham Darussalam Mardjan and
• Andrea Basso

Beilstein J. Org. Chem. 2024, 20, 1839–1879, doi:10.3762/bjoc.20.162

• intramolecular nucleophilic addition of the secondary amines to the internal alkyne was expected to occur, forming a new pyrrole ring in 93 through a 5-endo-dig cyclization. Unexpectedly, they observed the generation of 95 with a new pyridine ring. The authors proposed that the benzylamine unit of 92 was

Hetero-polycyclic aromatic systems: A data-driven investigation of structure–property relationships

• Sabyasachi Chakraborty,
• Eduardo Mayo Yanes and
• Renana Gershoni-Poranne

Beilstein J. Org. Chem. 2024, 20, 1817–1830, doi:10.3762/bjoc.20.160

• in size, composition, and aromatic character: benzene, pyridine, pyrazine, borinine, 1,4-diborinine, 1,4-dihydro-1,4-diborinine, borole, pyrrole, furan, thiophene, and cyclobutadiene (Figure 1A). These building blocks encompass 6-, 5-, and 4-membered rings with aromatic and antiaromatic character

• pronounced for pyrazine than pyridine). Conversely, the five-membered ring (pyrrole) shifts it to the right and upwards, maintaining a similar HOMO range to COMPAS-1, but extending into much higher LUMO values. The behavior of the various N-containing rings is well documented in the literature [17][44][45

• findings, however they also reveal additional information. Primarily, these plots demonstrate the cumulative effect of incorporating multiple rings. Furthermore, the slopes of the lines indicate the strength of the effects – e.g., it can be seen clearly that pyrrole has a much stronger effect on the HOMO

Ugi bisamides based on pyrrolyl-β-chlorovinylaldehyde and their unusual transformations

• Alexander V. Tsygankov,
• Vladyslav O. Vereshchak,
• Tetiana O. Savluk,
• Serhiy M. Desenko,
• Valeriia V. Ananieva,
• Oleksandr V. Buravov,
• Yana I. Sakhno,
• Svitlana V. Shishkina and
• Valentyn A. Chebanov

Beilstein J. Org. Chem. 2024, 20, 1773–1784, doi:10.3762/bjoc.20.156

• University, Svobody sq., 4, 61022, Kharkiv, Ukraine 10.3762/bjoc.20.156 Abstract By one-pot four- and three-component Ugi reactions involving convertible isocyanides and unexplored pyrrole-containing β-chlorovinylaldehyde, a small library of 20 bisamides with unusual behavior in post-Ugi transformations was

• ; post-Ugi transformation; pyrrole derivative; Ugi reaction; Introduction One of the keys to the development of mankind is the constant search for new substances and advanced materials. Today, we have powerful tools at our disposal that allow us to create entire libraries of structurally complex organic

• , azomethines based on aromatic amines and substituted pyrrolecarbaldehyde [40] or pyrrolyl-β-chlorovinylaldehyde [39], contain several frequently encountered motifs in drugs and drug candidates – a pyrrole heterocycle and an azomethine C=N fragment (Figure 1) – and exhibit some biological activity. Thus, Ugi

Harnessing unprotected deactivated amines and arylglyoxals in the Ugi reaction for the synthesis of fused complex nitrogen heterocycles

• Javier Gómez-Ayuso,
• Pablo Pertejo,
• Tomás Hermosilla,
• Israel Carreira-Barral,
• Roberto Quesada and
• María García-Valverde

Beilstein J. Org. Chem. 2024, 20, 1758–1766, doi:10.3762/bjoc.20.154

• acid, indole-2-carboxylic acid, pyrrole-2-carboxylic acid or N-phenylglycine has allowed the use of these compounds in the Ugi reaction without triggering competitive reactions. The additional functional group present in the resulting Ugi adduct can be leveraged in different post-condensation

• strategy with aromatic amines [24], pyrrole-2-carboxylic acid and N-phenylglycine, and carried out their reactions with arylglyoxals, alkylamines and isocyanides (Scheme 5). As we expected, the cyclization product 9 was observed, although the complete cyclization of the Ugi adduct, found as the enol

• tautomer, needed the addition of hydrochloric acid (1 equiv) in the case of the tert-butylamine derivatives. However, the nature of the cyclization product depended on the carboxylic acid employed in the Ugi reaction. Thus, the indole and pyrrole derivatives yielded the corresponding hemiaminal 9 as a

Polymer degrading marine Microbulbifer bacteria: an un(der)utilized source of chemical and biocatalytic novelty

• Weimao Zhong and
• Vinayak Agarwal

Beilstein J. Org. Chem. 2024, 20, 1635–1651, doi:10.3762/bjoc.20.146

• together with genes encoding the production of polybrominated pyrroles [138][139][140]. The Microbulbifer BGCs lack genes for brominated pyrrole biosynthesis and polybrominated pyrroles have not been reported to be produced by Microbulbifer bacteria. Future studies looking at the evolutionary relationship

Synthetic applications of the Cannizzaro reaction

• Bhaskar Chatterjee,
• Dhananjoy Mondal and
• Smritilekha Bera

Beilstein J. Org. Chem. 2024, 20, 1376–1395, doi:10.3762/bjoc.20.120

• an aldol transformation to the final product. Bruckner and coworkers synthesized pyrrole-modified porphyrin ring systems from secochlorin bisaldehydes, representing an interesting application of the intramolecular Cannizzaro reaction. Subjecting the bisaldehyde 92 to basic conditions using Et4NOH

Diameter-selective extraction of single-walled carbon nanotubes by interlocking with Cu-tethered square nanobrackets

• Guoqing Cheng and
• Naoki Komatsu

Beilstein J. Org. Chem. 2024, 20, 1298–1307, doi:10.3762/bjoc.20.113

• @(12,2)-SWNT complexes. Chemical structures of Cu-tethered tetragonal nanobrackets 1a and 1b. Synthesis of nanobracket 4. Reaction conditions: i) XPhos Pd G2, XPhos, B2(OH)4, KOAc, EtOH, 80 °C, 2 h; ii) Br-Ar-Br, K2CO3, tetrahydrofuran (THF)/toluene, 80 °C, 16 h; iii) trifluoroacetic acid (TFA), pyrrole

The Ugi4CR as effective tool to access promising anticancer isatin-based α-acetamide carboxamide oxindole hybrids

• Carolina S. Marques,
• Aday González-Bakker and
• José M. Padrón

Beilstein J. Org. Chem. 2024, 20, 1213–1220, doi:10.3762/bjoc.20.104

• alkene 2j carboxylic acids were used successfully in this MCR, demonstrating a great reaction scope (Scheme 2 and Figure 2). Remarkably, the best yields were obtained when heterocyclic carboxylic acid components like 1H-pyrrole-3-carboxylic acid (2n), 2-furoic acid (2o) and 5-nitrofuran-2-carboxylic acid

• , 72, 74 and 84% yield, respectively. An exception was noticed for N-heterocycle units (pyridine and 1H-pyrrole) substituted in the same position, since compounds 8g, 8l and 8i were obtained in 56, 51 and 36% yield, respectively. The 1,2,3-triazole hybrid isatin compound 8n was obtained in 56% yield

Manganese-catalyzed C–C and C–N bond formation with alcohols via borrowing hydrogen or hydrogen auto-transfer

• Mohd Farhan Ansari,
• Atul Kumar Maurya,
• Abhishek Kumar and
• Saravanakumar Elangovan

Beilstein J. Org. Chem. 2024, 20, 1111–1166, doi:10.3762/bjoc.20.98

• pyrrole synthesis under the same reaction conditions. In 2019, Rueping, El-Sepelgy and co-workers achieved the sustainable multicomponent synthesis of pyrroles from readily available substrates catalyzed by manganese-pincer complex Mn12 [96]. The use of 2 mol % of Mn12 in combination with a catalytic

Auxiliary strategy for the general and practical synthesis of diaryliodonium(III) salts with diverse organocarboxylate counterions

• Naoki Miyamoto,
• Daichi Koseki,
• Kohei Sumida,
• Elghareeb E. Elboray,
• Naoko Takenaga,
• Ravi Kumar and
• Toshifumi Dohi

Beilstein J. Org. Chem. 2024, 20, 1020–1028, doi:10.3762/bjoc.20.90

• conditions and the use of an equimolar amount of the metal salt (Scheme 2A). Despite the expected advantage, direct synthesis of these diaryliodonium(III) carboxylates are scarce, and these compounds were synthesized by reacting (diacetoxyiodo)benzene and N-functionalized pyrrole in 2,2,2-trifluoroethanol

A Diels–Alder probe for discovery of natural products containing furan moieties

• Alyssa S. Eggly,
• Namuunzul Otgontseren,
• Carson B. Roberts,
• Amir Y. Alwali,
• Haylie E. Hennigan and
• Elizabeth I. Parkinson

Beilstein J. Org. Chem. 2024, 20, 1001–1010, doi:10.3762/bjoc.20.88

• the carboxylic acid in the three position, the phenyl group is most likely too electron-donating, as well as potentially being too sterically bulky. Finally, pyrrole 21 was tested and ultimately resulted in an inconclusive amount of conversion. Compound 21 does not ionize well on our LC–MS and thus we

Carbonylative synthesis and functionalization of indoles

• Alex De Salvo,
• Raffaella Mancuso and
• Xiao-Feng Wu

Beilstein J. Org. Chem. 2024, 20, 973–1000, doi:10.3762/bjoc.20.87

• recent achievements on the synthesis and functionalization of indole derivatives via carbonylative approaches. Keywords: carbonylation; functionalization; indole; metal catalyst; organometallic chemistry; Introduction Indole is a heterocyclic compound consisting of a benzene ring fused with a pyrrole

Enantioselective synthesis of β-aryl-γ-lactam derivatives via Heck–Matsuda desymmetrization of N-protected 2,5-dihydro-1H-pyrroles

• Arnaldo G. de Oliveira Jr.,
• Martí F. Wang,
• Rafaela C. Carmona,
• Danilo M. Lustosa,
• Sergei A. Gorbatov and
• Carlos R. D. Correia

Beilstein J. Org. Chem. 2024, 20, 940–949, doi:10.3762/bjoc.20.84

• neutral (4ab, 34% yield) and electron-withdrawing (4ac, 27% yield) ones, but no significant changes in the enantiomeric ratio were observed (Scheme 3). Despite the formation of the hemiaminal ether as the major product, the formation of a minor N-Boc pyrrole was also observed as a side-product. To

• circumvent this side reaction, we envisioned that a more electron-withdrawing protecting group could reduce the tendency of the starting olefin to oxidation. Therefore, the N-tosylated 2,5-dihydro-1H-pyrrole 1b was evaluated under the same reaction conditions with the same three aryldiazonium salts used

• -nitrophenyl)sulfonyl (2-Ns) as alternative protecting groups of 2,5-dihydro-1H-pyrrole (Scheme 5). Although the results with the 2-Ns protecting group were somewhat disappointing, the results with 4-Ns group were more promising, even with a welcome increase in the enantiomeric ratio in some cases (4dd and 4de

SOMOphilic alkyne vs radical-polar crossover approaches: The full story of the azido-alkynylation of alkenes

• Julien Borrel and
• Jerome Waser

Beilstein J. Org. Chem. 2024, 20, 701–713, doi:10.3762/bjoc.20.64

• homopropargylic azide was formed using pyrrole 1e it could not be isolated due to its instability. No conversion was observed when the transformation was attempted directly on the indole scaffold 1f. Only a small amount of product was formed using styrene 1g bearing an extra α-phenyl substituent. A slightly

Chemical and biosynthetic potential of Penicillium shentong XL-F41

• Ran Zou,
• Xin Li,
• Xiaochen Chen,
• Yue-Wei Guo and
• Baofu Xu

Beilstein J. Org. Chem. 2024, 20, 597–606, doi:10.3762/bjoc.20.52

• transformation of the five-membered pyrrole ring in compound 2 to the six-membered ring in compound 1 is particularly intriguing. For this transformation, three hypotheses are considered. One suggests that the methyl modification at the oxygen atom of the succinimide ring occurs first, which is then followed by

• from the known brocaeloid D by the addition of a methyl group, and there is a change in the relative stereochemistry at C2 and C3. In addition, the conversion of the five-membered pyrrole ring in compound 2 to the six-membered piperidine ring in compound 1 is intriguing. Although there have been many

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

• -responsive switchable tweezers are based on an H-bonding motif that can establish recognition interactions with the anionic species. One of the first examples was developed by Sessler, Jeppesen, and co-workers with a calix[4]pyrrole switching unit [68]. Calix[4]pyrrole tweezers 33 are functionalized by four

• tetrathiafulvalene (TTF) arms, adopting a 1,3-alternate conformation by default with two cavities for binding electron-poor guests between the TTFs (Figure 18). The authors demonstrated complexation with 1,3,5-trinitrobenzene and other electron-poor guests such as TCNQ. The N–H protons of the pyrrole subunits can

• -conformation calix[4]pyrrole and the electron-donating nature of TTFs allow the complexation of electron-poor C60 guests [71]. A 2:1 complexation of C60 by TTF-functionalized calix[4]pyrrole 33 was observed for the Cl− bound cone conformation with each calix[4]pyrrole entrapping C60 on one side. The complex

Mono or double Pd-catalyzed C–H bond functionalization for the annulative π-extension of 1,8-dibromonaphthalene: a one pot access to fluoranthene derivatives

• Nahed Ketata,
• Linhao Liu,
• Ridha Ben Salem and
• Henri Doucet

Beilstein J. Org. Chem. 2024, 20, 427–435, doi:10.3762/bjoc.20.37

• substituted at positions 2 and 5 with 1,8-dibromonaphthalene using 5 mol % PdCl(C3H5)(dppb) catalyst with KOPiv as the base in DMA (Scheme 3). From 2,5-dimethylthiophene or 1,2,5-trimethylpyrrole, the desired acenaphtho[1,2-c]thiophene 16 and acenaphtho[1,2-c]pyrrole and 17 were obtained in 60% and 56% yield

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

• unambiguously established based on COSY, HSQC, and HMBC NMR-spectroscopic data. Further, the 15N NMR spectrum of 5a confirmed the typical pyrrole-like character of the N(12) atom as well as the pyridine-like character of the N(7) and N(14) atoms (Figure S31, Supporting Information File 1) [21][22]. The