The high potential of methyl laurate as a recyclable competitor to conventional toxic solvents in [3 + 2] cycloaddition reactions

• Ayhan Yıldırım and
• Mustafa Göker

Beilstein J. Org. Chem. 2025, 21, 2389–2415, doi:10.3762/bjoc.21.184

• predominance of the trans isomer can be attributed to the stabilizing of secondary orbital interactions in the endo transition state, which results in the formation of this product, in contrast to the exo transition state [53][108]. In this case, the most significant factor is the π–π interaction (π–π stacking

Pathway economy in cyclization of 1,n-enynes

• Hezhen Han,
• Wenjie Mao,
• Bin Lin,
• Maosheng Cheng,
• Lu Yang and
• Yongxiang Liu

Beilstein J. Org. Chem. 2025, 21, 2260–2282, doi:10.3762/bjoc.21.173

• acted as nucleophile, the stable imine–gold–aryl cation–π–π interaction precluded rearrangement and promoted the capture of imine to form spiro[indoline-3,3'-pyridine] derivatives 67. The Ph3PAuCl/AgNTf2-catalyzed cyclization of N-propargyl-tethered amide enynes efficiently afforded four distinct

Photoswitches beyond azobenzene: a beginner’s guide

• Michela Marcon,
• Christoph Haag and
• Burkhard König

Beilstein J. Org. Chem. 2025, 21, 1808–1853, doi:10.3762/bjoc.21.143

• , giving better PSSs) and improved the half-lives without interfering too much with the absorption of the E-indigo (Figure 14). Diarylated indigos like 60g showed the presence of the Z-isomer in the dark, possibly due to the stabilisation energy given by the π–π interaction between the aryl rings (Figure

Orthogonal photoswitching of heterobivalent azobenzene glycoclusters: the effect of glycoligand orientation in bacterial adhesion

• Leon M. Friedrich and
• Thisbe K. Lindhorst

Beilstein J. Org. Chem. 2025, 21, 736–748, doi:10.3762/bjoc.21.57

• with FimH (Supporting Information File 1, Figures S19–S21). In addition to the π–π interaction of the CRD-bound mannose-projecting antenna of the EE isomer with Tyr48, the complex is stabilized by hydrogen bonds of the scaffold mannoside to Tyr48 and in case of the glucose moiety to Thr51, Ile52, and

• Arg92, Asn138, and Asn135 in the ZE isomer. Comparison of the EE and the ZZ isomers of the homobivalent glycocluster 6αMan3αMan 2 also shows very different orientations of the second, non CRD-bound antenna. In case of the EE isomer, the π–π interaction of the CRD-complexed glycoazobenzene antenna with

• the EZ isomer of 6βGlc3αMan 1) (Supporting Information File 1, Figures S22–S25). In the EZ and ZE isomers of 2, the second, non CRD-bound antenna interacts with Gln143 on the backside of the FimH CRD and an additional π–π interaction with Phe142 is seen for the EZ isomer. Interestingly, and somewhat

Deep-blue emitting 9,10-bis(perfluorobenzyl)anthracene

• Long K. San,
• Sebastian Balser,
• Brian J. Reeves,
• Tyler T. Clikeman,
• Yu-Sheng Chen,
• Steven H. Strauss and
• Olga V. Boltalina

Beilstein J. Org. Chem. 2025, 21, 515–525, doi:10.3762/bjoc.21.39

• photochemical reaction. Its structure was elucidated by NMR spectroscopy and single crystal X-ray diffractometry. The latter revealed no π–π interaction between neighboring ANTH cores. A combination of high photoluminescence quantum yield (PLQY) of 0.85 for 9,10-ANTH(BnF)2, its significantly improved

The effect of neighbouring group participation and possible long range remote group participation in O-glycosylation

• Rituparna Das and
• Balaram Mukhopadhyay

Beilstein J. Org. Chem. 2025, 21, 369–406, doi:10.3762/bjoc.21.27

• 9-anthracenylmethyl group in the C-2 position which rendered neighbouring group participation effectively via a favourable π–π interaction between the p-orbitals of the stabilised oxonium ion intermediate and the aromatic ring of the protecting group to yield 1,2-trans selective products. Increasing

Recent advances in organocatalytic atroposelective reactions

• Henrich Szabados and
• Radovan Šebesta

Beilstein J. Org. Chem. 2025, 21, 55–121, doi:10.3762/bjoc.21.6

• , previous findings from the literature, and experimental results, a reaction mechanism was proposed [46]. Hydrogen bonding as well as π–π interaction with the catalyst (R)-C22 activates both substrates in the stable intermediate Int-35. This stabilized state ensures the concerted control of

The charge transport properties of dicyanomethylene-functionalised violanthrone derivatives

• Sondos A. J. Almahmoud,
• Joseph Cameron,
• Dylan Wilkinson,
• Michele Cariello,
• Claire Wilson,
• Alan A. Wiles,
• Peter J. Skabara and
• Graeme Cooke

Beilstein J. Org. Chem. 2024, 20, 2921–2930, doi:10.3762/bjoc.20.244

• contributed to a lower intermolecular π–π interaction and, therefore, lower μh (3.62 × 10−6 cm2 V−1 s−1) compared to the previously reported 2a (4.93 × 10−5 cm2 V−1 s−1) [30]. Conclusion Violanthrone derivatives represent a promising group of semiconductor materials for organic electronics. It has been shown

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

• safer control of Vm. Keywords: liposome; π–π interaction; reactive oxygen species; superoxide radical anion; Introduction The [60]fullerene (C60) is known as an excellent electron acceptor [1][2] and is commonly used in organic solar cell applications [3]. Taking advantage of the fact that C60 can be

Competing electrophilic substitution and oxidative polymerization of arylamines with selenium dioxide

• Vishnu Selladurai and
• Selvakumar Karuthapandi

Beilstein J. Org. Chem. 2024, 20, 1221–1235, doi:10.3762/bjoc.20.105

• structure, it self-organized through π–π interaction between the oxamide motif and the aryl π-framework. Further, the CH…O=C interaction facilitated the formation of ladder-like packing in the solid state (Figure S36, Supporting Information File 1). The molecular structure of oxamide 13 is shown in Figure 3

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

• derivatives are among the most investigated due to their easy functionalization, high chemical and thermal stability, strong photoluminescence, and n-type semiconductor character. They tend to adopt columnar organization due to the strong π–π interaction of the rigid cores, providing a path for the efficient

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

• , resulting in an efficiency of 18% and marking a significant advancement in OSC research [27]. Zhou and co-workers synthesized Y6-type NFA acceptors, Qx12 and Qx13, by substituting Y6’s benzothiadiazole ring with a Qx moiety. Qx13 exhibited a stronger π–π interaction compared to Qx12, which facilitated

Aromatic C–H bond functionalization through organocatalyzed asymmetric intermolecular aza-Friedel–Crafts reaction: a recent update

• Anup Biswas

Beilstein J. Org. Chem. 2023, 19, 956–981, doi:10.3762/bjoc.19.72

• bond formed between the imine nitrogen of 49 and the catalyst’s OH group (see transition state 84). These dual H-bonding interactions were assisted by a π–π interaction between the arene rings of both the electrophile and nucleophile that helped in the formation of a stereodefined transition state. The

Asymmetric organocatalytic Michael addition of cyclopentane-1,2-dione to alkylidene oxindole

• Estelle Silm,
• Ivar Järving and
• Tõnis Kanger

Beilstein J. Org. Chem. 2022, 18, 167–173, doi:10.3762/bjoc.18.18

• ). When instead of a benzylidene-containing substrate an alkylidene with an extra ester moiety was used, the enantioselectivity was lost and the product 3i was obtained as a racemic mixture. Either additional coordination with the catalyst or a lack of π–π-interaction may have been responsible for that

Recent advances in the asymmetric phosphoric acid-catalyzed synthesis of axially chiral compounds

• Alemayehu Gashaw Woldegiorgis and
• Xufeng Lin

Beilstein J. Org. Chem. 2021, 17, 2729–2764, doi:10.3762/bjoc.17.185

• -naphthylamine and azodicarboxylate through a dual hydrogen bond activation mode and a π–π interaction strategy (Scheme 31) [2]. Diarylamines and related scaffolds are among the most common potentially atropisomeric chemotypes in medicinal chemistry. For example, the drugs binimetinib and bosutinib contain

In-depth characterization of self-healing polymers based on π–π interactions

• Josefine Meurer,
• Julian Hniopek,
• Johannes Ahner,
• Michael Schmitt,
• Jürgen Popp,
• Stefan Zechel,
• Kalina Peneva and
• Martin D. Hager

Beilstein J. Org. Chem. 2021, 17, 2496–2504, doi:10.3762/bjoc.17.166

• second phase transition of the PEG moieties observed in the DSC. Nevertheless, at 150 °C, P2 also shows the clear broadening of bands, which is consistent with the very similar positions for the perylene π–π interaction signal in the DSC. All these findings clearly support that at increased temperatures

• , which correlates to the changes of the molecular structure. Furthermore, the scratch healing was analyzed in detail showing that only one of the two polymers studied, polymer P1 is able to heal scratches in a sufficient manner at temperature higher than the activation of the π–π interaction. In contrast

Multiswitchable photoacid–hydroxyflavylium–polyelectrolyte nano-assemblies

• Alexander Zika and
• Franziska Gröhn

Beilstein J. Org. Chem. 2021, 17, 166–185, doi:10.3762/bjoc.17.17

• molecular recognition processes have been established based on different non-covalent interactions such as hydrogen bonding [9][10][11][12], π–π interaction [13][14][15][16][17], hydrophobic effects, and amphiphilicity [18][19][20][21]. It has been highly desirable to establish concepts that could be

Synthesis, crystal structures and properties of carbazole-based [6]helicenes fused with an azine ring

• Daria I. Tonkoglazova,
• Anna V. Gulevskaya,
• Konstantin A. Chistyakov and
• Olga I. Askalepova

Beilstein J. Org. Chem. 2021, 17, 11–21, doi:10.3762/bjoc.17.2

• in its length from the standard single C(sp2)–C(sp2) bond (ca. 1.48 Å). The X-ray analysis of quinoxaline-fused [6]helicene 10a revealed the presence of the face-to-face π–π interaction between the helicene aggregates. The racemic aggregation was composed by (P)- and (M)-enantiomers on the manner of

Thermodynamic and electrochemical study of tailor-made crown ethers for redox-switchable (pseudo)rotaxanes

• Henrik Hupatz,
• Marius Gaedke,
• Hendrik V. Schröder,
• Julia Beerhues,
• Arto Valkonen,
• Fabian Klautzsch,
• Sebastian Müller,
• Felix Witte,
• Kari Rissanen,
• Biprajit Sarkar and
• Christoph A. Schalley

Beilstein J. Org. Chem. 2020, 16, 2576–2588, doi:10.3762/bjoc.16.209

• non-folded conformation. The torsional angle between the central phenyl ring and the NDI is 84.2° in order to avoid strain between the protons of the resorcinol and the carbonyl groups of the NDI. Consequently, an intramolecular π–π-interaction with the naphthalene on the other side of the macrocycle

Highly selective Diels–Alder and Heck arylation reactions in a divergent synthesis of isoindolo- and pyrrolo-fused polycyclic indoles from 2-formylpyrrole

• Carlos H. Escalante,
• Eder I. Martínez-Mora,
• Carlos Espinoza-Hicks,
• Alejandro A. Camacho-Dávila,
• Fernando R. Ramos-Morales,
• Francisco Delgado and
• Joaquín Tamariz

Beilstein J. Org. Chem. 2020, 16, 1320–1334, doi:10.3762/bjoc.16.113

• ) [58][59][65]. Regarding the addition of diene 8c with the N-methylmaleimide (7b), a π···π interaction is discarded. Nevertheless, the endo adduct 9g was obtained as the major diastereoisomer (Table 2, entry 7). The calculated geometry at the endo TS reveals a plausible Cmethyl–H···π interaction, based

Synthesis, antiinflammatory activity, and molecular docking studies of bisphosphonic esters as potential MMP-8 and MMP-9 inhibitors

• Abimelek Cortes-Pacheco,
• María Adelina Jiménez-Arellanes,
• Francisco José Palacios-Can,
• José Antonio Valcarcel-Gamiño,
• Rodrigo Said Razo-Hernández,
• María del Carmen Juárez-Vázquez,
• Adolfo López-Torres and
• Oscar Abelardo Ramírez-Marroquín

Beilstein J. Org. Chem. 2020, 16, 1277–1287, doi:10.3762/bjoc.16.108

• was occupying the entire pocket was compound 6 due to the formation of four hydrogen bonds and a favourable π–π interaction between the methoxybenzyl group and His197. Only for 3 and 4, one of the oxygen atoms of the phosphonate units was the most contributing atom to the interaction energy. However

Recent applications of porphyrins as photocatalysts in organic synthesis: batch and continuous flow approaches

• Rodrigo Costa e Silva,
• Luely Oliveira da Silva,
• Aloisio de Andrade Bartolomeu,
• Timothy John Brocksom and
• Kleber Thiago de Oliveira

Beilstein J. Org. Chem. 2020, 16, 917–955, doi:10.3762/bjoc.16.83

• (1.87 nm), acts as a size-selective photocatalyst. Furthermore, the photocatalytic activity of 2D-COF is lower due to the π–π interaction between framework layers. Nitrogen oxidation: Amines are well-known as very efficient physical and chemical quenchers for singlet oxygen [67][100][101]. A myriad of

Design and synthesis of diazine-based panobinostat analogues for HDAC8 inhibition

• Sivaraman Balasubramaniam,
• Sajith Vijayan,
• Liam V. Goldman,
• Xavier A. May,
• Kyra Dodson,
• Sweta Adhikari,
• Fatima Rivas,
• Davita L. Watkins and
• Shana V. Stoddard

Beilstein J. Org. Chem. 2020, 16, 628–637, doi:10.3762/bjoc.16.59

• indole ring of TOI4 was also contorted upward, forming a T-shaped π–π interaction with Phe-207 while both the indole rings of TOI1 and TOI2 were shown to be flipped downward forming a T-shaped π–π interaction with Phe-208. TOI4 is the only diazine compound having two nitrogens directly next to each other

• -rev is tilted downward forming a T-shaped π–π interaction with Phe-208. In review of the computational results, the inclusion of the nitrogen atoms in the core ring structure of panobinostat produced compounds with predicted binding affinities similar to panobinostat. Thus, aiming to develop improved

Efficient synthesis of 3,6,13,16-tetrasubstituted-tetrabenzo[a,d,j,m]coronenes by selective C–H/C–O arylations of anthraquinone derivatives

• Seiya Terai,
• Yuki Sato,
• Takuya Kochi and
• Fumitoshi Kakiuchi

Beilstein J. Org. Chem. 2020, 16, 544–550, doi:10.3762/bjoc.16.51

• ,j,m]coronene 7aa was also examined (Figure 2), as Wu and co-workers have studied the self-assembling property of the tetrabenzo[a,d,j,m]coronene derivative possessing n-octyl groups at the 2, 7, 12, and 17-positions by 1H NMR spectroscopy and suggested its intermolecular π–π interaction in solution

• 5 × 10−4 M at rt also led to a downfield shift and sharpening of the signals. These observations suggest that 7aa assembles by intermolecular π–π interaction in CDCl3 as was seen by Wu and co-workers for their compound possessing substituents at different positions. Conclusion The synthesis of a new

Six-fold C–H borylation of hexa-peri-hexabenzocoronene

• Mai Nagase,
• Kenta Kato,
• Akiko Yagi,
• Yasutomo Segawa and
• Kenichiro Itami

Beilstein J. Org. Chem. 2020, 16, 391–397, doi:10.3762/bjoc.16.37

• bonds of HBC (Figure 3a). An equivalent amount of pentane for 1 was co-crystallized. As illustrated in Figure 3b and 3c, 1 is slightly distorted to have S6 symmetry, and no π–π interaction is observed in the packing mode reflecting the steric hindrance of boryl groups. This result corresponds with the