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

• intermolecular steric interaction [53]. The weak AIE characteristic of TPECNz in the aggregate state could be attributed to the competition between the twisted ICT and AIE properties in the molecule [57][58]. The thermal properties of TPECNz were studied by thermogravimetric analysis (TGA) and differential

Tying a knot between crown ethers and porphyrins

• Maksym Matviyishyn and
• Bartosz Szyszko

Beilstein J. Org. Chem. 2023, 19, 1630–1650, doi:10.3762/bjoc.19.120

• complexes, the fragment originating from the porphyrinoid could form hydrogen bonds with a carboxyl group, while the crown ether cavity would allow interaction with the protonated amine group of an amino acid molecule. The choice of macrocycle size could enable the recognition of different biomolecules

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

• from 25 to 55%. The remaining β-CD derivatives showed a lower effect at 25 and 50% CHOL. Discussion The CD–membrane interaction was broadly studied in the past few decades. The ability of CDs to induce membrane permeabilization was also proved in numerous reports. This effect was dose dependent which

• increase in the fluidity of DPPC liposomes through the interaction of HP-β-CD with the polar head group region and the acyl chains of DPPC [24]. Although the complex between HP-β-CD and CHOL has been previously characterized [25], this complex seems to be unstable. Thus, a better interaction would occur

• where γ-CD always exhibited low vesicle leakage [29]. Actually, γ-CD was found to be less lipid specific than the remaining native CDs (α-CD and β-CD) [8], which implies that the interaction of γ-CD with DPPC would be not favorable. Considering its large cavity in comparison to α and β-CD, γ-CD is not

Complexes of resorcin[4]arene with secondary amines: synthesis, solvent influence on “in-out” structure, and theoretical calculations of non-covalent interactions

• Waldemar Iwanek

Beilstein J. Org. Chem. 2023, 19, 1525–1536, doi:10.3762/bjoc.19.109

• also found that the stoichiometry of the formed complexes depends on the size of the amine molecule. The automated interaction sites screening (aISS) made it possible to generate molecular ensembles of complexes. The geometry of the ensembles was first optimized with the r2scan-3c functional and

• of non-covalent interactions within various types of supramolecular complexes [17]. One such method is HFLD [18], which can be considered a dispersion-corrected HF approach where the dispersion interaction between fragments is added at the DLPNO-CC level. The HFLD method demonstrates comparable

• performance to HF in terms of total interaction energies while maintaining the accuracy of DLPNO CCSD(T) [19]. This method proves very accurate in quantifying non-covalent interactions, such as those found in hydrogen-bonded systems, among others. Despite the relatively small cavity in the structure of

Unraveling the role of prenyl side-chain interactions in stabilizing the secondary carbocation in the biosynthesis of variexenol B

• Moe Nakano,
• Rintaro Gemma and
• Hajime Sato

Beilstein J. Org. Chem. 2023, 19, 1503–1510, doi:10.3762/bjoc.19.107

• possibility of through-space interactions with prenyl side chains using DFT calculations. Our calculations show that (i) the unstable secondary carbocation is stabilized by the cation–π interaction from prenyl side chains, thereby lowering the activation energy, (ii) the four-membered ring formation is

• completed through bridging from the exomethylene group, and (iii) the annulation from the exomethylene group proceeds in a barrier-free manner. Keywords: biosynthesis; carbocation; cation–π interaction; DFT; terpene; Introduction Terpene/terpenoids are most abundant natural products in nature, more than

• as the C–H–π interaction between the carbocation intermediate and the Phe residue of terpene cyclase in the biosynthesis of sesterfisherol [21], and the intricated rearrangement reaction mechanism promoted by the equilibrium state of the homoallyl cation and the cyclopropylcarbinyl cation in the

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

• sulfur atom to Fe3+ to generate Fe2+ and radical cation I. Subsequent cleavage of the N–S bond led to cation II and radical III. Interaction of III with Fe2+ regenerated the Fe3+ species and IV. At the same time, electrophilic addition of II to alkene 9 yielded intermediate V, which was subjected to the

• activated the N–S bond in II, which reacted with I to obtain IV, followed by C–S reductive elimination to give the thiolated product 30 or 31. On the other hand, the interaction of I with Cu(OAc)2 activated the N–S bond in III to afford IV, which was subjected to C–N reductive elimination to deliver the

• dihydropyrazoles 54 as products (Scheme 22) [59]. A credible pathway for the production of isoxazole 53 is illustrated in Scheme 23. The interaction of 1 with BF3·Et2O resulted in intermediate I that is in balance with I’. Cleavage of the N–S bond of I afforded cationic species PhS+ II, which activated the double

Functions of enzyme domains in 2-methylisoborneol biosynthesis and enzymatic synthesis of non-natural analogs

• Binbin Gu,
• Lin-Fu Liang and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2023, 19, 1452–1459, doi:10.3762/bjoc.19.104

• needs a covalent bond between the two domains A and B, as indicated by a similar precipitation of domain B alone and domain B in the presence of domain A. In these experiments, the N-terminal His-tags at both domains A and B may influence protein–protein interaction with the consequence that the mixture

• of the individually expressed domains shows a similarly rapid precipitation as domain B alone. However, some interaction between the individually expressed domains A and B can be concluded from their reduced productivity in comparison to domain B alone. Enzymatic synthesis of non-natural analogs of 2

Visible-light-induced nickel-catalyzed α-hydroxytrifluoroethylation of alkyl carboxylic acids: Access to trifluoromethyl alkyl acyloins

• Feng Chen,
• Xiu-Hua Xu,
• Zeng-Hao Chen,
• Yue Chen and
• Feng-Ling Qing

Beilstein J. Org. Chem. 2023, 19, 1372–1378, doi:10.3762/bjoc.19.98

• -difluoroethoxyphthalimide as the fluoroalkylating reagent failed to afford the desired product. According to our previous work [39] and literature precedent [27][35][38], a possible mechanism is proposed in Figure 2. The interaction between 2 and HE generates an electron donor–acceptor (EDA) complex A, which undergoes a

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

• with biomembranes via supramolecular interactions with the lipids and proteins that are embedded in these membranes. We can hypothesis that their mechanism of action occurs via a direct interaction with membrane proteins or by a modification of the biophysical properties of the membranes. It must be

• was selectively alkylated on the primary alcohol to produce 20.2 via the use of dibutyltin oxide as selective reagent for the alkylation of diols [109]. For this reaction, CsF was added to increase the reactivity of the alkyl bromide, likely by a combined effect that includes the interaction of the

Cyanothioacetamides as a synthetic platform for the synthesis of aminopyrazole derivatives

• Valeriy O. Filimonov,
• Alexandra I. Topchiy,
• Vladimir G. Ilkin,
• Tetyana V. Beryozkina and
• Vasiliy A. Bakulev

Beilstein J. Org. Chem. 2023, 19, 1191–1197, doi:10.3762/bjoc.19.87

• -enethioamides with hydrazine and its derivatives, the interaction proceeds with the participation of cyano- and enamine groups, not affecting the thiocarbamoyl group, and leads to the formation of 4-thiocarbamoylpyrazoles. A synthesis method has been developed and a series of 1-substituted-4-thiocarbamoyl

•  1D). Results and Discussion Considering that the construction of the pyrazole cycle can be carried out by the interaction of hydrazine with 1,3-bielectrophilic reagents, we paid attention to the structure of 2-cyanothioacetamides 1 and 3-amino-2-cyanoprop-2-enethioamides 2 [22] which combine in one

• molecule cyano- and thioamide groups, as well as a fragment of enamine, each in principle being capable of interaction with hydrazine (3a) (Figure 2). First, we have studied the reaction of thioamides 1a–c with hydrazine (3a). It was found that the reaction proceeds smoothly in ethanol at 80 °C to form 3,5

Exploring the role of halogen bonding in iodonium ylides: insights into unexpected reactivity and reaction control

• Carlee A. Montgomery and
• Graham K. Murphy

Beilstein J. Org. Chem. 2023, 19, 1171–1190, doi:10.3762/bjoc.19.86

• -hole bond is the non-covalent inter- or intramolecular interaction between the σ-hole of a group IV–VII atom with the electron-rich site of Lewis bases such as anions, hydrides, or even π electrons [24][30]. Halogen bonding is a subset of this bonding classification, represented by the generic bonding

• negative electrostatic potential (VS,min) of the acceptor [46][48][51][52], but also by other factors [53][54][55][56][57] including hydrogen bonding [31][48], solvent polarity [47][58], the Lewis basicity of the acceptor [46][50] and by sterics [46]. As with any interatomic interaction, the energy of a

• halogen bond lengths and their interaction energies [66][67][68][69][70][71]. Comparing the VS,max of select iodine-containing molecules shows that the electrostatic potential for molecular iodine (I-1) was 0.049 e, significantly greater than that of iodobenzene (I-2, 0.027 e) [70][72], though identical

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

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

• carbonyl groups of the urea fragment are observed (Figure 4). Values of spin–spin interaction constants 3JCH equal to 5.3–6.0 Hz indicate the cis-orientation of the vinyl proton and the carbonyl (for 4a, blue) or the carboxyl group (for 5a, red) relative to the double bond [24][25][26]. The values of spin

• –spin interaction constants of other doublets (2JCH = 1.3–1.5 Hz) indicate the position of the carboxyl (for 4a, red) or carbonyl (for 5a, blue) groups through two bonds relative to the olefinic proton. The structure of compound 5a was additionally confirmed by X-ray structural analysis data (Figure 5

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

• -c]pyridines. From the analysis of the literature data [2][40][41][42][43], we suggested that the interaction of furanic amines with various aldehydes in an acidic media should be accompanied by the formation of the corresponding imine, the generation of the iminium cation, and subsequent Pictet

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

• components, asymmetric products containing a nitrogen-substituted stereocenter can be obtained. Chiral organocatalysts can easily influence asymmetric aza-Friedel–Crafts reactions. The asymmetric induction is attributed to the formation of a chiral complex through a noncovalent interaction with the imine

• . The products 16 were achieved with excellent enantioselectivites which were attributed to an attractive interaction between the indole ring and the anthracene substituent of the catalyst’s framework (Scheme 5) [29]. In 2018, Piersanti and co-workers developed a phosphoric acid-catalyzed cascade

• -unsubstituted pyrroles/indoles 4/9 and isoquinoline-1,3,4(2H)-trione-1-imines 45 installing an aza-quaternary stereocenter in isoquinoline-1,3(2H,4H)-dione frameworks 46/47. The spinol-derived catalyst P15 was applied for the asymmetric induction through H-bonding interaction with the NH group of the

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

• 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 aliphatic nitriles from cyclobutanone oxime mediated by sulfuryl fluoride (SO₂F₂)

• Xian-Lin Chen and
• Hua-Li Qin

Beilstein J. Org. Chem. 2023, 19, 901–908, doi:10.3762/bjoc.19.68

• interaction between the drug candidate and the target protein, to further improve the efficacy of the potential drug [9]. The nitrile group can also function as a metabolic blocking site to inhibit the oxidative metabolism of molecules to improve metabolic stability in vivo [10]. Consequently, the development

A fluorescent probe for detection of Hg²⁺ ions constructed by tetramethyl cucurbit[6]uril and 1,2-bis(4-pyridyl)ethene

• Xiaoqian Chen,
• Naqin Yang,
• Yue Ma,
• Xinan Yang and
• Peihua Ma

Beilstein J. Org. Chem. 2023, 19, 864–872, doi:10.3762/bjoc.19.63

• cucurbit[6]uril (TMeQ[6]) and 1,2-bis(4-pyridyl)ethene (G) were used to construct a supramolecular fluorescent probe G@TMeQ[6]. The host–guest interaction between TMeQ[6] and G was investigated using 1H NMR spectroscopy, single-crystal X-ray diffraction and various experimental techniques. The results show

• detection of heavy metal ions. Results and Discussion The interactions of G with TMeQ[6] UV–vis spectroscopy analysis The binding interaction between G and TMeQ[6] in aqueous solution was studied using UV–vis absorption spectroscopy. Figure 2a shows that the absorbance of G decreases with the addition of

• complex with a molar ratio of 1:1. Fluorescent spectroscopic analysis The interaction between G and TMeQ[6] in aqueous solution was investigated using fluorescence titration experiments. The fluorescence titration curve (Figure 3a) shows that at the excitation wavelength of 351 nm, G has an emission peak

Pyridine C(sp²)–H bond functionalization under transition-metal and rare earth metal catalysis

• Haritha Sindhe,
• Malladi Mounika Reddy,
• Karthikeyan Rajkumar,
• Akshay Kamble,
• Amardeep Singh,
• Anand Kumar and
• Satyasheel Sharma

Beilstein J. Org. Chem. 2023, 19, 820–863, doi:10.3762/bjoc.19.62

• styrenes 64 using a Ni–Al bimetallic system and NHC ligand 65 through intermolecular hydroarylation with high levels of enantio- and regioselectivity in the alkylated products 66 (Scheme 13). Also, the authors performed DFT studies revealing the reaction mechanism and supported that the interaction of the

Synthesis of substituted 8H-benzo[h]pyrano[2,3-f]quinazolin-8-ones via photochemical 6π-electrocyclization of pyrimidines containing an allomaltol fragment

• Constantine V. Milyutin,
• Andrey N. Komogortsev,
• Boris V. Lichitsky,
• Mikhail E. Minyaev and
• Valeriya G. Melekhina

Beilstein J. Org. Chem. 2023, 19, 778–788, doi:10.3762/bjoc.19.58

• were not optimal and the process could be significantly improved. In order to employ the aforementioned approach for the preparation of pyrimidines containing an allomaltol moiety we initially selected the interaction of enaminone 13a with cyanamide as a model reaction. We varied time and temperature

• for the formation of pyrimidines 9 is presented in Scheme 3. At first, intermediate A is formed by Michael addition of cyanamide to enaminone 13. Further elimination of dimethylamine leads to cyanoenaminone B. Next, interaction of the cyano group with dimethylamine results in the formation of

Photocatalytic sequential C–H functionalization expediting acetoxymalonylation of imidazo heterocycles

• Deepak Singh,
• Shyamal Pramanik and
• Soumitra Maity

Beilstein J. Org. Chem. 2023, 19, 666–673, doi:10.3762/bjoc.19.48

• plays a crucial role in activating IP towards the photoredox coupling reaction. Shifting of protons in the 1H NMR spectrum of 2-phenylimidazo[1,2-a]pyridine (1a) in the presence of Zn(OAc)2 in CDCl3 indicates a weak interaction of Zn(OAc)2 with 1a (see Supporting Information File 1 for details) [20][21

• quenching study (Scheme 3F), expressed that the photoredox reaction started with the reductive generation of a malonyl radical from bromomalonate by interaction with the photocatalyst. Analyzing all the observations from the above mechanistic studies, we propose a plausible mechanism involving sequential

pH-Responsive fluorescent supramolecular nanoparticles based on tetraphenylethylene-labelled chitosan and a six-fold carboxylated tribenzotriquinacene

• Nan Yang,
• Yi-Yan Zhu,
• Wei-Xiu Lin,
• Yi-Long Lu and
• Wen-Rong Xu

Beilstein J. Org. Chem. 2023, 19, 635–645, doi:10.3762/bjoc.19.45

• synthesized a new chitosan bioconjugate CS-TPE with varying amounts of TPE labelling. It can self-assemble into fluorescent polymeric nanoparticles in an aqueous solution at pH 5.3, either alone or as a guest by electrostatic interaction with the TBTQ-C6 host. These nanoparticles were disassembled upon

• composed of TBTQ-C6, as illustrated in Scheme 1. Due to the electrostatic interaction between the host and guest molecules, pH is considered an influential control factor in regulating the assembly and disassembly of supramolecular nanoparticles, as changes in pH affect the protonation degree of the

Enolates ambushed – asymmetric tandem conjugate addition and subsequent enolate trapping with conventional and less traditional electrophiles

• Péter Kisszékelyi and
• Radovan Šebesta

Beilstein J. Org. Chem. 2023, 19, 593–634, doi:10.3762/bjoc.19.44

• 61. On the other hand, the sterically bulky diphenylphosphorane group afforded the (R,R,R)-diastereoisomer 63 as the main product. The large protecting group likely overrides the repulsive interaction between the enolate and a phenyl group in a preferred synclinal Mg-bound arrangement of the reagents

Direct C2–H alkylation of indoles driven by the photochemical activity of halogen-bonded complexes

• Martina Mamone,
• Giuseppe Gentile,
• Jacopo Dosso,
• Maurizio Prato and
• Giacomo Filippini

Beilstein J. Org. Chem. 2023, 19, 575–581, doi:10.3762/bjoc.19.42

• deuterated acetonitrile (Figure 3). Interestingly, a change in chemical shift of the diagnostic α-protons of 2a was displayed upon addition of increasing amounts of DABCO, suggesting the presence of the halogen-bonding interaction [30]. More precisely, the 1H NMR signal of the α-hydrogens (Hα) within 2a was

• found to shift to lower ppm values because the Hα nuclei have been affected by higher electron density caused by the formation of the halogen-bonded complex between 2a and DABCO. To confirm that the shift of Hα was indeed produced by a halogen-bonding interaction, 19F NMR analysis of compound 2d, which

A new oxidatively stable ligand for the chiral functionalization of amino acids in Ni(II)–Schiff base complexes

• Alena V. Dmitrieva,
• Oleg A. Levitskiy,
• Yuri K. Grishin and
• Tatiana V. Magdesieva

Beilstein J. Org. Chem. 2023, 19, 566–574, doi:10.3762/bjoc.19.41

• isomer (see Figure 2). The presence of the tert-butyl group induces an additional dispersion interaction between this group and the benzyl fragment in the ʟ-(AlaNi)L7 complex, bringing the benzyl group and the o-phenylene moiety even closer to each other (the distance between the C20 and C8 atoms is 3.45