Controlling the reactivity of La@C₈₂ by reduction: reaction of the La@C₈₂ anion with alkyl halide with high regioselectivity

• Yutaka Maeda,
• Saeka Akita,
• Mitsuaki Suzuki,
• Michio Yamada,
• Takeshi Akasaka,
• Kaoru Kobayashi and
• Shigeru Nagase

Beilstein J. Org. Chem. 2023, 19, 1858–1866, doi:10.3762/bjoc.19.138

• structure is described as La3+C823−. We previously investigated the reaction of M@C2v-C82 ions (M = Y, La, Ce) with disilirane, which possesses high reactivity toward electron acceptors [16][17]. Interestingly, the reactivity of M@C2v-C82 toward disilirane was increased by the one-electron oxidation of M

Recent advancements in iodide/phosphine-mediated photoredox radical reactions

• Tinglan Liu,
• Yu Zhou,
• Junhong Tang and
• Chengming Wang

Beilstein J. Org. Chem. 2023, 19, 1785–1803, doi:10.3762/bjoc.19.131

• electron release. The radical intermediate A could then be captured by a series of different radical acceptors. Finally, the initial NaI/PPh3 complex I was regenerated from complex III through an electron injection/reduction process. This article aims to provide a comprehensive overview of the latest

Active-metal template clipping synthesis of novel [2]rotaxanes

• Cătălin C. Anghel,
• Teodor A. Cucuiet,
• Niculina D. Hădade and
• Ion Grosu

Beilstein J. Org. Chem. 2023, 19, 1776–1784, doi:10.3762/bjoc.19.130

• ) [30][31], metal-ion template (coordination bonds [22][32], ion-dipol [16], donor–acceptor (charge transfer, π–π stacking) [30][33], and oligoamide macrocycle-hydrogen acceptors (hydrogen bonding) [20][34]. In active-metal template methods (Figure 1) the metal ion acts both as template and catalyst for

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

• conduction of electrons [16]. Perylene diimide derivatives display good electronic mobilities (10−3 to 10−1 cm2 V−1 s−1) and are considered suitable electron acceptors for photovoltaic applications [17][18][19][20]. Pyrene derivatives have also been widely investigated in recent decades. They exhibit

Effects of the aldehyde-derived ring substituent on the properties of two new bioinspired trimethoxybenzoylhydrazones: methyl vs nitro groups

• Dayanne Martins,
• Roberta Lamosa,
• Talis Uelisson da Silva,
• Carolina B. P. Ligiero,
• Sérgio de Paula Machado,
• Daphne S. Cukierman and
• Nicolás A. Rey

Beilstein J. Org. Chem. 2023, 19, 1713–1727, doi:10.3762/bjoc.19.125

• the structures (Figure 2A) shows that spatial arrangements are nearly the same and even the crystallization water molecules were allocated in nearby sites, interacting as H-acceptors in a hydrogen bond with the respective N2H groups. In spite of these similarities, the compounds were indexed in

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

• ), organic field-effect transistors (OFETs), organic-light emitting diodes (OLEDs) and other organic electronic technologies. Notably, the potential of quinoxaline derivatives as non-fullerene acceptors in OSCs, auxiliary acceptors and bridging materials in DSSCs, and n-type semiconductors in transistor

• transport applications. Furthermore, ongoing research efforts aimed at enhancing their performance and addressing key challenges in various applications are presented. Keywords: electron transport materials; non-fullerene acceptors; n-type semiconductors; organic electronics; quinoxalines; Introduction

• high electron mobility and efficient charge transfer. In particular, Qx derivatives find use as non-fullerene acceptors (NFAs) in OSCs and as essential building blocks in sensitizers for DSSCs. The significance of Qx extends beyond to thermally activated delayed fluorescence (TADF) emitters and

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

• . It has been reported that the performance of HLCT fluorophores greatly depends on the strength of donors, acceptors, and π spacers and the building blocks of HLCT should be carefully selected to regulate appropriate electron push–pull strength [32][35][47][48]. Here, a novel chromophore, 4,9-bis(9-(4

Benzoimidazolium-derived dimeric and hydride n-dopants for organic electron-transport materials: impact of substitution on structures, electrochemistry, and reactivity

• Swagat K. Mohapatra,
• Khaled Al Kurdi,
• Samik Jhulki,
• Georgii Bogdanov,
• John Bacsa,
• Maxwell Conte,
• Tatiana V. Timofeeva,
• Seth R. Marder and
• Stephen Barlow

Beilstein J. Org. Chem. 2023, 19, 1651–1663, doi:10.3762/bjoc.19.121

• reduction peak, while the reduction peak of the cation is seen in the voltammograms of both 1gH and 1g2 following scanning of the irreversible oxidation peaks. Acceptors used to examine reactivity of DMBI-H and (DMBI)2 derivatives. a) Temporal evolution of the absorbance at 1030 nm, corresponding to an

A series of perylene diimide cathode interlayer materials for green solvent processing in conventional organic photovoltaics

• Kathryn M. Wolfe,
• Shahidul Alam,
• Eva German,
• Fahad N. Alduayji,
• Maryam Alqurashi,
• Frédéric Laquai and
• Gregory C. Welch

Beilstein J. Org. Chem. 2023, 19, 1620–1629, doi:10.3762/bjoc.19.119

• ], where the BHJ used was PM6:Y6 and PCEs were found to be comparable to that of PFN-Br with PCEs of over ≈13%. Results and Discussion Design strategy Previously, the benzyl-annulated dimers of the ethyl propyl perylene diimide (tPDI2-N-R; Figure 2) were reported as non-fullerene acceptors for OPVs

• , reaching PCEs of ≈6% [23]. Realizing that these materials are suitable electron acceptors, it was hypothesized that the monomeric species would be suitable candidates for use as CILs as the planar structure is more likely to induce ordered microstructures, which is ideal for CILs as a means to provide

α-(Aminomethyl)acrylates as acceptors in radical–polar crossover 1,4-additions of dialkylzincs: insights into enolate formation and trapping

• Angel Palillero-Cisneros,
• Paola G. Gordillo-Guerra,
• Fernando García-Alvarez,
• Olivier Jackowski,
• Franck Ferreira,
• Fabrice Chemla,
• Joel L. Terán and
• Alejandro Perez-Luna

Beilstein J. Org. Chem. 2023, 19, 1443–1451, doi:10.3762/bjoc.19.103

• that α-(aminomethyl)acrylates are suitable acceptors for 1,4-additions of dialkylzincs in aerobic conditions. The air-promoted radical–polar crossover process involves the 1,4-addition of an alkyl radical followed by homolytic substitution at the zinc atom of dialkylzinc. Coordination of the nitrogen

• protodemetalation to provide ultimately the 1,4-addition adduct. In the presence of carbonyl acceptors, aldol condensation occurs providing overall a tandem 1,4-addition–aldol process. When a tert-butanesulfinyl moiety is present on the nitrogen atom, these electrophilic substitution reactions occur with good

• . Trialkylboranes can react in a similar way with enones [3] whereas, distinctively, suitable acceptors for the reaction with dialkylzinc reagents also include α,β-unsaturated carboxylic acid derivatives such as α,β-unsaturated (di)esters [4][5], N-enoyloxazolidinones [6][7], N-enoyloxazolidines [8], or

Selective construction of dispiro[indoline-3,2'-quinoline-3',3''-indoline] and dispiro[indoline-3,2'-pyrrole-3',3''-indoline] via three-component reaction

• Ziying Xiao,
• Fengshun Xu,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2023, 19, 1234–1242, doi:10.3762/bjoc.19.91

• as Michael acceptors, 1,3-dipolarophiles, 1,4-dienophiles and other multiple substrates. They have been widely employed as key component to finish many multicomponent and domino reactions [26][27][28][29][30][31][32][33][34][35]. Recently, the Michael adduct of 3-methyleneoxindoles with various

Enabling artificial photosynthesis systems with molecular recycling: A review of photo- and electrochemical methods for regenerating organic sacrificial electron donors

• Grace A. Lowe

Beilstein J. Org. Chem. 2023, 19, 1198–1215, doi:10.3762/bjoc.19.88

• shown for the one-electron-reduced viologen species ([methyl viologen]•− −0.59 V vs SCE, [ethylcarboxy viologen]•− −0.49 V vs SCE, [ethylamide viologen]•− −0.42 V vs SCE) [59]. Viologens usually act as electron acceptors in aqueous RFB anolytes. In general, RFB anolytes are optimized to have very low

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

• as an electron donor–acceptor complex) [121], and this bonding description has recently been used to support proposals for single electron transfer (SET) reaction pathways between iodonium ylides and various halogen bond acceptors. Alternatively, halogen-bonded complexes of iodonium ylides could lead

• on the arene, these engaged with the ylide’s stronger σ-hole to block this site and diminish the ylide’s aggregation potential. However, intramolecular σ-hole blocking by halogen bond acceptors appears to be reversible, as these σ-holes do participate in reactions with extraneous Lewis basic

• reactants, presumably via equilibration between initially-formed adducts. And while the impact of these halogen bond acceptors on subsequent mechanistic events remains unknown, these represent an easily modified structural feature that may prove instrumental to discovering new reactivity patterns for

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

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

• various asymmetric chemical transformations. These compounds play a dual role in the catalytic cycle due to their intrinsic Brønsted acidity and the ability to H-bond formation. Organophosphoric acids can perform as both H-bond acceptors and donors. 1,1’-Bi-2-naphthol (BINOL) and 1,1’-spirobiindane-7,7

Asymmetric tandem conjugate addition and reaction with carbocations on acylimidazole Michael acceptors

• Brigita Mudráková,
• Renata Marcia de Figueiredo,
• Jean-Marc Campagne and
• Radovan Šebesta

Beilstein J. Org. Chem. 2023, 19, 881–888, doi:10.3762/bjoc.19.65

• organoboron reagents were realized [12]. Also, in terms of suitable Michael acceptors as substrates, unsaturated ketones, aldehydes, esters, thioesters, amides, alkenyl heterocycles and enoyl heterocycles became viable for conjugate additions. The maturity and robustness of this methodology is documented by

• , because of their particular chemical and physical properties [15]. In addition to ester/amide synthesis, enoyl imidazolides were developed as excellent Michael acceptors. Acylimidazoles are unique electrophiles that demonstrate moderate reactivity, relatively high stability, chemical selectivity, and high

• , imines, other Michael acceptors, or alkyl halides. Our group is developing trapping of metal enolates with stabilized carbocations and could show that magnesium enolates generated from enones [22], unsaturated amides [23], or heterocycles reacted with tropylium, dithiolylium or flavylium cations [24

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

• supramolecular systems derived from water-soluble macrocycles, including cyclodextrins (CDs), calix[n]arenes (CXs), cucurbiturils (CBs), and pillararenes have been widely studied [2][6][7][8]. Similar to those macrocyclic acceptors, tribenzotriquinacene (TBTQ) derivatives, a class of versatile host molecules

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

• developed a Lewis acid-promoted conjugate addition to unreactive Michael acceptors such as amides or vinyl heterocycles [60]. Trimethylsilyl triflate or boron trifluoride-activated unsaturated amides underwent highly efficient and enantioselective addition of Grignard reagents. When this methodology was

• alkenyl heteroarenes [61]. The aza-enolates were trapped with various Michael acceptors such as unsaturated ketones, esters, and amides (Scheme 25) [62]. The authors noted a strong substrate dependence of this process. The trapping reaction worked best with benzoxazole-derived substrate, while thiazole

• ferrocene ligands. All types of metal enolates generated via these processes were able to react with Michael acceptors and afforded the corresponding products in good yields. The alkynylation of enolates generated by conjugate addition was described by Teodoro and Silva (Scheme 32) [68]. Even though the

An accelerated Rauhut–Currier dimerization enabled the synthesis of (±)-incarvilleatone and anticancer studies

• Tharun K. Kotammagari,
• Sweta Misra,
• Sayantan Paul,
• Sunita Kunte,
• Rajesh G. Gonnade,
• Manas K. Santra and
• Asish K. Bhattacharya

Beilstein J. Org. Chem. 2023, 19, 204–211, doi:10.3762/bjoc.19.19

• reported in the literature is described. The reaction was discovered by Rauhut and Currier [5] in the year 1963. It is a nucleophile-catalyzed C–C bond-forming reaction between two Michael acceptors. This reaction provides access to diverse classes of densely functionalized molecules. Rauhut–Currier (RC

• intermolecular fashion to form a C–C bond between the two Michael acceptors. This whole process involves two intermolecular conjugate additions, which leads to low reactivity. In case of intramolecular RC reactions, a high reactivity is observed. This is due to one intermolecular and one intramolecular conjugate

Identification and determination of the absolute configuration of amorph-4-en-10β-ol, a cadinol-type sesquiterpene from the scent glands of the African reed frog Hyperolius cinnamomeoventris

• Angelique Ladwig,
• Markus Kroll and
• Stefan Schulz

Beilstein J. Org. Chem. 2023, 19, 167–175, doi:10.3762/bjoc.19.16

• slow reaction, but a 37% solution of formaldehyde in water/methanol proved to be successful (Table 1, entries 5–10). Nevertheless, two problems were encountered. First, the Diels–Alder products 9–11 proved to be also active Mannich acceptors, leading to the unwanted unsaturated ketone 20, a double

Combining the best of both worlds: radical-based divergent total synthesis

• Kyriaki Gennaiou,
• Antonios Kelesidis,
• Maria Kourgiantaki and
• Alexandros L. Zografos

Beilstein J. Org. Chem. 2023, 19, 1–26, doi:10.3762/bjoc.19.1

• drastically the radical stability, nucleophilicity, and selectivity of 139 [73]. Furnishing of the common scaffold 130 can be carried out via an attack of intermediates of this type (e.g., 139) on Michael acceptors. Tosyl group deprotection of 130, followed by selenium anhydride oxidation and catalytic

Redox-active molecules as organocatalysts for selective oxidative transformations – an unperceived organocatalysis field

• Elena R. Lopat’eva,
• Igor B. Krylov,
• Dmitry A. Lapshin and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2022, 18, 1672–1695, doi:10.3762/bjoc.18.179

• [74][76][80][86][87][88]. To facilitate the anodic oxidation of N-hydroxyphthalimide, basic pyridine derivatives are used as the N-hydroxyphthalimide proton acceptors [87]. In many cases electrolysis can be performed in the galvanostatic mode in a simple undivided cell, which is convenient for

• which are stable to self-decay are used in oxidative organocatalysis as hydrogen atom acceptors or one-electron oxidants (Scheme 17). The stability of cation radical to self-decay is achieved in bicyclic structures where the cleavage of a hydrogen atom from the carbon atom next to nitrogen is

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

• by cyclic voltammetry (Table 3) and acceptors 2 revealed no reduction peaks from 0 to −2.00 V vs SCE [5][6]. Therefore, this electroreductive coupling is initiated by the reduction of compounds 1. There are two possible reaction mechanisms for the reductive coupling of 1 with 2a as illustrated in

Introducing a new 7-ring fused diindenone-dithieno[3,2-b:2',3'-d]thiophene unit as a promising component for organic semiconductor materials

• Valentin H. K. Fell,
• Joseph Cameron,
• Alexander L. Kanibolotsky,
• Eman J. Hussien and
• Peter J. Skabara

Beilstein J. Org. Chem. 2022, 18, 944–955, doi:10.3762/bjoc.18.94

• evaporation, average mobilities of 14.20 ± 2.55 cm2 V−1 s−1, with a maximum value of 17.2 cm2 V−1 s−1 were achieved. In recent years, fused thiophene molecules also achieved outstanding performances in OPVs. This was especially driven by recent developments in non-fullerene acceptors (NFA) [29]. One prominent

Post-synthesis from Lewis acid–base interaction: an alternative way to generate light and harvest triplet excitons

• Hengjia Liu and
• Guohua Xie

Beilstein J. Org. Chem. 2022, 18, 825–836, doi:10.3762/bjoc.18.83

• acceptors Some Lewis acids have good solubility in common organic solvents, which makes it easy to fabricate films for optoelectronic applications [24]. Because of their strong electrophilicity [25], Lewis acids may dominate charge distributions of the fluorescent materials featured with electron-rich

• acids B(C6F5)3 and B(C6H5)3 as electron acceptors, respectively [29]. B(C6F5)3 displays high chemical stability and Lewis acidity [30]. Moreover, its good solubility endows the possibility to form Lewis acid–base adducts in films by solution processing. The strong electron attraction of the fluorine

• temperature. Figure 12 was reprinted from [29], Chemical Engineering Journal, vol. 380, by M. Zhang; G. Xie; Q. Xue; H. Wang, “Electroluminescence of intra-molecular exciplexes based on novel Lewis acid borane acceptors and a high triplet level donor”, article no. 122527, Copyright (2020), with permission