Configuration–packing synergy enabling integrated crystalline-state RTP and amorphous-state TADF

• Ruiyan Wang and
• Yunan Wu

Beilstein J. Org. Chem. 2026, 22, 224–236, doi:10.3762/bjoc.22.16

• states, intermolecular interactions enhance spin–orbit coupling and crystallinity suppresses nonradiative decay, thereby activating RTP. This work achieves an integrated “crystalline-state RTP–amorphous-state TADF” regulation within a single molecule. Keywords: imide; π–π stacking; room-temperature

• configuration design and material-scale packing/confinement engineering to enable the controlled switching between RTP and TADF. Among the potential receptor units, imide, with its strong electron-withdrawing nature and prominent n→π* contribution from the two carbonyl groups, offers a dual advantage: it

• effective pathway for the singlet-to-triplet transition according to the El-Sayed rule, thus enhancing the ISC rate and RTP visibility. On the other hand, imide, when used as an acceptor with carbazole or phenoxazine as donors, forms a small energy gap with spatially separated frontier orbitals, thereby

Preparation of spirocyclic oxindoles by cyclisation of an oxime to a nitrone and dipolar cycloaddition

• Beth L. Ritchie,
• Alexandra Longcake and
• Iain Coldham

Beilstein J. Org. Chem. 2025, 21, 1890–1896, doi:10.3762/bjoc.21.146

• stereoisomer has the ring-junction NC–H bond, the imide carbonyls, and the oxindole carbonyl all cis to one another across the two newly formed rings. This must arise from a preference for an exo transition state that places the incoming maleimide away from the oxindole carbonyl. The cascade chemistry allows

Unique halogen–π association detected in single crystals of C–N atropisomeric N-(2-halophenyl)quinolin-2-one derivatives and the thione analogue

• Mai Uchibori,
• Nanami Murate,
• Kanako Shima,
• Tatsunori Sakagami,
• Ko Kanehisa,
• Gary James Richards,
• Akiko Hori and
• Osamu Kitagawa

Beilstein J. Org. Chem. 2025, 21, 1748–1756, doi:10.3762/bjoc.21.138

• diverse C–N atropisomeric compounds possessing carboxamide, imide, lactam, sulfonamide, indole, pyrrole, imidazole, carbazole and amine skeletons have been reported by many groups [1][2][3][4][5][6][7][8][9]. C–N atropisomers are attractive compounds from the viewpoint of not only synthetic organic

Facile synthesis of hydantoin/1,2,4-oxadiazoline spiro-compounds via 1,3-dipolar cycloaddition of nitrile oxides to 5-iminohydantoins

• Juliana V. Petrova,
• Varvara T. Tkachenko,
• Victor A. Tafeenko,
• Anna S. Pestretsova,
• Vadim S. Pokrovsky,
• Maxim E. Kukushkin and
• Elena K. Beloglazkina

Beilstein J. Org. Chem. 2025, 21, 1552–1560, doi:10.3762/bjoc.21.118

• greater involvement of the N1 electron pair in conjugation with the imide fragment of the dipolarophile and its deactivation in the reaction with nitrile oxide. This pattern is consistent with the one previously observed when studying the reactions of these dipolarophiles with nitrile imines [22]. It is

Advances in nitrogen-containing helicenes: synthesis, chiroptical properties, and optoelectronic applications

• Meng Qiu,
• Jing Du,
• Nai-Te Yao,
• Xin-Yue Wang and
• Han-Yuan Gong

Beilstein J. Org. Chem. 2025, 21, 1422–1453, doi:10.3762/bjoc.21.106

• region. X,N-containing helicenes (X = O, S or Se) Imide functional groups are well recognized for their strong electron-accepting character, making them valuable moieties in the design of optoelectronic materials. When incorporated into π-conjugated frameworks, imide groups can significantly modulate

• electronic structures and enhance properties such as fluorescence efficiency, charge transport, and chiroptical responses. In this section, we begin by summarizing representative imide-functionalized helicenes, highlighting their structural features and photophysical performances. In 2020, Ravat’s group

Recent advances and future challenges in the bottom-up synthesis of azulene-embedded nanographenes

• Bartłomiej Pigulski

Beilstein J. Org. Chem. 2025, 21, 1272–1305, doi:10.3762/bjoc.21.99

• to the dication induced an aromaticity switch, resulting in the pentagon–heptagon pair adopting an aromatic character. The group later extended this strategy to scaffold 91 decorated with two imide substituents, which was isolated in 4% yield [66]. Annulation of substituted azulenes Scholl-type

• reacts effectively with imide to yield the non-alternant PAH 129 in 47% yield (Scheme 17) [85]. The resulting non-alternant isomer of perylenebisimide 129 exhibits strongly red-shifted absorption (λmax = 1041 nm) and an azulene-like electronic structure. The optical absorption of PAH 129 is strongly

Recent total synthesis of natural products leveraging a strategy of enamide cyclization

• Chun-Yu Mi,
• Jia-Yuan Zhai and
• Xiao-Ming Zhang

Beilstein J. Org. Chem. 2025, 21, 999–1009, doi:10.3762/bjoc.21.81

• triggered a Grob fragmentation process of hemiaminal 16 and afforded the imide compound 17. Final regioselective reduction of one of the two carbonyls on the imide completed the synthesis of (−)-phlegmariurine B. Annulation Total syntheses of cephalotaxine and cephalezomine H The [2 + 3] annulation of

Recent advances in controllable/divergent synthesis

• Jilei Cao,
• Leiyang Bai and
• Xuefeng Jiang

Beilstein J. Org. Chem. 2025, 21, 890–914, doi:10.3762/bjoc.21.73

• thiols act as stoichiometric reductants. Mechanistic insights, elucidated through control experiments and DFT calculations, revealed that photoexcitation of diazo imide 41 triggers nitrogen extrusion (ΔG‡ = +10.0 kcal·mol−1), generating the triplet carbene intermediate Int-45. In DCM, this species

• the fluorosulfonyl imide to form sulfonyliminium cations Int-95. These then add to the activated phenylacetylene to construct the S–C bond, followed by intramolecular 1,5-hydrogen migration and aqueous workup to remove benzaldehyde, yielding the target sulfonylimine products. Both original

Photochemically assisted synthesis of phenacenes fluorinated at the terminal benzene rings and their electronic spectra

• Yuuki Ishii,
• Minoru Yamaji,
• Fumito Tani,
• Kenta Goto,
• Yoshihiro Kubozono and
• Hideki Okamoto

Beilstein J. Org. Chem. 2025, 21, 670–679, doi:10.3762/bjoc.21.53

• molecules displayed high hole mobility [20][21][22][23][24][25][26] and imide-fused phenacenes served as n-type organic semiconductors [27]. It was also disclosed that donor–acceptor-type phenacenes provided environment-dependent fluorophores showing solvatochromic fluorescence behavior [28][29]. Because

N-Glycosides of indigo, indirubin, and isoindigo: blue, red, and yellow sugars and their cancerostatic activity

• Peter Langer

Beilstein J. Org. Chem. 2024, 20, 2840–2869, doi:10.3762/bjoc.20.240

• application of the Mukaiyama redox condensation using N-iodosuccinic imide (NIS) afforded 10b. Hydrogenation resulted in defunctionalization to give 10c. Transformation of OH-4 to a triflate and subsequent reaction with sodium azide afforded gluco-configured product 10d. The latter was transformed to

Synthesis and antimycotic activity of new derivatives of imidazo[1,2-a]pyrimidines

• Dmitriy Yu. Vandyshev,
• Daria A. Mangusheva,
• Khidmet S. Shikhaliev,
• Kirill A. Scherbakov,
• Oleg N. Burov,
• Alexander D. Zagrebaev,
• Tatiana N. Khmelevskaya,
• Alexey S. Trenin and
• Fedor I. Zubkov

Beilstein J. Org. Chem. 2024, 20, 2806–2817, doi:10.3762/bjoc.20.236

• polyfunctional precursors 1, 2, and 3, two pathways are theoretically possible (Scheme 2 and Scheme 3). The first one involves the N-nucleophilic Michael addition to the activated multiple bond of the imide, leading to the formation of linear intermediates 6 or 8 (pathways A1 and B1) at the expense of the endo

Synthesis and characterization of 1,2,3,4-naphthalene and anthracene diimides

• Adam D. Bass,
• Daniela Castellanos,
• Xavier A. Calicdan and
• Dennis D. Cao

Beilstein J. Org. Chem. 2024, 20, 1767–1772, doi:10.3762/bjoc.20.155

• -) derivatization of aromatic scaffolds because it can be exploited to stabilize the longer (hetero)acenes. In contrast to cata-benzannulation, cata-imide-annulation does not perturb aromaticity patterns and further introduces inductive stabilization of frontier MO levels, which has enabled the production of n-type

• . Heating 5 with hexylamine or aniline in refluxing acetic acid successfully led to the formation of the targeted aromatic diimides bearing either N-hexyl (7-Hex) or N-phenyl (7-Ph) substitutions in good yields. The same strategy was employed to create the imide-capped anthracenes 8-Hex and 8-Ph

• evaporation of CH2Cl2/MeOH solutions and characterized by X-ray crystallography. 7-Ph crystallizes in the Pbcn space group into a solvent superstructure of π-stacked columns of 7-Ph. The imide groups are pointed in alternating directions within a stack. While this may occur in part as a consequence of the

Synthesis and physical properties of tunable aryl alkyl ionic liquids based on 1-aryl-4,5-dimethylimidazolium cations

• Stefan Fritsch and
• Thomas Strassner

Beilstein J. Org. Chem. 2024, 20, 1278–1285, doi:10.3762/bjoc.20.110

• -donating substituents in different positions of the phenyl ring and the bis(trifluoromethylsulfonyl)imide (NTf2) anion. We investigated the effect of additional methyl groups in the backbone of the imidazolium core on the physical properties regarding viscosity, conductivity and electrochemical window

• weakly coordinating anions like bis(trifluoromethylsulfonyl)imide [NTf2]− [25]. In addition, dicationic salts or anions containing metal complexes have been described [26][27]. Due to the numerous combinations of different anions and cations, ILs can also be described as designer solvents [28]. We

• 6.3 V, which is currently the largest window for a bis(trifluoromethylsulfonyl)imide tunable aryl alkyl ionic liquid. Temperature-dependent viscosity measurement of NTf2− TAAILs 37–63 with a butyl chain and different aryl substitution R. Conductivity of NTf2− TAAILs 37–63 measured at 25 °C. Compounds

Possible bi-stable structures of pyrenebutanoic acid-linked protein molecules adsorbed on graphene: theoretical study

• Yasuhiro Oishi,
• Motoharu Kitatani and
• Koichi Kusakabe

Beilstein J. Org. Chem. 2024, 20, 570–577, doi:10.3762/bjoc.20.49

• expected to appear in the case of succinimide substitutions by proteins? To answer this question, we consider imide substitutions extensively. In principle, if the effect of substitution only provides a weak perturbation, the potential energy surface is only slightly changed and the barrier is maintained

Entry to new spiroheterocycles via tandem Rh(II)-catalyzed O–H insertion/base-promoted cyclization involving diazoarylidene succinimides

• Alexander Yanovich,
• Anastasia Vepreva,
• Ksenia Malkova,
• Grigory Kantin and
• Dmitry Dar’in

Beilstein J. Org. Chem. 2024, 20, 561–569, doi:10.3762/bjoc.20.48

• from each of the bromo-substituted alcohols used by us have two main pathways of transformation under the action of base: 1) exo-tet cyclization with substitution of the bromine atom and formation of the spirocycle, and 2) migration of the exocyclic double C=C bond into the imide cycle (the process is

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

• ), it was non-scalable and displayed low modularity. Indeed, the imide groups along with their substituents were introduced at a rather early stage of the synthesis, with the ultimate synthetic step being the formation of the thiepine ring via a two-fold nucleophilic aromatic substitution by sodium

• sulfide (Na2S). Since the nature of the imide substituents is very important to control the solid state molecular arrangement, the same authors revised their initial synthetic route to allow for a late stage introduction of the imide groups, thus leading to the preparation of a series of variously

• temperature required for the imide formation, as high temperature (>130 °C) induced undesired thermally-activated S-extrusion as side-reaction. According to this new synthetic route, compound 3a carrying octyl substituents was obtained on a gram-scale in 7 steps from acenaphthene, in 14% overall yield. The

1-Butyl-3-methylimidazolium tetrafluoroborate as suitable solvent for BF₃: the case of alkyne hydration. Chemistry vs electrochemistry

• Marta David,
• Elisa Galli,
• Richard C. D. Brown,
• Marta Feroci,
• Fabrizio Vetica and
• Martina Bortolami

Beilstein J. Org. Chem. 2023, 19, 1966–1981, doi:10.3762/bjoc.19.147

• anions could coordinate the Lewis acid BF3 through the negatively charged oxygen [107], decreasing availability of BF3 for catalysis. Otherwise, ILs possessing bis(trifluoromeylsulfonyl)imide and hexafluorophosphate anions afforded hydrated product 2a with slightly better yields (87%) compared to those

N-Boc-α-diazo glutarimide as efficient reagent for assembling N-heterocycle-glutarimide diads via Rh(II)-catalyzed N–H insertion reaction

• Grigory Kantin,
• Pavel Golubev,
• Alexander Sapegin,
• Alexander Bunev and
• Dmitry Dar’in

Beilstein J. Org. Chem. 2023, 19, 1841–1848, doi:10.3762/bjoc.19.136

• at the α-position have not yet been studied. Typically, two primary strategies are employed to build an N-heterocycle-glutarimide diad. The first involves assembling a heterocyclic fragment utilizing glutamic acid imide (2, Scheme 1, route A), while the second involves alkylating NH-heterocycle with

• procedures detailed below (Scheme 2). Glutarimide (7), which is commercially available, was (dimethylamino)methylenated at the α-position with the Bredereck's reagent before adding the Boc group to the imide nitrogen atom of the crude enamine. The interim derivative 8 was obtained with a yield of 53% over

• two steps and readily entered the diazo transfer reaction with 4-nitrophenylsulfonyl azide (4-NsN3). The resulting diazo reagent 5 was produced in a high yield after undergoing straightforward chromatographic purification. The use of a Boc group at the nitrogen atom of the diazo imide significantly

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

• . In 1-iso, only the two hexagonal imide groups affect the HOMO/LUMO localization, whereas the pentagonal central imide group is little affected. In 2-iso, both pentagonal are relevant to the HOMO/LUMO localization, whereas the two terminal benzene rings are little affected. The cartesian coordinates

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

• enhanced electron hopping and reduced geminate recombination. Qx12 and Qx13 achieved remarkable PCEs of 13.31% and 16.64%, respectively, with PBDB-TF donor in OSC devices [28]. Zhu et al. reported a modification in Qx13 by incorporating an imide-functionalized Qx moiety in its core and end-capping groups

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

The effect of dark states on the intersystem crossing and thermally activated delayed fluorescence of naphthalimide-phenothiazine dyads

• Liyuan Cao,
• Xi Liu,
• Xue Zhang,
• Jianzhang Zhao,
• Fabiao Yu and
• Yan Wan

Beilstein J. Org. Chem. 2023, 19, 1028–1046, doi:10.3762/bjoc.19.79

• was observed for the dyads containing the native PTZ unit, and the prompt and delayed fluorescence lifetimes changed with different aryl substituents on the imide part. In polar solvents, no TADF was observed. For the dyads with the PTZ unit oxidized, no TADF was observed as well. Femtosecond

Intermediates and shunt products of massiliachelin biosynthesis in Massilia sp. NR 4-1

• Till Steinmetz,
• Blaise Kimbadi Lombe and
• Markus Nett

Beilstein J. Org. Chem. 2023, 19, 909–917, doi:10.3762/bjoc.19.69

• protein RS02200: FAAL: fatty acyl-AMP ligase; ACP: acyl carrier protein; KS: β-ketoacyl synthase; AT: acyltransferase; KR: ketoreductase; C: condensation; A: adenylation; MT: methyltransferase; PCP: peptidyl carrier protein. A discrete enzyme, the thiazolinyl imide reductase RS02195 (Red), catalyzes the

Transition-metal-catalyzed domino reactions of strained bicyclic alkenes

• Austin Pounder,
• Eric Neufeld,
• Peter Myler and
• William Tam

Beilstein J. Org. Chem. 2023, 19, 487–540, doi:10.3762/bjoc.19.38

• -trifluoromethyl substituent forming the ketone product in <10% yield. While substitution of the norbornene was tolerated, both EWGs and EDGs hindered the reaction. Upon several mechanistic studies, the authors proposed the catalytic cycle begins with the oxidative addition of the active Ni(0) catalyst to imide 27

Friedel–Crafts acylation of benzene derivatives in tunable aryl alkyl ionic liquids (TAAILs)

• Swantje Lerch,
• Stefan Fritsch and
• Thomas Strassner

Beilstein J. Org. Chem. 2023, 19, 212–216, doi:10.3762/bjoc.19.20

• lithium bis(trifluoromethylsulfonyl)imide (LiNTf2). All reactions are generally tolerant towards different aryl substitutions, substitution patterns, alkyl chain lengths and can be carried out in a multigram scale [57]. The acylation of the electron-rich benzene derivative anisole with acetic anhydride