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

• further functionalised with (triisopropylsilyl)ethynyl [24] (6) or with 1,3-dithiole units [25] (7) by other research groups. The (triisopropylsilyl)ethynyl (TIPSE) groups are introduced to improve the solubility and solid-state order, fostering intermolecular π-orbital interactions [26]. Moreover

• intermolecular interactions, which are known to lead to a narrowing of the energy gap [3][61]. With a concentration series, an extinction coefficient of ε361 nm = 4.3 × 104 L mol−1 cm−1 could be determined for the band at 361 nm, whilst for the band at 540 nm, a coefficient of ε540 nm = 1.1 × 104 L mol−1 cm−1

First series of N-alkylamino peptoid homooligomers: solution phase synthesis and conformational investigation

• Maxime Pypec,
• Laurent Jouffret,
• Claude Taillefumier and
• Olivier Roy

Beilstein J. Org. Chem. 2022, 18, 845–854, doi:10.3762/bjoc.18.85

• backbone stabilization through intra-residue hydrogen bonds but also to intermolecular associations. The high capacity of N-(methylamino)peptoids to establish intermolecular hydrogen bonds was notably deduced from pronounced concentration-dependent N–H chemical shift variation in 1H NMR and the

• second group of molecules (conformation B). In the crystal lattice, each molecule establishes four intermolecular CO···HN hydrogen bonds. Only the inter-residue carbonyl (oxygen atom labeled O2, Figure 3C) participates in this network, making two hydrogen bonds with two different molecules and different

• such as CDCl3, resonance broadening may also be due to intermolecular association. The chemical shift of donor protons (D–H) involved in intermolecular hydrogen bonds is generally very sensitive to concentration change. A variable concentration 1H NMR study of monomer A and trimer 3 was carried out in

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

• intermolecular mechanism, considered as post-synthesis of new luminescent compounds offers promising applications in sensing and electroluminescence by manipulating the frontier molecular orbital energy levels of organic conjugated materials, simply based on Lewis acid–base chemistry. Keywords: excitons

• multiple molecules [13]. The exciplex contains new excited states through charge transfer between a donor molecule and an acceptor molecule. This provides a simple way to create new luminescence processes through the intermolecular interactions of existing molecules [14]. It has been reported that new

• intermolecular charge transfer. Compared with B(C6H5)3, the exciplex system constructed by BCF exhibited a more pronounced red-shift in the PL spectra and unexpectedly improved EL properties. The fluorescent materials, which can easily interact with Lewis acids and simultaneously exhibit significant chemical and

Thiophene/selenophene-based S-shaped double helicenes: regioselective synthesis and structures

• Mengjie Wang,
• Lanping Dang,
• Wan Xu,
• Zhiying Ma,
• Liuliu Shao,
• Guangxia Wang,
• Chunli Li and
• Hua Wang

Beilstein J. Org. Chem. 2022, 18, 809–817, doi:10.3762/bjoc.18.81

• , and double oxidative photocyclization. The photocyclization was a highly regioselective process. The molecular structures of DH-1 and DH-2 were confirmed by X-ray single-crystal analysis. Multiple intermolecular interactions, such as C–S, C–Se, S–S, S–Se, and Se–Se, were observed in the crystal

• )2-bb-DTT, (TMS)2-bb-DST, and (TMS)2-bb-DSS as starting materials. The synthetic method described in this research not only provides a method for the synthesis of S- shaped double helicenes but also enriches the family of selenophene helicenes. Multiple intermolecular interactions and regular

A trustworthy mechanochemical route to isocyanides

• Francesco Basoccu,
• Federico Cuccu,
• Federico Casti,
• Rita Mocci,
• Claudia Fattuoni and
• Andrea Porcheddu

Beilstein J. Org. Chem. 2022, 18, 732–737, doi:10.3762/bjoc.18.73

• -methylimidazole were carried out, the outcomes were not as good as those already documented with pyridine in the literature. Possible explanations for this phenomenon are either a different electronic distribution between the two heterocycles or the absence of intermolecular interactions caused by the solvent

Direct C–H amination reactions of arenes with N-hydroxyphthalimides catalyzed by cuprous bromide

• Dongming Zhang,
• Bin Lv,
• Pan Gao,
• Xiaodong Jia and
• Yu Yuan

Beilstein J. Org. Chem. 2022, 18, 647–652, doi:10.3762/bjoc.18.65

• (reaction 3) [27]. Herein, we report a method for the construction of aromatic amines via the copper-catalyzed intermolecular radical amination of arenes with N-hydroxyphthalimide (NHPI) under air. Results and Discussion Initially, N-hydroxyphthalimide (NHPI, 2a) was reacted with benzene, catalyzed by CuBr

DDQ in mechanochemical C–N coupling reactions

• Shyamal Kanti Bera,
• Rosalin Bhanja and
• Prasenjit Mal

Beilstein J. Org. Chem. 2022, 18, 639–646, doi:10.3762/bjoc.18.64

• -Dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) is a commonly known oxidant. Herein, we report that DDQ can be used to synthesize 1,2-disubstituted benzimidazoles and quinazolin-4(3H)-ones via the intra- and intermolecular C–N coupling reaction under solvent-free mechanochemical (ball milling) conditions. In

Heteroleptic metallosupramolecular aggregates/complexation for supramolecular catalysis

• Prodip Howlader and
• Michael Schmittel

Beilstein J. Org. Chem. 2022, 18, 597–630, doi:10.3762/bjoc.18.62

• Switchable catalysis due to reversible assembly/disassembly Toggling between intra- and intermolecular complexation in nanoswitches Review Catalysis using heteroleptic discrete supramolecular architectures In its early years, supramolecular chemistry mainly focused on host–guest interactions, primarily on

• . For this purpose, they have chosen the ditopic bisurea “strut” 12 (Figure 3), which generated a 2D discrete molecular triangle 14 in the presence of an equimolar amount of the cis-(tmen)Pd(NO3)2 acceptor 5 [59]. In order to prevent the urea moieties on the triangle to get engaged in intermolecular H

• further options. In particular, the protocol of acid addition and removal (upon base addition) may be elegantly replaced by using a suitable fuel acid thus opening the field of supramolecular catalysis for out-of-equilibrium processing. Toggling between intra- and intermolecular complexation in

A study of the photochemical behavior of terarylenes containing allomaltol and pyrazole fragments

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

Beilstein J. Org. Chem. 2022, 18, 588–596, doi:10.3762/bjoc.18.61

• considered photoprocess. Probably, the DMF molecule forms an intermolecular hydrogen bond with the hydroxy group of the allomaltol fragment leading to complete suppression of the ESIPT process. Finally, AcOH was used as a solvent for the photochemical synthesis of α-hydroxy-1,2-diketone 14a. The starting

Syntheses of novel pyridine-based low-molecular-weight luminogens possessing aggregation-induced emission enhancement (AIEE) properties

• Masayori Hagimori,
• Tatsusada Yoshida,
• Yasuhisa Nishimura,
• Yukiko Ogawa and
• Keitaro Tanaka

Beilstein J. Org. Chem. 2022, 18, 580–587, doi:10.3762/bjoc.18.60

• quenched due to aggregation-caused quenching (ACQ) [10]. Generally, the restriction of intermolecular π–π interactions in highly planar compounds plays a key role in aggregate structures exhibiting fluorescence [5][6][10]. In addition, intramolecular mechanisms, such as intramolecular rotation (RIR

• ΦH2O/ΦEtOH values of 0.07 and 0.12, respectively, which were 7.0 and 15 times higher than those in ethanol (non-aggregated form). Because compounds 4a–e form an A–D–A system, charge disproportionation may affect intermolecular π–π interactions and lead to AIEE. The enhanced fluorescence was almost

• completely quenched by the addition of an 0.1 M HCl solution to solutions of compounds 4a and 4e (Figure 3). This result indicated that the protonation of the secondary amine disrupted the intermolecular π–π interactions or planarity of compounds 4 (Figure 4), and the rigid structure in solution was involved

Unusual highly diastereoselective Rh(II)-catalyzed dimerization of 3-diazo-2-arylidenesuccinimides provides access to a new dibenzazulene scaffold

• Anastasia Vepreva,
• Alexander S. Bunev,
• Andrey Yu. Kudinov,
• Grigory Kantin,
• Mikhail Krasavin and
• Dmitry Dar’in

Beilstein J. Org. Chem. 2022, 18, 533–538, doi:10.3762/bjoc.18.55

• diazocarbonyl compounds [5]. The close spatial arrangement of the conjugate aryl fragment and the diazo group in the DAS molecule favors both intramolecular and intermolecular cyclizations involving the arylidene group. Thus, under catalytic decomposition, DAS containing a 2-pyridyl or 2-hydroxyaryl substituent

• the formation of the corresponding dimers 2 or azines 4 was not observed. Most likely, the introduction of the ortho-substituent disturbed the molecule’s coplanarity, which may have created steric obstacles for the intermolecular process. Rather remarkable was the reaction of DAS 1r containing an

BINOL as a chiral element in mechanically interlocked molecules

• Matthias Krajnc and
• Jochen Niemeyer

Beilstein J. Org. Chem. 2022, 18, 508–523, doi:10.3762/bjoc.18.53

• catalysts (e.g., (S)-49), based on intermolecular interactions that are relevant especially at higher catalyst loadings [61]. Subsequently, our working group reported the synthesis and application of the BINOL-based [2]rotaxanes (S)-56 and (S)-57 [62]. For their synthesis, the phosphoric acid macrocycles (S

Comparative study of thermally activated delayed fluorescent properties of donor–acceptor and donor–acceptor–donor architectures based on phenoxazine and dibenzo[a,j]phenazine

• Saika Izumi,
• Prasannamani Govindharaj,
• Anna Drewniak,
• Paola Zimmermann Crocomo,
• Satoshi Minakata,
• Leonardo Evaristo de Sousa,
• Piotr de Silva,
• Przemyslaw Data and
• Youhei Takeda

Beilstein J. Org. Chem. 2022, 18, 459–468, doi:10.3762/bjoc.18.48

• deposition process. However, when compared with the D–A–D counterpart, the Td of 1 is much lower (by 111 °C) than that of POZ-DBPHZ (453 °C) [17]. These data would support that the increase in the sterically hindered donors in emitting molecule suppress intermolecular contact to enhance the thermal stability

A resorcin[4]arene hexameric capsule as a supramolecular catalyst in elimination and isomerization reactions

• Tommaso Lorenzetto,
• Fabrizio Fabris and
• Alessandro Scarso

Beilstein J. Org. Chem. 2022, 18, 337–349, doi:10.3762/bjoc.18.38

• the active site of the enzyme. Once bound, substrate activation is carried out by specific amino acid side chains that adorn the inner surface of the cavity by means of a combination of covalent and/or weak intermolecular interactions leading to the stabilization of intermediate species and transition

• hexameric capsule 16 acts mimicking enzymes by combination of the activation of substrates by protonation, stabilization of cationic intermediate species with consequent acceleration of its conversion and selective product formation thanks to weak intermolecular interactions between the cationic

A Se···O bonding catalysis approach to the synthesis of calix[4]pyrroles

• Qingzhe Tong,
• Zhiguo Zhao and
• Yao Wang

Beilstein J. Org. Chem. 2022, 18, 325–330, doi:10.3762/bjoc.18.36

• transformations, which play a key factor to modulate the selectivity of these reactions [36][37][38][39][40]. In addition, few examples demonstrated that disubstituted chalcogens could be used as effective catalysts through intermolecular chalcogen bonding interactions [41][42][43][44][45][46][47][48][49

Site-selective reactions mediated by molecular containers

• Rui Wang and
• Yang Yu

Beilstein J. Org. Chem. 2022, 18, 309–324, doi:10.3762/bjoc.18.35

• achieved with just the rhodium catalyst, by which in contrast, the fully hydrogenated product was obtained. Other series of intermolecular comparative experiments also showed the selectivity of the hydrogenation for the sterically accessible alkene over other sites and even in the presence of inherently

Iridium-catalyzed hydroacylation reactions of C1-substituted oxabenzonorbornadienes with salicylaldehyde: an experimental and computational study

• Angel Ho,
• Austin Pounder,
• Krish Valluru,
• Leanne D. Chen and
• William Tam

Beilstein J. Org. Chem. 2022, 18, 251–261, doi:10.3762/bjoc.18.30

• independently studied the rhodium-catalyzed intermolecular hydroacylation reaction of salicylaldehydes with norbornadiene derivatives. It was found that electron-donating moieties at the C1-position were well tolerated in the hydroacylation reaction giving methyl- (15b), ethyl- (15c), and t-Bu- (15d) adducts in

• explanation towards the sole production of the experimentally observed anti-acylated product 15. Although Weller and co-workers have elegantly demonstrated hydride migration, rather than the alternative carbometalation, occurs during rhodium-catalyzed intermolecular alkyne hydroacylation [78], no such

The enzyme mechanism of patchoulol synthase

• Houchao Xu,
• Bernd Goldfuss,
• Gregor Schnakenburg and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2022, 18, 13–24, doi:10.3762/bjoc.18.2

• reactivated by protonation for further cyclisation steps, while previously discussed intra- and intermolecular hydrogen transfers are not supported. Furthermore, the isolation of the new natural product (2S,3S,7S,10R)-guaia-1,11-dien-10-ol from patchouli oil is reported. Keywords: biosynthesis; DFT

• H to J transformation. To re-investigate the suggested intermolecular proton exchange in the biosynthesis of 3 (Scheme 3C) [14], an incubation experiment with the mixed substrates (2-2H)FPP [27] and (15-13C)FPP [24] was performed (Scheme 6D). Their conversion with PTS only resulted in a singlet for

• labelled C15 of 3 in the 13C NMR spectrum, but no upfield-shifted triplet (Figure S28, Supporting Information File 1), demonstrating that the hypothetical intermolecular proton shift does not take place. Instead, an additional incorporation of deuterium into the substrate during synthesis, contaminating

Peptide stapling by late-stage Suzuki–Miyaura cross-coupling

• Hendrik Gruß,
• Rebecca C. Feiner,
• Ridhiwan Mseya,
• David C. Schröder,
• Michał Jewgiński,
• Kristian M. Müller,
• Rafał Latajka,
• Antoine Marion and
• Norbert Sewald

Beilstein J. Org. Chem. 2022, 18, 1–12, doi:10.3762/bjoc.18.1

• studies were initiated with a macrocyclisation between a 7-bromotryptophan and a 4-pinacolatoborono phenylalanine side chain to generate the cyclic peptide P1b (Scheme 2A and B). The intramolecular SMC took place with full consumption of the starting material and without formation of an intermolecular

Iron-catalyzed domino coupling reactions of π-systems

• Austin Pounder and
• William Tam

Beilstein J. Org. Chem. 2021, 17, 2848–2893, doi:10.3762/bjoc.17.196

• of the alkyl radical generating the cross-coupled product cannot be ruled out [57][60]. In 2020, Gutierrez and co-workers developed a Fe-catalyzed intra- and intermolecular difunctionalization of vinyl cyclopropanes 14 with alkyl bromides 13 and aryl Grignard reagents 2 (Scheme 4) [61]. Using

• sterically hindered tertiary alkyl bromides, the authors were able to favor intermolecular radical addition of the generated alkyl radical 17 to the vinylcyclopropane, outcompeting radical rebound to an aryl Fe species. The incipient radical can then undergo ring-opening of the cyclopropane 18. Work by

• -lactones [146]. In 2020, Cai and co-workers reported a three-component intermolecular trifluoromethyl-esterification of activated alkenes 115 with NaOTf and aryl carboxylic acids 178 (Scheme 39) [147]. Notably, the use of NaOTf as a CF3 source, compared to pre-prepared trifluoromethylating agents like

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

• context, Bai and co-workers (2019) developed the direct intermolecular enantioselective C–H amination of N-aryl-2-naphthylamines 92 with azodicarboxylates 93 to prepare N–C atropisomers of nonbiaryl naphthalene-1,2-diamine 94. In the presence of chiral phosphoric acids (CPA 15), the desired product 94 was

Recent advances in organocatalytic asymmetric aza-Michael reactions of amines and amides

• Pratibha Sharma,
• Raakhi Gupta and
• Raj K. Bansal

Beilstein J. Org. Chem. 2021, 17, 2585–2610, doi:10.3762/bjoc.17.173

• intermolecular asymmetric Michael addition of alk-2-enoic acids 68 with O-benzylhydroxylamine (69) giving racemic mixture of the product in poor yield. However, the integrated catalyst having boronic acid functionality in the chiral thiourea molecule gave the desired β-benzyloxyamino acid as the single product

• -quinone methides. Asymmetric intermolecular aza-Michael addition of (E)-3-substituted-2-enoic acid. Asymmetric aza-Michael addition reaction for the synthesis of N-hydroxyaspartic acid derivatives catalyzed by chiral multifunctional thiourea/boronic acid. Intramolecular aza-Michael addition catalyzed by

Cryogels: recent applications in 3D-bioprinting, injectable cryogels, drug delivery, and wound healing

• Luke O. Jones,
• Leah Williams,
• Tasmin Boam,
• Martin Kalmet,
• Chidubem Oguike and
• Fiona L. Hatton

Beilstein J. Org. Chem. 2021, 17, 2553–2569, doi:10.3762/bjoc.17.171

• intermolecular hydrogen bonding changes, leading to variations on how hydrated the cryogel is, triggering a volume phase transition [34][35]. Changes in solubility can be described by the upper critical solution temperature (UCST) and lower critical solution temperatures (LCST). The UCST is the temperature at

Visible-light-mediated copper photocatalysis for organic syntheses

• Yajing Zhang,
• Qian Wang,
• Zongsheng Yan,
• Donglai Ma and
• Yuguang Zheng

Beilstein J. Org. Chem. 2021, 17, 2520–2542, doi:10.3762/bjoc.17.169

• thiocyanate to generate 4-alkyl/aryl-2-aminothiazoles. Mechanistic experiments demonstrated that the photocatalyst formed in situ from Cu(OAc)2 and ammonium thiocyanate promoted the intermolecular cyclization (Scheme 7). 3.2 Difunctionalization of alkenes The 1,2-difunctionalization of alkenes is a versatile

Recent advances in the tandem annulation of 1,3-enynes to functionalized pyridine and pyrrole derivatives

• Yi Liu,
• Puying Luo,
• Yang Fu,
• Tianxin Hao,
• Xuan Liu,
• Qiuping Ding and
• Yiyuan Peng

Beilstein J. Org. Chem. 2021, 17, 2462–2476, doi:10.3762/bjoc.17.163

• pyridine derivatives have been developed through the intramolecular or intermolecular tandem addition annulation/functionalization of alkynes with some N-containing compounds, such as nitriles, oximes, and imines [15][16][17][18][19]. The pyrrole structural motif is also an invaluable five-membered N

• -annulation reaction may undergo a free-radical addition pathway. Firstly, NFSI oxidizes Cu(I) to form bissulfonylamidyl radical 10. Secondly, intermolecular nitrogen free-radical addition to the alkyne provides the vinyl radical 11. Then, there may be two possible pathways. Path a: vinyl radical 11 is

• tandem reaction of 2-trifluoromethyl-1,3-enynes 36 with primary amines, affording various trifluoromethyl-substituted 3-pyrrolines [56]. Subsequently, they also developed a novel route for the synthesis of halogenated trifluoromethylated pyrroles 37 and 38 by sequential intermolecular hydroamination