On drug discovery against infectious diseases and academic medicinal chemistry contributions

• Yves L. Janin

Beilstein J. Org. Chem. 2022, 18, 1355–1378, doi:10.3762/bjoc.18.141

• survey on the efficiency of various programs is also worth consulting as it appears that close to half the docking solutions provided in the context of COVID-19 research for antivirals were useless to guide medicinal chemistry efforts [77]. A very recent illustration of the difference of actual results

Cyclodextrin-based Schiff base pro-fragrances: Synthesis and release studies

• Attila Palágyi,
• Jindřich Jindřich,
• Juraj Dian and
• Sophie Fourmentin

Beilstein J. Org. Chem. 2022, 18, 1346–1354, doi:10.3762/bjoc.18.140

• flavor control; it could be used to improve the stabilization, quality, efficiency and persistence of repellents, disinfectants, perfumes, laundry detergents and flavoring agents [15][16]. Another strategy to prolong the longevity of the fragrance and, as an additional benefit, to increase the stability

B–N/B–H Transborylation: borane-catalysed nitrile hydroboration

• Filip Meger,
• Alexander C. W. Kwok,
• Franziska Gilch,
• Dominic R. Willcox,
• Alex J. Hendy,
• Kieran Nicholson,
• Andrew D. Bage,
• Thomas Langer,
• Thomas A. Hunt and
• Stephen P. Thomas

Beilstein J. Org. Chem. 2022, 18, 1332–1337, doi:10.3762/bjoc.18.138

• adjusted to maximise efficiency for yield or chemoselectivity. Reaction of the turnover reagent, HBpin, in the absence of catalyst gave no observable reduction (see Supporting Information File 1). The optimised conditions were applied to a substrate scope, where the hydroboration products were converted in

• further derivatisation. 2-Chlorobenzylamine hydrochloride, a precursor to the herbicide cumyluron, was isolated in good yield (1g, 65%) [38]. Additionally, fluoro-substituted nitriles were also reduced with good efficiency (1m, 62%). Both electron-withdrawing (1n, 95%) and electron-donating (1o, 87%, 1p

Ionic multiresonant thermally activated delayed fluorescence emitters for light emitting electrochemical cells

• Merve Karaman,
• Abhishek Kumar Gupta,
• Subeesh Madayanad Suresh,
• Tomas Matulaitis,
• Lorenzo Mardegan,
• Daniel Tordera,
• Henk J. Bolink,
• Sen Wu,
• Stuart Warriner,
• Ifor D. Samuel and
• Eli Zysman-Colman

Beilstein J. Org. Chem. 2022, 18, 1311–1321, doi:10.3762/bjoc.18.136

• in organic light-emitting diodes (OLEDs), relatively little attention has been devoted to the design of ionic small molecule (SM) [13] organic emitters for LEECs. The majority of the reported SM emitters for LEECs are fluorescent in nature and so the internal quantum efficiency (IQE) of the device is

• TADF emitter 2CzPN with imidazolium groups [16][17] (Figure 1a). The LEEC devices showed a maximum external quantum efficiency (EQEmax) of 0.39%, a maximum brightness (Bmax) of 13 cd m−2, and a peak electroluminescence (λEL) at 538 nm. The device performance suffered when the emissive layer was doped

• the non-doped device, at 2.0% demonstrated 100% exciton utilization efficiency in the device and efficient energy transfer from the host to the guest cyanine emitter. Deep blue emission in LEECs is challenging. We also reported a blue-emitting LEEC employing a cationic sulfone-based donor–acceptor

Polymer and small molecule mechanochemistry: closer than ever

• José G. Hernández

Beilstein J. Org. Chem. 2022, 18, 1225–1235, doi:10.3762/bjoc.18.128

• glycosidic bonds [47]. In the same work, Kobayashi, Fukuoka, and co-workers concluded that “if a new mechanical method [different from ball milling] is developed to apply tensile forces to samples selectively and efficiently, it will probably improve the reaction efficiency” [47]. Along these lines, ring-and

Thermally activated delayed fluorescence (TADF) emitters: sensing and boosting spin-flipping by aggregation

• Ashish Kumar Mazumdar,
• Gyana Prakash Nanda,
• Nisha Yadav,
• Upasana Deori,
• Upasha Acharyya,
• Bahadur Sk and
• Pachaiyappan Rajamalli

Beilstein J. Org. Chem. 2022, 18, 1177–1187, doi:10.3762/bjoc.18.122

• –triplet energy gap (ΔEST) [16][17]. The low ΔEST facilitates the exciton upconversion through reverse intersystem crossing (RISC) [2], which is commonly known as thermally activated delayed fluorescence (TADF) [16]. Theoretically, this has up to 100% internal quantum efficiency and could replace heavy

Heterogeneous metallaphotoredox catalysis in a continuous-flow packed-bed reactor

• Wei-Hsin Hsu,
• Susanne Reischauer,
• Peter H. Seeberger,
• Bartholomäus Pieber and
• Dario Cambié

Beilstein J. Org. Chem. 2022, 18, 1123–1130, doi:10.3762/bjoc.18.115

• after chromatography might still be too high for use as API. If the remaining nickel content becomes an issue, a column packed with an immobilized scavenger could be used to further reduce the Ni content in the final product [39]. Reactor optimization Flow maldistribution and poor mixing efficiency in

• efficiency of the nickel cycle in metallaphotoredox reactions. It is therefore not surprising that a larger acceleration of the reaction kinetics in flow versus batch was observed for the C–O coupling as opposed to the C–S coupling. Conclusion In summary, we developed a packed-bed reactor for

A Streptomyces P450 enzyme dimerizes isoflavones from plants

• Run-Zhou Liu,
• Shanchong Chen and
• Lihan Zhang

Beilstein J. Org. Chem. 2022, 18, 1107–1115, doi:10.3762/bjoc.18.113

• , Supporting Information File 1) but not for 13–17, suggesting that CYP158C1 is also compatible with compounds with flavone scaffold. Apart from flavonoids, this enzyme also dimerized umbelliferone (18), a substrate of the fungal P450 KtnC [14][18], and RVT with relatively low efficiency (Figures S19 and S20

• also catalyze isoflavone dimerization, the above results indicated that CYP158C1 dimerizes isoflavones and several plant-derived aromatic polyketides, albeit with low catalytic efficiency. Future optimization of the reductase partner or reaction conditions may be required to improve the enzyme activity

Synthesis of N-phenyl- and N-thiazolyl-1H-indazoles by copper-catalyzed intramolecular N-arylation of ortho-chlorinated arylhydrazones

• Yara Cristina Marchioro Barbosa,
• Guilherme Caneppele Paveglio,
• Claudio Martin Pereira de Pereira,
• Sidnei Moura,
• Cristiane Storck Schwalm,
• Gleison Antonio Casagrande and
• Lucas Pizzuti

Beilstein J. Org. Chem. 2022, 18, 1079–1087, doi:10.3762/bjoc.18.110

• ligand (Table 1, entry 22), but the product could not be detected by TLC analysis. In order to compare the efficiency of the optimized conditions with the one-pot approach, a reaction was carried out starting from o-chlorobenzaldehyde and phenylhydrazine under the conditions shown in Table 1, entry 3

Electrochemical formal homocoupling of sec-alcohols

• Kosuke Yamamoto,
• Kazuhisa Arita,
• Masashi Shiota,
• Masami Kuriyama and
• Osamu Onomura

Beilstein J. Org. Chem. 2022, 18, 1062–1069, doi:10.3762/bjoc.18.108

• effect of acidic and basic additives on the reaction outcome. While the use of Mg(OTf)2, HCO2H, or 2,6-lutidine resulted in reduced reaction efficiency, imidazole exhibited the positive effect on the product yield, providing 2a in 72% yield (Table 1, entries 8–11). Addition of H2O was crucial to obtain

Electrochemical hydrogenation of enones using a proton-exchange membrane reactor: selectivity and utility

• Koichi Mitsudo,
• Haruka Inoue,
• Yuta Niki,
• Eisuke Sato and
• Seiji Suga

Beilstein J. Org. Chem. 2022, 18, 1055–1061, doi:10.3762/bjoc.18.107

• −1, 2a and 3a were obtained in a yield of 3% (current efficiency 66%) and 0.57% (current efficiency 5.7%), respectively (Table 1, entry 2). While 2a was obtained with moderate current efficiency, the yield was far from satisfactory. Therefore, electroreduction with a higher current density was

• conversion of 1a decreased to 82% with a current of 50 mA⋅cm−1, but 2a was obtained in 64% yield with a similar current efficiency (64%). When the reaction was performed in cyclopentyl methyl ether (CPME) as a solvent, the yield of 2a decreased to 54%, and 3a was obtained in 11% yield (Table 2, entry 4

• was the best catalyst for the selective synthesis of 2a, and Ir catalyst should be suitable for the formation of 3a, regarding the current efficiency and selectivity (Table 3, entry 4). We also observed reaction profiles of the hydrogenation of 1a with the use of a Pd/C and Ir/C cathode catalyst

Automated grindstone chemistry: a simple and facile way for PEG-assisted stoichiometry-controlled halogenation of phenols and anilines using N-halosuccinimides

• Dharmendra Das,
• Akhil A. Bhosle,
• Amrita Chatterjee and
• Mainak Banerjee

Beilstein J. Org. Chem. 2022, 18, 999–1008, doi:10.3762/bjoc.18.100

• ortho- and para-positions. The gram-scale reaction shows similar efficiency like smaller batches indicating easy scale-up of this protocol. The method is environmentally friendly and cost-effective having key attributes like simple instrumentation, no aqueous workup, short reaction time, and mild

Molecular diversity of the base-promoted reaction of phenacylmalononitriles with dialkyl but-2-ynedioates

• Hui Zheng,
• Ying Han,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2022, 18, 991–998, doi:10.3762/bjoc.18.99

• ][4][5], because it contains one carbonyl group, two cyano groups, and an activated methylene unit. Phenacylmalononitrile exhibits versatile reactivity, high synthetic efficiency and molecular diversity and has been widely employed in many synthetic reactions [6][7][8][9][10]. On the other hand

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

• example, ITIC (10), is shown in Figure 4. ITIC [17], in combination with polymer 11, achieved a power conversion efficiency (PCE) of 6.8%, which was the best value for NFA organic solar cells at the time of publication. Fluorination of ITIC, obtaining IT-4F (12), shown in Figure 5, reduced ELUMO. Combined

Efficient production of clerodane and ent-kaurane diterpenes through truncated artificial pathways in Escherichia coli

• Fang-Ru Li,
• Xiaoxu Lin,
• Qian Yang,
• Ning-Hua Tan and
• Liao-Bin Dong

Beilstein J. Org. Chem. 2022, 18, 881–888, doi:10.3762/bjoc.18.89

• overexpression in E. coli [19]. Isopentenyl diphosphate isomerase (IDI) from E. coli, which balances IPP and DMAPP in vivo, was also included in our construct. To initially test the efficiency of this two-step artificial pathway, we constructed strains DL10001 (phoN, ipk and idi plus the lycopene-producing genes

Synthesis of novel alkynyl imidazopyridinyl selenides: copper-catalyzed tandem selenation of selenium with 2-arylimidazo[1,2-a]pyridines and terminal alkynes

• Mio Matsumura,
• Kaho Tsukada,
• Kiwa Sugimoto,
• Yuki Murata and
• Shuji Yasuike

Beilstein J. Org. Chem. 2022, 18, 863–871, doi:10.3762/bjoc.18.87

• torsion angle of 10.28°. 2-Phenylimidazo[1,2-a]pyridine moieties of neighboring molecules were arranged into slipped-parallel π-stacks with head-to-tail or head-to-head orientations. The distances between parallel mean planes were 3.427 and 3.428 Å (Figure 2b). To demonstrate the efficiency and to broaden

Palladium-catalyzed solid-state borylation of aryl halides using mechanochemistry

• Koji Kubota,
• Emiru Baba,
• Tamae Seo,
• Tatsuo Ishiyama and
• Hajime Ito

Beilstein J. Org. Chem. 2022, 18, 855–862, doi:10.3762/bjoc.18.86

• amount of H2O added was important for the efficiency of the reaction. Decreasing the amount of H2O to 40 μL led to a lower yield of 3a (68%; Table 1, entry 9). The reaction without H2O afforded 3a in only 8% yield (Table 1, entry 10). Finally, we investigated the effect of the reaction temperature. The

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

• (2.0 equiv), THF (0.2 M), −10 °C, from 30 min to 2 h; iv) N-Boc-N-methylhydrazine (3.0 equiv), H2O/MeOH 1:1 (1.25 M), 60 °C, overnight. Evaluation of the efficiency of mixed anhydride methods by coupling of 1a and 1c. (3 + 3) segment coupling of trimers 3-OH onto trimer hydrazine 3a. Structures, purity

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

• ; fluorescence; Lewis acid; Lewis base; post-synthesis; Introduction Organic light emitting diodes (OLEDs) show great potential to dominate the next generation of flat-panel displays and efficient light sources attributed to the advantages of self-illumination, high efficiency, wide color gamut, and flexibility

• are fluorescent compounds. Based on the spin statistics, the fluorescent emitters can only use singlet excitons for light generation [5]. In contrast, phosphorescent materials based on metal complexes could achieve a high internal quantum efficiency (IQE) up to 100% through intersystem crossing (ISC

• quantum efficiency of ≈6.2%, surpassing the upper limit (ca. 5%) of the conventional fluorescence devices. Strength of Lewis acid–base interactions The energy levels of Lewis acid–base adducts are sensitive to the strength of the Lewis acids and bases. In 2002, Monkman et al. found that the degree of the

Inductive heating and flow chemistry – a perfect synergy of emerging enabling technologies

• Conrad Kuhwald,
• Sibel Türkhan and
• Andreas Kirschning

Beilstein J. Org. Chem. 2022, 18, 688–706, doi:10.3762/bjoc.18.70

• applications under flow conditions 2.1 General remarks Energy efficiency is one of the most important cost factors in industrial processes, especially for high temperature reactions in fixed-bed reactors. In general, conductive particles or (superpara)magnetic nanoparticles are suitable as fixed-bed materials

Rapid gas–liquid reaction in flow. Continuous synthesis and production of cyclohexene oxide

• Kyoko Mandai,
• Tetsuya Yamamoto,
• Hiroki Mandai and
• Aiichiro Nagaki

Beilstein J. Org. Chem. 2022, 18, 660–668, doi:10.3762/bjoc.18.67

• with good efficiency should be pursued either by pressurizing the reaction system filled with gas using an autoclave or by introducing gas into the reaction mixture with bubbling [1]. Thinking about the implementation of gas–liquid reactions, especially at the industrial manufacturing level, the

• the reaction with good efficiency [11][12]. The continuous flow technology has brought a dramatic change and new aspects in organic synthesis [13][14][15][16][17][18][19][20][21][22][23] and has been noticed to provide significant improvement in gas–liquid reactions [24][25]. Thus, we envisioned that

• such a technology should make the gas–liquid-type epoxidation of cyclohexene using air as a green gaseous reagent faster with good efficiency to synthesize important organic compounds. Previous reports on reactions in a flow system using air as a green reactant [26][27] and epoxidations in a flow

Cholyl 1,3,4-oxadiazole hybrid compounds: design, synthesis and antimicrobial assessment

• Anas J. Rasras,
• Mohamed El-Naggar,
• Nesreen A. Safwat and
• Raed A. Al-Qawasmeh

Beilstein J. Org. Chem. 2022, 18, 631–638, doi:10.3762/bjoc.18.63

• screening conditions (Table 1). Interestingly, compounds 4c, 4d, 4g, 4i, 4j, 4l, 4n, 4o, 4p, 4q, 4r, 4s, and 4t exhibited broad spectrum antibacterial and antifungal activities, showing their variable inhibitory activities against multiple microorganisms. The antimicrobial efficiency of the tested compounds

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

• state of the second click reaction, leads to an astounding synthetic efficiency, although there is a major distance mismatch between the copper(I) ions in [FeCu2(104)2]4+ and two triazole units of the rotaxane. For instance, the system [FeCu2(104)2]4+ (dCu–Cu = 34 Å) afforded the formation of both 109a

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

• -concentration solutions, and their emission efficiency, chromogenic properties, and light sensitivity decrease rapidly [5][6]. In recent years, contrary to conventional fluorescent compounds, aggregation-induced emission enhancement (AIEE)-based compounds that exhibit strong fluorescence in aggregate structures

Substituent effect on TADF properties of 2-modified 4,6-bis(3,6-di-tert-butyl-9-carbazolyl)-5-methylpyrimidines

• Irina Fiodorova,
• Tomas Serevičius,
• Rokas Skaisgiris,
• Saulius Juršėnas and
• Sigitas Tumkevicius

Beilstein J. Org. Chem. 2022, 18, 497–507, doi:10.3762/bjoc.18.52

• such as triazine, diazines or aromatics containing cyano and sulfone groups are popular acceptor units for the construction of highly efficient TADF emitters [8][9][10][11]. Pyrimidine (1,3-diazine) owing to its aromaticity, significant π-deficiency, strong electron affinity, high luminous efficiency

• easily minimized, enabling rather efficient TADF. We have shown that electron-withdrawing substituents connected directly to the pyrimidine unit have a larger impact on TADF efficiency in comparison with those attached through a phenylene bridge. The largest delayed fluorescence quantum yield, ranging