Mechanochemical green synthesis of hyper-crosslinked cyclodextrin polymers

• Alberto Rubin Pedrazzo,
• Fabrizio Caldera,
• Marco Zanetti,
• Silvia Lucia Appleton,
• Nilesh Kumar Dhakar and
• Francesco Trotta

Beilstein J. Org. Chem. 2020, 16, 1554–1563, doi:10.3762/bjoc.16.127

• instance, dye-modified cyclodextrins and CD derivatives have found wide use for the preparation of chemical sensors [24][25]. As CDs and consequently CD nanosponges can be easily coupled with fluorophores, they could find applications in the pharmacological area, for example, as biological markers, in

Heterogeneous photocatalysis in flow chemical reactors

• Christopher G. Thomson,
• Ai-Lan Lee and
• Filipe Vilela

Beilstein J. Org. Chem. 2020, 16, 1495–1549, doi:10.3762/bjoc.16.125

Highly selective Diels–Alder and Heck arylation reactions in a divergent synthesis of isoindolo- and pyrrolo-fused polycyclic indoles from 2-formylpyrrole

• Carlos H. Escalante,
• Eder I. Martínez-Mora,
• Carlos Espinoza-Hicks,
• Alejandro A. Camacho-Dávila,
• Fernando R. Ramos-Morales,
• Francisco Delgado and
• Joaquín Tamariz

Beilstein J. Org. Chem. 2020, 16, 1320–1334, doi:10.3762/bjoc.16.113

• TSs were large enough (>3 kcal/mol) to find an endo/exo diastereoisomeric ratio greater than 99:1, which is in agreement with the observed experimental results. For the reaction with 8b (R2 = CN) the calculated endo/exo ratio (99.4:0.6) and the experimental one (76:24) did not concur. However, the

Oxime radicals: generation, properties and application in organic synthesis

• Igor B. Krylov,
• Stanislav A. Paveliev,
• Alexander S. Budnikov and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2020, 16, 1234–1276, doi:10.3762/bjoc.16.107

• oximes, a widely available and fundamental class of organic compounds. However, oxime radicals almost did not find synthetic use until recently, probably due to the low stability of the majority of representatives of this type of radicals. The applications of oxime radicals in organic synthesis have

• -withdrawing groups (such as carbonyl and CF3). Оxime radicals did not find wide application in organic synthesis and were mainly the subject of fundamental physicochemical studies for a long time since their discovery in 1964. The possible reason is the low stability of the majority of iminoxyl radicals. Only

Anthelmintic drug discovery: target identification, screening methods and the role of open science

• Frederick A. Partridge,
• Ruth Forman,
• Carole J. R. Bataille,
• Graham M. Wynne,
• Marina Nick,
• Angela J. Russell,
• Kathryn J. Else and
• David B. Sattelle

Beilstein J. Org. Chem. 2020, 16, 1203–1224, doi:10.3762/bjoc.16.105

Activated carbon as catalyst support: precursors, preparation, modification and characterization

• Melanie Iwanow,
• Tobias Gärtner,
• Volker Sieber and
• Burkhard König

Beilstein J. Org. Chem. 2020, 16, 1188–1202, doi:10.3762/bjoc.16.104

• . They found that both conditions influence strongly the adsorption of phenol and methylene blue on the nutshell-based carbons. It is essential to find the optimum activation time, since shorter treatments (6 h) do not lead to a porous structure and longer activation times (24 h) causes a collapsing of

A simple and easy to perform synthetic route to functionalized thienyl bicyclo[3.2.1]octadienes

• Dragana Vuk,
• Irena Škorić,
• Valentina Milašinović,
• Krešimir Molčanov and
• Željko Marinić

Beilstein J. Org. Chem. 2020, 16, 1092–1099, doi:10.3762/bjoc.16.96

• structure the prepared compounds 1–12 are candidates for biological assays. The novel styryl derivatives 3–7 and 12 could also find application in further research for functionalization of the bicyclo[3.2.1.]octadiene core. Known biologically active bicyclo[3.2.1]octenes/octadienes. Previously prepared

Synthesis of novel multifunctional carbazole-based molecules and their thermal, electrochemical and optical properties

• Nuray Altinolcek,
• Ahmet Battal,
• Mustafa Tavasli,
• William J. Peveler,
• Holly A. Yu and
• Peter J. Skabara

Beilstein J. Org. Chem. 2020, 16, 1066–1074, doi:10.3762/bjoc.16.93

• [21][22][23]. Research continues on carbazole derivatives to find new materials with novel properties. It is therefore essential that one should design a molecule that has multifunctional usage in many different areas of technology [24]. Since carbazole is a relatively inexpensive material with unique

Pd-catalyzed asymmetric Suzuki–Miyaura coupling reactions for the synthesis of chiral biaryl compounds with a large steric substituent at the 2-position

• Yongsu Li,
• Bendu Pan,
• Xuefeng He,
• Wang Xia,
• Yaqi Zhang,
• Hao Liang,
• Chitreddy V. Subba Reddy,
• Rihui Cao and
• Liqin Qiu

Beilstein J. Org. Chem. 2020, 16, 966–973, doi:10.3762/bjoc.16.85

• (Table 1, entries 2–7). The results show that the higher the steric hindrance of the ligand, the better the yield and enantioselectivity. In order to find out whether the 1’-substituent of the ligand has any influence on the reaction result, we replaced the methoxy group (L3) with an ethoxy group (L8

A method to determine the correct photocatalyst concentration for photooxidation reactions conducted in continuous flow reactors

• Clemens R. Horn and
• Sylvain Gremetz

Beilstein J. Org. Chem. 2020, 16, 871–879, doi:10.3762/bjoc.16.78

• Figure 11. About the same absolute conversion was obtained for similar liquid flow rates independent from the residence time. Conclusion We developed a reliable, quick, and simple approach to find the appropriate starting concentration of a photocatalyst for a photooxidation reaction in a flow reactor

Aldehydes as powerful initiators for photochemical transformations

• Maria A. Theodoropoulou,
• Nikolaos F. Nikitas and
• Christoforos G. Kokotos

Beilstein J. Org. Chem. 2020, 16, 833–857, doi:10.3762/bjoc.16.76

• photophysical properties of aldehydes, in 1968, Yang and co-workers investigated the mechanism of energy transfer from the triplet states of carbonyl compounds to simple olefins [15][16]. In more detail, in order to find out if the excitation energy of the triplet state of the carbonyl compounds could be

• (157) to find that 4-cyanobenzaldehyde (53) again proved to be the best photoinitiator in terms of the yield and selectivity, affording the desired carbonylated product 158 in a selectivity ratio of >20:1 (Scheme 37). Primary alkyl aldehydes, aldehydes containing branched alkyl chains or cyclic

Preparation of 2-phospholene oxides by the isomerization of 3-phospholene oxides

• Péter Bagi,
• Réka Herbay,
• Nikolett Péczka,
• Zoltán Mucsi,
• István Timári and
• György Keglevich

Beilstein J. Org. Chem. 2020, 16, 818–832, doi:10.3762/bjoc.16.75

• wished to find another isomerization pathways leading to the corresponding 2-phospholene oxides 4, which does not require inert reaction conditions. Literature data indicated that such izomerizations may take place in the presence of acids [59][62][64]. 1-Phenyl-3-methyl-3-phospholene oxide (1a) was

Reaction of indoles with aromatic fluoromethyl ketones: an efficient synthesis of trifluoromethyl(indolyl)phenylmethanols using K₂CO₃/n-Bu₄PBr in water

• Thanigaimalai Pillaiyar,
• Masoud Sedaghati and
• Gregor Schnakenburg

Beilstein J. Org. Chem. 2020, 16, 778–790, doi:10.3762/bjoc.16.71

• triphosphate (Table 1, entry 12; 76%) did not improve the yield. These results suggest that K2CO3 is the best catalyst for the reaction among the bases investigated. To find the best catalytic system, other quaternary salts were invested in the reaction. When tetrabutylammonium chloride (TBAC) or

• interact with the base, thereby initiating the reaction. To find the importance of electrophilicity of ketones, different enolizable and nonenolizable ketones were screened with the reaction of 5-methoxyindole (1a). The enolizable ketones 2j–l failed to provide the products (see Table 2). Similarly

Rhodium-catalyzed reductive carbonylation of aryl iodides to arylaldehydes with syngas

• Zhenghui Liu,
• Peng Wang,
• Zhenzhong Yan,
• Suqing Chen,
• Dongkun Yu,
• Xinhui Zhao and
• Tiancheng Mu

Beilstein J. Org. Chem. 2020, 16, 645–656, doi:10.3762/bjoc.16.61

• experimental parameters. We explored the optimal ratio of Rh salt and PPh3 ligand, substrate scope, carbonyl source and hydrogen source, and the reaction mechanism. Particularly, a scaled-up experiment indicated that the catalytic method could find valuable applications in industrial productions. The low gas

Asymmetric synthesis of CF₂-functionalized aziridines by combined strong Brønsted acid catalysis

• Xing-Fa Tan,
• Fa-Guang Zhang and
• Jun-An Ma

Beilstein J. Org. Chem. 2020, 16, 638–644, doi:10.3762/bjoc.16.60

• the chiral additive in combination with 2-carboxyphenylboronic acid (COOH-BA) in the model reaction (Table 1, entries 3–8). We were pleased to find that CDSI-4 gave the most promising result in terms of both yield and enantioselectivity (64% isolated yield with 73% ee, Table 1, entry 6). An

Direct borylation of terrylene and quaterrylene

• Haruka Kano,
• Keiji Uehara,
• Kyohei Matsuo,
• Hironobu Hayashi,
• Hiroko Yamada and
• Naoki Aratani

Beilstein J. Org. Chem. 2020, 16, 621–627, doi:10.3762/bjoc.16.58

• to be metallic with a small bandgap [28][29][30], and the narrowest AGNR is polyrylene (5-AGNR, p = 1) [31][32]. Many potential applications await techniques to prepare large scale quantities of functionalized oligorylenes. We believe that our approach opens fruitful oligorylene researches that find

Copper-catalyzed remote C–H arylation of polycyclic aromatic hydrocarbons (PAHs)

• Anping Luo,
• Min Zhang,
• Zhangyi Fu,
• Jingbo Lan,
• Di Wu and
• Jingsong You

Beilstein J. Org. Chem. 2020, 16, 530–536, doi:10.3762/bjoc.16.49

• optimal conditions in hand, we first examined the scope of aryliodonium salts. We were very pleased to find that a range of aryliodonium salts could be employed as arylating reagents, affording 7-arylated 1-naphthamides (3a–q) in moderate to excellent yields (Scheme 2). This protocol tolerated a wide

Visible-light-induced addition of carboxymethanide to styrene from monochloroacetic acid

• Kaj M. van Vliet,
• Nicole S. van Leeuwen,
• Albert M. Brouwer and
• Bas de Bruin

Beilstein J. Org. Chem. 2020, 16, 398–408, doi:10.3762/bjoc.16.38

• glycine and diethyl malonate, are based on nucleophilic substitution of the chlorine [6][7][8][9][10]. In an attempt to find new synthetic applications of monochloroacetic acid we turned our attention to photoredox catalysis. We were inspired by the rebirth of visible light photoredox catalysis, induced

p-Pyridinyl oxime carbamates: synthesis, DNA binding, DNA photocleaving activity and theoretical photodegradation studies

• Panagiotis S. Gritzapis,
• Panayiotis C. Varras,
• Nikolaos-Panagiotis Andreou,
• Katerina R. Katsani,
• Konstantinos Dafnopoulos,
• George Psomas,
• Zisis V. Peitsinis,
• Alexandros E. Koumbis and
• Konstantina C. Fylaktakidou

Beilstein J. Org. Chem. 2020, 16, 337–350, doi:10.3762/bjoc.16.33

• examine the transitions (S0 → T1 and S0 → S1) we find that there are major differences in the nature of the transitions. In particular, for the transition S0 → T1 the excitation is localized on the pyridine moiety for 12, while for 11 it is localized on the p-nitrophenyl group. As far as the S0 → S1

• chemical reaction below (Scheme 3). The activation free energy for the decarboxylation reaction is only 1.09 kcal/mol and by using Equation 4 (see theoretical calculations section) we find a rate constant kr = 9.87∙1011 s−1, characterizing the reaction as an ultrafast one, with a corresponding life-time of

Synthesis and circularly polarized luminescence properties of BINOL-derived bisbenzofuro[2,3-b:3’,2’-e]pyridines (BBZFPys)

• Ryo Takishima,
• Yuji Nishii,
• Tomoaki Hinoue,
• Yoshitane Imai and
• Masahiro Miura

Beilstein J. Org. Chem. 2020, 16, 325–336, doi:10.3762/bjoc.16.32

• -state structures were investigated by X-ray diffraction analysis to find well-ordered intermolecular stacking structures within the crystals. Experimental General All manipulations were performed under N2 using standard Schlenk techniques unless otherwise noted. DMF was dried and deoxygenated by a Glass

Recent developments in photoredox-catalyzed remote ortho and para C–H bond functionalizations

• Rafia Siddiqui and
• Rashid Ali

Beilstein J. Org. Chem. 2020, 16, 248–280, doi:10.3762/bjoc.16.26

• selectivity, sustainability, and environmentally friendly bond constructions. C–H fluoroalkylation of arenes Fluoroalkylations in earlier reported methods required prefunctionalization of arenes, directing groups, etc. [175][176][177][178][179]. In this context, researchers were trying to find alternatives to

Efficient method for propargylation of aldehydes promoted by allenylboron compounds under microwave irradiation

• Jucleiton J. R. Freitas,
• Queila P. S. B. Freitas,
• Silvia R. C. P. Andrade,
• Juliano C. R. Freitas,
• Roberta A. Oliveira and
• Paulo H. Menezes

Beilstein J. Org. Chem. 2020, 16, 168–174, doi:10.3762/bjoc.16.19

• only low conversion (Table 4, entry 1). In order to find an appropriate and suitable solvent that could be used in small amounts to promote the reaction different solvents were screened and the best result was observed when a small amount of acetone was used, where 2a was obtained in 92% yield as a

Synthesis, liquid crystalline behaviour and structure–property relationships of 1,3-bis(5-substituted-1,3,4-oxadiazol-2-yl)benzenes

• Afef Mabrouki,
• Malek Fouzai,
• Armand Soldera,
• Abdelkader Kriaa and
• Ahmed Hedhli

Beilstein J. Org. Chem. 2020, 16, 149–158, doi:10.3762/bjoc.16.17

• relative to the other heteroatoms, suggesting that Oxd 1 is more polar than Oxd 2. Such a difference in polarity was corroborated by the direction of the dipole moment of RC (Table 5). Therefore, it is not surprising to find the molecular electron-deficient center so far from the axis of the molecule in

Understanding the role of active site residues in CotB2 catalysis using a cluster model

• Keren Raz,
• Ronja Driller,
• Thomas Brück,
• Bernhard Loll and
• Dan T. Major

Beilstein J. Org. Chem. 2020, 16, 50–59, doi:10.3762/bjoc.16.7

• ions were fixed throughout the reaction progress. The entire cage system was treated using the above-mentioned DFT method. In order to find the TS structures, complete TS optimizations using the keywords "QST2", "QST3", and “Modredundant” were performed. A main limitation of the current cluster

Microwave-assisted synthesis of 2-substituted 4,5,6,7-tetrahydro-1,3-thiazepines from 4-aminobutanol

• María C. Mollo,
• Natalia B. Kilimciler,
• Juan A. Bisceglia and
• Liliana R. Orelli

Beilstein J. Org. Chem. 2020, 16, 32–38, doi:10.3762/bjoc.16.5

• applications as antibiotics [1], antiproliferative agents [2], anti-inflammatories [3] and antithrombotics [4]. They are also found in many bioactive natural products [5][6][7][8], some of which display anti-HIV-1 [9] and antimitotic activities [10], among others. Thiazolines also find use in organic synthesis

• (trimethylsilyl polyphosphate) are powerful and versatile dehydrating agents that find many applications in organic synthesis [33][34][35][36][37][38][39][40][41][42]. Their preparation is operationally simple and requires readily available and inexpensive starting materials. In addition, they are stable, non