Machine learning-guided strategies for reaction conditions design and optimization

• Lung-Yi Chen and
• Yi-Pei Li

Beilstein J. Org. Chem. 2024, 20, 2476–2492, doi:10.3762/bjoc.20.212

• density estimators to efficiently explore parameter space. This method updates prior probability distributions with new experimental results and optimizes the reaction conditions by focusing on regions of the parameter space predicted to improve objectives. The power of BO lies in its ability to balance

HFIP as a versatile solvent in resorcin[n]arene synthesis

• Hormoz Khosravi,
• Valeria Stevens and
• Raúl Hernández Sánchez

Beilstein J. Org. Chem. 2024, 20, 2469–2475, doi:10.3762/bjoc.20.211

• set at 50% probability level. Resorcin[n]arene synthesis. Scope of resorcin[n]arene synthesis using HFIP. aAll reactions were performed with resorcinol (1.0 mmol), aldehyde (1.0 mmol), and HCl (30 mol %) in HFIP (5 mL) at room temperature, and the yields of the reactions are given as isolated yields

Synthesis and conformational analysis of pyran inter-halide analogues of ᴅ-talose

• Olivier Lessard,
• Mathilde Grosset-Magagne,
• Paul A. Johnson and
• Denis Giguère

Beilstein J. Org. Chem. 2024, 20, 2442–2454, doi:10.3762/bjoc.20.208

• , 17, and α-ᴅ-talose 18. ORTEP diagram showing 50% thermal ellipsoid probability (except for 18): carbon (gray), oxygen (red), fluorine (green), chlorine (orange), bromine (dark red), iodine (purple), and hydrogen (white). Packing arrangement of compound compound 15; a) View down the b axis; b

• ) proposed intermolecular interactions involving halogens. ORTEP diagram showing 50% thermal ellipsoid probability: carbon (gray), oxygen (red), fluorine (green), iodine (purple), and hydrogen (white). Synthesis of halogenated talopyranose analogues 13–15, and 17 that include a 2,3-cis, 3,4-cis relationship

Evaluating the halogen bonding strength of a iodoloisoxazolium(III) salt

• Dominik L. Reinhard,
• Anna Schmidt,
• Marc Sons,
• Julian Wolf,
• Elric Engelage and
• Stefan M. Huber

Beilstein J. Org. Chem. 2024, 20, 2401–2407, doi:10.3762/bjoc.20.204

• ). Halogen bonding dimer found in the crystal structure of 7Br. Ellipsoids are shown at 50% probability (carbon: grey, nitrogen: blue, oxygen: red, bromine: orange, iodine: purple) and hydrogen atoms are shown in standard ball-and-stick model (white). Halogen and hydrogen bonding is indicated dashed. 1H NMR

Synthesis, electrochemical properties, and antioxidant activity of sterically hindered catechols with 1,3,4-oxadiazole, 1,2,4-triazole, thiazole or pyridine fragments

• Daria A. Burmistrova,
• Andrey Galustyan,
• Nadezhda P. Pomortseva,
• Kristina D. Pashaeva,
• Maxim V. Arsenyev,
• Oleg P. Demidov,
• Mikhail A. Kiskin,
• Andrey I. Poddel’sky,
• Nadezhda T. Berberova and
• Ivan V. Smolyaninov

Beilstein J. Org. Chem. 2024, 20, 2378–2391, doi:10.3762/bjoc.20.202

• ellipsoids of 50% probability). The hydrogen atoms except those of hydroxy groups are omitted. The X-ray structures of catechols 6 (a) and 8 (b) (the thermal ellipsoids of 50% probability). The hydrogen atoms except those of hydroxy groups are omitted. Fragment of the pack of catechol 5 in crystal (the H

O,S,Se-containing Biginelli products based on cyclic β-ketosulfone and their postfunctionalization

• Kateryna V. Dil and
• Vitalii A. Palchykov

Beilstein J. Org. Chem. 2024, 20, 2143–2151, doi:10.3762/bjoc.20.184

• of condensed thiazoles and tetrazoles. In silico assessment of ADMET parameters shows that most compounds meet the lead-likeness requirements. The biological profiles of new compounds demonstrate high probability levels of activity against the following pathogens/diseases: Candida albicans, Alphis

• biotargets (pathogens, species, diseases) for new synthesized compounds. If we focus on high levels of biological activity probability (80% and above), the following pathogens and diseases may be potential areas of interest: Alphis gossypii, Tripomastigote Chagas, Candida albicans, Tcruzi amastigota

Radical reactivity of antiaromatic Ni(II) norcorroles with azo radical initiators

• Siham Asyiqin Shafie,
• Ryo Nozawa,
• Hideaki Takano and
• Hiroshi Shinokubo

Beilstein J. Org. Chem. 2024, 20, 1967–1972, doi:10.3762/bjoc.20.172

• governed the regioselectivity. Reactivities of norcorroles with various reagents. Top and side views of the X-ray structures of a) 2a and b) 1 [2]. Mesityl groups and hydrogen atoms were omitted for clarity. Thermal ellipsoids are drawn at 50% probability. UV–vis–NIR absorption spectra of 1 and 2a in

Ugi bisamides based on pyrrolyl-β-chlorovinylaldehyde and their unusual transformations

• Alexander V. Tsygankov,
• Vladyslav O. Vereshchak,
• Tetiana O. Savluk,
• Serhiy M. Desenko,
• Valeriia V. Ananieva,
• Oleksandr V. Buravov,
• Yana I. Sakhno,
• Svitlana V. Shishkina and
• Valentyn A. Chebanov

Beilstein J. Org. Chem. 2024, 20, 1773–1784, doi:10.3762/bjoc.20.156

• . Molecular structure of ethyl (Z)-4-(3-(N-(4-bromophenyl)-2-chloroacetamido)-4-(tert-butylamino)-1-chloro-4-oxobut-1-en-1-yl)-3,5-dimethyl-1H-pyrrole-2-carboxylate (8c) according to the X-ray diffraction study. Non-hydrogen atoms are presented as thermal ellipsoids with 50% probability. Molecular structure

• of ethyl (E)-4-(4-(tert-butylamino)-3,4-dioxobut-1-en-1-yl)-3,5-dimethyl-1H-pyrrole-2-carboxylate (10d) according to X-ray diffraction data. Non-hydrogen atoms are presented as thermal ellipsoids with 50% probability. Molecular structure of ethyl 4-(3-(N-(4-bromophenyl)-2-chloroacetamido)-4-(tert

• -butylamino)-4-oxobutanoyl)-3,5-dimethyl-1H-pyrrole-2-carboxylate (12e) according to the X-ray diffraction data. Non-hydrogen atoms are presented as thermal ellipsoids with 50% probability. The use of α,β-unsaturated aldehydes in the Ugi reaction. Comparison of isocyanide conversion conditions. Hydrolysis of

Harnessing unprotected deactivated amines and arylglyoxals in the Ugi reaction for the synthesis of fused complex nitrogen heterocycles

• Javier Gómez-Ayuso,
• Pablo Pertejo,
• Tomás Hermosilla,
• Israel Carreira-Barral,
• Roberto Quesada and
• María García-Valverde

Beilstein J. Org. Chem. 2024, 20, 1758–1766, doi:10.3762/bjoc.20.154

• (right). The thermal ellipsoid plot (Olex2) is at the 40% probability level. X-ray diffraction structure of dipyrrolopiperazinone 12c. The thermal ellipsoid plot (Olex2) is at the 40 % probability level. Synthesis of benzodiazepinones 5 from anthranilic acid derivatives. Diastereoselective one-pot

Oxidation of benzylic alcohols to carbonyls using N-heterocyclic stabilized λ³-iodanes

• Thomas J. Kuczmera,
• Pim Puylaert and
• Boris J. Nachtsheim

Beilstein J. Org. Chem. 2024, 20, 1677–1683, doi:10.3762/bjoc.20.149

• coordination of the triflate to two positions of the iodane. Thermal ellipsoids are displayed with 50% probability. Selected bond lengths and angles: I1–N1: 2.44(4) Å; I1–O1: 1.94(9) Å; I1–O2: 3.04(1) Å; C1–I1–N1: 73.5(8)°; O1–I1–N1: 166.6(5)°; N1–I1–C1–O1: 177.8(3)°. 1H NMR spectra of the time-dependent

Generation of multimillion chemical space based on the parallel Groebke–Blackburn–Bienaymé reaction

• Evgen V. Govor,
• Vasyl Naumchyk,
• Ihor Nestorak,
• Dmytro S. Radchenko,
• Dmytro Dudenko,
• Yurii S. Moroz,
• Olexiy D. Kachkovsky and
• Oleksandr O. Grygorenko

Beilstein J. Org. Chem. 2024, 20, 1604–1613, doi:10.3762/bjoc.20.143

• the relatively high computational costs of this method, we randomly selected 50,000 compounds to represent each database. The dimension reduction algorithm uses molecular features as the starting inputs to generate a few coordinates (in this case, t-SNE1 and t-SNE2) reflecting the probability of the

Synthesis of substituted triazole–pyrazole hybrids using triazenylpyrazole precursors

• Simone Gräßle,
• Laura Holzhauer,
• Nicolai Wippert,
• Olaf Fuhr,
• Martin Nieger,
• Nicole Jung and
• Stefan Bräse

Beilstein J. Org. Chem. 2024, 20, 1396–1404, doi:10.3762/bjoc.20.121

• ORTEP diagrams of triazole products 21sd and 21vg with the thermal ellipsoids shown at 50% probability. NaAsc = sodium ascorbate. One-pot synthesis of triazole–pyrazole hybrid 21gd. aOne-pot setup yielded 21gd with unknown impurities; bwith an additional evaporation step after the triazene cleavage, a

Competing electrophilic substitution and oxidative polymerization of arylamines with selenium dioxide

• Vishnu Selladurai and
• Selvakumar Karuthapandi

Beilstein J. Org. Chem. 2024, 20, 1221–1235, doi:10.3762/bjoc.20.105

• + Na]+ calcd for C54H48N6NaO18, 1091.2917; found, 1091.2885; FTIR (KBr) ν̃max: 3444, 3354, 1677, 1625, 1423, 1304, 1237, 820 cm−1. X-ray data Table 2 and Table 3 show single-crystal X-ray structure refinement data. Molecular structure of 3. Thermal ellipsoids drawn at 50% probability. Selected bond

• lengths (Å): O(1)–C(7) 1.2207 (16), N(1)–C(7) 1.3356 (17), N(1)–C(1) 1.4193 (16), N(1)–H(1) 0.8600. Molecular structure of 9. Thermal ellipsoids drawn at 50% probability. Selected bond lengths (Å): O(1)–C(7) 1.2192 (18), N(1)–C(7) 1.3396, N(1)–C(1) 1.4050 (19), N(1)–H(1) 0.8600, O(2)–C(2) 1.3674 (18), O(2

• )–C(8) 1.420 (2). Molecular structure of 13. Thermal ellipsoids drawn at 50% probability. Selected bond lengths (Å): O(3)–C(7) 1.2070 (16), O(1)–C(7) 1.3322 (16), N(1)–H(1) 0.8600, N(1)–C(6) 1.4044 (16), N(1)–C(9) 1.3440 (16), O(2)–C(9) 1.2160 (16). Molecular structure of 10. Thermal ellipsoids drawn

Two-fold addition reaction of silylene to C₆₀: structural and electronic properties of a bis-adduct

• Masahiro Kako,
• Masato Kai,
• Masanori Yasui,
• Michio Yamada,
• Yutaka Maeda and
• Takeshi Akasaka

Beilstein J. Org. Chem. 2024, 20, 1179–1188, doi:10.3762/bjoc.20.100

• C60 and quaternary carbons of the Dip groups are indicated by grey circles. ORTEP drawing of 3 showing thermal ellipsoids at the 50% probability level at 100 K. Hydrogen atoms are omitted for clarity. (a) Partial structures of isomers of Dip2SiC60. (b) Optimized structures of 2a and 2c. Hydrogen atoms

Mild and efficient synthesis and base-promoted rearrangement of novel isoxazolo[4,5-b]pyridines

• Vladislav V. Nikol’skiy,
• Mikhail E. Minyaev,
• Maxim A. Bastrakov and
• Alexey M. Starosotnikov

Beilstein J. Org. Chem. 2024, 20, 1069–1075, doi:10.3762/bjoc.20.94

• molecule is not shown), 13c (top right), and 13d (bottom) with thermal ellipsoids set at a 50% probability level. Intermolecular hydrogen bonds are drawn with dashed lines. Methods for the synthesis of isoxazolo[4,5-b]pyridines: (A) annulation of an isoxazole fragment to a pyridine ring; (B) annulation of

Synthesis and properties of 6-alkynyl-5-aryluracils

• Ruben Manuel Figueira de Abreu,
• Till Brockmann,
• Alexander Villinger,
• Peter Ehlers and
• Peter Langer

Beilstein J. Org. Chem. 2024, 20, 898–911, doi:10.3762/bjoc.20.80

• molecules within and between a layer with two molecules at the top and the bottom of the unit cell. b) Determined from X-ray structural analysis at 123 K. Element color: carbon (grey), hydrogen (white), oxygen (red) and nitrogen (blue). The thermal ellipsoids are drawn at the 50% probability level. UV–vis

A laterally-fused N-heterocyclic carbene framework from polysubstituted aminoimidazo[5,1-b]oxazol-6-ium salts

• Andrew D. Gillie,
• Matthew G. Wakeling,
• Bethan L. Greene,
• Louise Male and
• Paul W. Davies

Beilstein J. Org. Chem. 2024, 20, 621–627, doi:10.3762/bjoc.20.54

• complexes from 6a. The single crystal X-ray diffraction structures of 13 and 14 have ellipsoids drawn at 50% probability, with hydrogens and solvent omitted for clarity. Selected bond angles and distances: 13: C1–Au: 1.98 Å, Au–Cl: 2.28 Å, N2–Au: 3.65 Å. N1–C1–N3: 102.7°, N3–C1–Au: 129.5°, N1–C1–Au: 127.1

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

• important. A selective hydration of the polar moiety while keeping the pyrene moiety stable can relatively strengthen the stability of conformation 2. Thus, as the polarity of the solvent increases, the probability of conformation 2 appearance is expected to increase. Mechanism of bi-stability in PASE on

• II. Thus, as the polarity of the solvent increases, the probability of the appearance of conformation II is expected to increase. Then, conditions of the temperature and the external pressure of gases have to be chosen properly, too. We need to keep the pyrene part stable in the whole procedures

• increase in the probability that the active center of the antigen/antibody reaction reacts with the antigen. To realize a good temperature condition, the barrier height should be close to or even less than 0.3 eV. Reducing the barrier height may be achieved by optimizing the solution to achieve nearly

Synthesis of photo- and ionochromic N-acylated 2-(aminomethylene)benzo[b]thiophene-3(2Н)-ones with a terminal phenanthroline group

• Vladimir P. Rybalkin,
• Sofiya Yu. Zmeeva,
• Lidiya L. Popova,
• Irina V. Dubonosova,
• Olga Yu. Karlutova,
• Oleg P. Demidov,
• Alexander D. Dubonosov and
• Vladimir A. Bren

Beilstein J. Org. Chem. 2024, 20, 552–560, doi:10.3762/bjoc.20.47

• of compound 2b in acetonitrile before (1) and after 15 s (2), 35 s (3), 75 s (4), 2.5 min (5) and 5 min (6) of irradiation with light of 436 nm (c 5.0 × 10−5 mol·L−1). Molecular structure of O-acylated isomer 3b. Thermal ellipsoids are drawn at the 50% probability level. Fragment of the molecular

Pseudallenes A and B, new sulfur-containing ovalicin sesquiterpenoid derivatives with antimicrobial activity from the deep-sea cold seep sediment-derived fungus Pseudallescheria boydii CS-793

• Zhen Ying,
• Xiao-Ming Li,
• Sui-Qun Yang,
• Hong-Lei Li,
• Xin Li,
• Bin-Gui Wang and
• Ling-Hong Meng

Beilstein J. Org. Chem. 2024, 20, 470–478, doi:10.3762/bjoc.20.42

• . Key 1H-1H COSY (bond lines), and HMBC (red arrows) correlations of 1–3. NOE correlations of compounds 1 and 2 (solid line indicates β-orientation and dashed lines represent α-orientation). X-ray crystal structure of compounds 1–3 (with a thermal ellipsoid probability of 50%). Proposed biosynthetic

Enhanced host–guest interaction between [10]cycloparaphenylene ([10]CPP) and [5]CPP by cationic charges

• Eiichi Kayahara,
• Yoshiyuki Mizuhata and
• Shigeru Yamago

Beilstein J. Org. Chem. 2024, 20, 436–444, doi:10.3762/bjoc.20.38

• sp2 carbon of [10]CPP within 0.30 nm. HOMO−1, HOMO, LUMO, and LUMO+1 orbitals of [10]CPP⊃[5]CPP2+ (1), [5]CPP2+, and [10]CPP. X-ray crystal structure of [10]CPP⊃[5]CPP2+[B(C6F5)4]2. a) Side and b) top views of ORTEP drawings. The thermal ellipsoids are scaled at the 50% probability level. All hydrogen

Facile approach to N,O,S-heteropentacycles via condensation of sterically crowded 3H-phenoxazin-3-one with ortho-substituted anilines

• Eugeny Ivakhnenko,
• Vasily Malay,
• Pavel Knyazev,
• Nikita Merezhko,
• Nadezhda Makarova,
• Oleg Demidov,
• Gennady Borodkin,
• Andrey Starikov and
• Vladimir Minkin

Beilstein J. Org. Chem. 2024, 20, 336–345, doi:10.3762/bjoc.20.34

• , Supporting Information File 1. Thermal ellipsoids are drawn at the 50% probability level. UV–vis spectra of 6,8-di-tert-butyl-2-(arylamino)-3H-phenoxazin-3-ones 4a–h (toluene, c = 2⋅10−5 M, l = 1 cm, T = 293 K). Molecular structure of ethyl 2,4-di-tert-butyl-14H-quinoxalino[2,3-b]phenoxazine-10-carboxylate

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

• ) and side view (b) of the X-ray crystal structure of thiepine 3b showing its bent conformation. Thermal ellipsoids are shown at the 50% probability level, and all hydrogen atoms as well as propyl groups on imide substituents have been omitted for clarity. Reprinted with permission from [57]. Copyright

Comparison of glycosyl donors: a supramer approach

• Anna V. Orlova,
• Nelly N. Malysheva,
• Maria V. Panova,
• Nikita M. Podvalnyy,
• Michael G. Medvedev and
• Leonid O. Kononov

Beilstein J. Org. Chem. 2024, 20, 181–192, doi:10.3762/bjoc.20.18

• measurement of the quartz standards (to monitor the instrument stability). Each measurement at a particular concentration was repeated 10 times, then averaged and plotted against concentration. The standard deviations were calculated by using the Student’s distribution (95% probability) and did not exceed 1

• % unless specified otherwise, see the error bars; the error bar is on the order of the symbol size if not visible). The standard deviations were calculated by using the Student’s distribution (95% probability). The grey boxes in the figure are drawn to guide the eye and designate different ranges of

Optimizing reaction conditions for the light-driven hydrogen evolution in a loop photoreactor

• Pengcheng Li,
• Daniel Kowalczyk,
• Johannes Liessem,
• Mohamed M. Elnagar,
• Dariusz Mitoraj,
• Radim Beranek and
• Dirk Ziegenbalg

Beilstein J. Org. Chem. 2024, 20, 74–91, doi:10.3762/bjoc.20.9

• significance of the chosen parameters was evaluated by analysis of variance (ANOVA). The “Prob>F” probability value gives the estimation of whether the parameter has a significant effect on the response, and generally a parameter with a probability value less than 0.05 is considered as significant. A

• probability value larger than 0.10 renders the parameter generally as insignificant [35]. It is evident from Table 2 that light intensity and inert gas flow can be regarded as significant, while the photocatalyst amount and the stirring speed are insignificant. In addition to this analysis, it is necessary to