Selectfluor and alcohol-mediated synthesis of bicyclic oxyfluorination compounds by Wagner–Meerwein rearrangement

• Ziya Dağalan,
• Muhammed Hanifi Çelikoğlu,
• Saffet Çelik,
• Ramazan Koçak and
• Bilal Nişancı

Beilstein J. Org. Chem. 2024, 20, 1462–1467, doi:10.3762/bjoc.20.129

• used as nucleophiles. First, optimization experiments were carried out for fluoroalkoxy reactions with benzonorbornadiene (1a, Table 1). As a result of experiments conducted in six different solvents at room temperature with 1.0 equivalent of selectflor and 1.0 equivalent of methanol, it was observed

Synthesis of 4-functionalized pyrazoles via oxidative thio- or selenocyanation mediated by PhICl₂ and NH₄SCN/KSeCN

• Jialiang Wu,
• Haofeng Shi,
• Xuemin Li,
• Jiaxin He,
• Chen Zhang,
• Fengxia Sun and
• Yunfei Du

Beilstein J. Org. Chem. 2024, 20, 1453–1461, doi:10.3762/bjoc.20.128

• 3a and their derivatization. Plausible reaction mechanism. Optimization of oxidative thiocyanation of pyrazole.a Supporting Information Supporting Information File 28: Synthetic details and compound characterization data. Funding We acknowledge the National Key Research and Development Program of

Challenge N- versus O-six-membered annulation: FeCl₃-catalyzed synthesis of heterocyclic N,O-aminals

• Giacomo Mari,
• Lucia De Crescentini,
• Gianfranco Favi,
• Fabio Mantellini,
• Diego Olivieri and
• Stefania Santeusanio

Beilstein J. Org. Chem. 2024, 20, 1412–1420, doi:10.3762/bjoc.20.123

• of a high water amount results in catalyst deactivation. Based on these results and what was observed in the optimization tests (Table 1, entry 6), we extended the reaction time but used ACN as solvent, which possesses a higher water content with respect to DCM (experiment C, Scheme 5). Gratifyingly

• formation of N,O-aminals 5 and hemiaminals 6. Control mechanistic experiments. Optimization conditions for the Lewis acid-catalyzed intramolecular cyclization of 4a. Supporting Information Supporting Information File 16: General experimental information, synthetic procedures, analytical data and NMR

Hypervalent iodine-catalyzed amide and alkene coupling enabled by lithium salt activation

• Akanksha Chhikara,
• Fan Wu,
• Navdeep Kaur,
• Prabagar Baskaran,
• Alex M. Nguyen,
• Zhichang Yin,
• Anthony H. Pham and
• Wei Li

Beilstein J. Org. Chem. 2024, 20, 1405–1411, doi:10.3762/bjoc.20.122

• cycle for the hypervalent iodine-catalyzed amide and alkene coupling. Hypervalent iodine-catalyzed olefin difunctionalizations background. Amide and alkene reaction optimization studies. Supporting Information Supporting Information File 14: Spectral characterization of the products and kinetic studies

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

• 50 °C. This optimization allowed for the isolation of the corresponding azides 19a–v in yields of 51% to quantitative (Scheme 2), usually with durations of 3–16 h. Longer reaction times were necessary for some CN-substituted triazene derivatives (19o, 19q, 19s, 19v), especially in combination with

Synthetic applications of the Cannizzaro reaction

• Bhaskar Chatterjee,
• Dhananjoy Mondal and
• Smritilekha Bera

Beilstein J. Org. Chem. 2024, 20, 1376–1395, doi:10.3762/bjoc.20.120

• . where they applied a FeCl3-based chiral catalyst with an N,N′-dioxide ligand [74]. The optimization of the reaction conditions revealed the L–RaPr2–FeCl3 complex being superior and delivering good to excellent results, thus witnessing a broad substrate scope taking different glyoxal monohydrates 1 and

Synthesis of 1,2,3-triazoles containing an allomaltol moiety from substituted pyrano[2,3-d]isoxazolones via base-promoted Boulton–Katritzky rearrangement

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

Beilstein J. Org. Chem. 2024, 20, 1334–1340, doi:10.3762/bjoc.20.117

• hydrate a. Synthesis of products 6. Reaction conditions: 1 (0.5 mmol), hydrazine hydrate (1.5 mmol, 0.08 g), EtOH (5 ml). Proposed reaction mechanism for the formation of products 6. Synthesis of methylated product 7. Optimization of the reaction conditionsa. Supporting Information Supporting Information

Transition-metal-catalyst-free electroreductive alkene hydroarylation with aryl halides under visible-light irradiation

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

Beilstein J. Org. Chem. 2024, 20, 1327–1333, doi:10.3762/bjoc.20.116

• this transformation, iodobenzene was successfully converted to the corresponding product 3ka under slightly modified reaction conditions (see Table S1 in Supporting Information File 1 for optimization details). Under the modified conditions, aryl iodides with various electron-donating groups including

Sustainable tandem acylation/Diels–Alder reaction toward versatile tricyclic epoxyisoindole-7-carboxylic acids in renewable green solvents

• Ayhan Yıldırım

Beilstein J. Org. Chem. 2024, 20, 1308–1319, doi:10.3762/bjoc.20.114

• maleamic acid precursors. Optimization of IMDAF cycloaddition using different solvents.a Synthesized tricyclic epoxyisoindole-7-carboxylic acidsa. Supporting Information Supporting Information File 88: Tables S1 and S2, Cartesian coordinates of the optimized structures and copies of NMR spectra.

Diameter-selective extraction of single-walled carbon nanotubes by interlocking with Cu-tethered square nanobrackets

• Guoqing Cheng and
• Naoki Komatsu

Beilstein J. Org. Chem. 2024, 20, 1298–1307, doi:10.3762/bjoc.20.113

• complexation, a significant red-shift of the dipyrrin band to 465 nm was observed due to the metal coordination with the dipyrrin moieties in 4b. To compare the structures of 1a and 1b, they are calculated through geometry optimization with the density functional theory (DFT) method. The alkyl chains at the

• and their complexes with interlocking structures, respectively, after the geometry optimization with the GFN2-xTB method. The 45 different kinds of SWNTs with length of ≥3.0 nm and diameter range of 0.7–1.2 nm are chosen for the calculation (Table S1, Supporting Information File 1). The relationship

• (Figure 5b). Computational methods The geometry optimization and frequency analysis of Cu-nanobrackets 1a and 1b were performed at (U)ωB97X-D/6-31+G(d,p)-SDD(Cu) [30][31][32][33] level using the Gaussian 16 program [34], with calculating the pre-resonance Raman activities at 488 nm excitation wavelength

Phenotellurazine redox catalysts: elements of design for radical cross-dehydrogenative coupling reactions

• Alina Paffen,
• Christopher Cremer and
• Frederic W. Patureau

Beilstein J. Org. Chem. 2024, 20, 1292–1297, doi:10.3762/bjoc.20.112

• 2,8-dimethoxy substitution (PTeZ15) allowed to significantly increase catalytic activity (3aa, 68% after 3 h), still at 1 mol % loading. Encouraged by this trend, which seemed to indicate that the more π-electron-donating substituents increase catalytic activity, we continued structural optimization

• . Our future research efforts in the area of Te(II) catalysis will likely focus on milder coupling reactions on the one hand, and/or on novel more robust and more active ligand designs on the other. In particular, more investigations will likely be needed regarding the optimization of the possible Te

Synthesis of indano[60]fullerene thioketone and its application in organic solar cells

• Yong-Chang Zhai,
• Shimon Oiwa,
• Shinobu Aoyagi,
• Shohei Ohno,
• Tsubasa Mikie,
• Jun-Zhuo Wang,
• Hirofumi Amada,
• Koki Yamanaka,
• Kazuhira Miwa,
• Naoyuki Imai,
• Takeshi Igarashi,
• Itaru Osaka and
• Yutaka Matsuo

Beilstein J. Org. Chem. 2024, 20, 1270–1277, doi:10.3762/bjoc.20.109

• differences between t-Bu-FIDO and t-Bu-FIDS, the density functional theory (DFT) method was employed using the B3LYP hybrid functional. The 6-31G* basis set was used for the geometry optimization and frequency calculation. The thiocarbonyl group in FIDS was found to have an out of plane bending vibration

• , w/w)/PEDOT:PSS/Ag. (b) ITO/ZnO/fullerene:PNTz4T (2:1, w/w)/MoOx/Ag. ITO, indium tin oxide; PEDOT:PSS = poly(3,4-ethylenedioxythiophene) polystyrene sulfonate. Optimization of reaction conditions for the treatment of t-Bu-FIDO with Lawesson's reagent.a Reaction of R-FIDO with Lawesson's reagent.a

Domino reactions of chromones with activated carbonyl compounds

• Peter Langer

Beilstein J. Org. Chem. 2024, 20, 1256–1269, doi:10.3762/bjoc.20.108

• chromone. During the optimization of the conditions, the best yields were in many cases obtained when chloride was employed as the leaving group. However, for some other products the yields were slightly better in case of employment of 3-bromochromone. Most of the yields were higher than 70%, in several

Synthesis and optical properties of bis- and tris-alkynyl-2-trifluoromethylquinolines

• Stefan Jopp,
• Franziska Spruner von Mertz,
• Peter Ehlers,
• Alexander Villinger and
• Peter Langer

Beilstein J. Org. Chem. 2024, 20, 1246–1255, doi:10.3762/bjoc.20.107

• ; isolated yields. Optimization of the Sonogashira reaction.a Spectroscopic data of 6a, 9a, 12a, 12c, and 12e in dichloromethane (10−5 M) at 20 °C (λex = 380 nm). Supporting Information Supporting Information File 74: Experimental part.

Stability trends in carbocation intermediates stemming from germacrene A and hedycaryol

• Naziha Tarannam,
• Prashant Kumar Gupta,
• Shani Zev and
• Dan Thomas Major

Beilstein J. Org. Chem. 2024, 20, 1189–1197, doi:10.3762/bjoc.20.101

• calculations were performed using Gaussian 16 (revision A.03) [37] and Q-Chem (version 5.4.2) [38], with default tight geometry optimization convergence criteria (10−5 au) and SCF convergence thresholds (10−8 au). All stationary points were characterized by frequency calculations. Throughout this article, only

• interactions and blue represents repulsive interactions. Additionally, we carried out natural bonding orbital (NBO) analysis using the NBO 3.1 program [42] as implemented in the Gaussian 16 package. The computations are performed at the same level of theory that we chose initially for optimization (M06-2X/6-31

• noteworthy that optimization with ωB97M-V/6-31+G(d,p) and single point calculations performed with M06-2X and ωB97M-V using the triple-ζ def2-TZVPP basis set provide similar trends for both germacrene and hedycaryol carbocations (the energy comparison plots for the different methods are added in Supporting

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

• 5,6-sila-fulleroid (2d) structures (Figure 6). The optimized structure of 2a was found to be more stable than that of 2c by 19.23 kcal/mol. In contrast, optimization using initial structures of 2b and 2d afforded the structures of 2a and 2c, respectively. Based on these results, the optimized

Bismuth(III) triflate: an economical and environmentally friendly catalyst for the Nazarov reaction

• Manoel T. Rodrigues Jr.,
• Aline S. B. de Oliveira,
• Ralph C. Gomes,
• Amanda Soares Hirata,
• Lucas A. Zeoly,
• Hugo Santos,
• João Arantes,
• Catarina Sofia Mateus Reis-Silva,
• João Agostinho Machado-Neto,
• Leticia Veras Costa-Lotufo and
• Fernando Coelho

Beilstein J. Org. Chem. 2024, 20, 1167–1178, doi:10.3762/bjoc.20.99

• the Nazarov reaction, using models already studied in the literature [33][34][35][36][37][38][39][40][41][42][43]. We investigated several conditions, such as the type of catalyst, temperature, solvent, and amount of catalyst (Table 1). Our optimization studies began with the reaction of substrate 9aa

• , and the dotted line indicates 75% reduction in cell viability. Compounds that reduced cell viability by at least 75% at 5 µg/mL are highlighted in the graph. Previous methods describing decarboxylation reactions of indanones and xanthenones. Optimization of the reaction conditions. Evaluation of the

Novel route to enhance the thermo-optical performance of bicyclic diene photoswitches for solar thermal batteries

• Akanksha Ashok Sangolkar,
• Rama Krishna Kadiyam and
• Ravinder Pawar

Beilstein J. Org. Chem. 2024, 20, 1053–1068, doi:10.3762/bjoc.20.93

• results will certainly have a remarkable impact for applications in solar energy harvesting and storage. Computational Details The molecular structures of all studied dienes and photoproducts were fully relaxed without any geometrical or symmetrical constraints. The geometry optimization was performed

Structure–property relationships in dicyanopyrazinoquinoxalines and their hydrogen-bonding-capable dihydropyrazinoquinoxalinedione derivatives

• Tural N. Akhmedov,
• Ajeet Kumar,
• Daken J. Starkenburg,
• Kyle J. Chesney,
• Khalil A. Abboud,
• Novruz G. Akhmedov,
• Jiangeng Xue and
• Ronald K. Castellano

Beilstein J. Org. Chem. 2024, 20, 1037–1052, doi:10.3762/bjoc.20.92

• deep (<−6.0 eV). FMO energies are of great importance not only for the stability but also for device optimization. Raising the HOMO energy level can facilitate hole injection when using Pt electrodes [33], consequently enabling the fabrication of ambipolar devices supporting both hole and electron

A Diels–Alder probe for discovery of natural products containing furan moieties

• Alyssa S. Eggly,
• Namuunzul Otgontseren,
• Carson B. Roberts,
• Amir Y. Alwali,
• Haylie E. Hennigan and
• Elizabeth I. Parkinson

Beilstein J. Org. Chem. 2024, 20, 1001–1010, doi:10.3762/bjoc.20.88

• the probe was synthesized in good yields, the optimization of the Diels–Alder reaction was undertaken. The Diels–Alder reaction (Figure 3A) was optimized utilizing 3-furoic acid (14) as it fits the requirement of having an electron-withdrawing group in the three position and was an inexpensive

Innovative synthesis of drug-like molecules using tetrazole as core building blocks

• Jingyao Li,
• Ajay L. Chandgude,
• Qiang Zheng and
• Alexander Dömling

Beilstein J. Org. Chem. 2024, 20, 950–958, doi:10.3762/bjoc.20.85

• . Trimethylsilyl azide is considered as a safe replacement of metal azides. We started the solvent optimization with MeOH and H2O as solvent system at room temperature, however, it did not yield any product even after 3 days (Table 1, entry 1). The use of DMF to improve the solubility of the paraformaldehyde solid

• was also unsuccessful to increase the product yield. The increased use of microwave conditions in organic synthesis [20] and our previous promising studies on microwave-assisted MCRs [21], motivated us to use microwave conditions for further optimization. Accordingly, we investigated several sets of

• ). This method is applicable to different amines, isocyanide and acid components including Ugi-4-component and Ugi-tetrazole reactions proving the desired products with low to moderate yields. The Ugi reactions were performed in MeOH at room temperature for 24 hours and without any further optimization

Enantioselective synthesis of β-aryl-γ-lactam derivatives via Heck–Matsuda desymmetrization of N-protected 2,5-dihydro-1H-pyrroles

• Arnaldo G. de Oliveira Jr.,
• Martí F. Wang,
• Rafaela C. Carmona,
• Danilo M. Lustosa,
• Sergei A. Gorbatov and
• Carlos R. D. Correia

Beilstein J. Org. Chem. 2024, 20, 940–949, doi:10.3762/bjoc.20.84

• inhibitor (R)-rolipram (5b) [15], and the commercial drug (R)-baclofen hydrochloride (6), used to treat muscle spasticity from spinal cord injury and multiple sclerosis [16]. Results and Discussion Desymmetrization of N-protected 2,5-dihydro-1H-pyrroles Some initial results and reaction optimization Based

• before. Before exploring the reactivity of the olefin towards other aryldiazonium salts, we performed a brief optimization of the process by testing several other N,N-ligands. Therefore, five other N,N-ligands were evaluated as follows: PyraBox (L2), QuinOx (L3), PyOx L4 and L5, and PyriBOx (L6) (Figure

• –Matsuda reaction of the protected 2,5-dihydro-1H-pyrroles with aryldiazonium salts catalyzed by a (S)-PyraBox–palladium complex. Optimization of the reaction conditions with tosyl-protected pyrroline 1b.a Supporting Information Supporting Information File 4: Experimental procedures and characterization

One-pot Ugi-azide and Heck reactions for the synthesis of heterocyclic systems containing tetrazole and 1,2,3,4-tetrahydroisoquinoline

• Jiawei Niu,
• Yuhui Wang,
• Shenghu Yan,
• Yue Zhang,
• Xiaoming Ma,
• Qiang Zhang and
• Wei Zhang

Beilstein J. Org. Chem. 2024, 20, 912–920, doi:10.3762/bjoc.20.81

• effort was then focused on the optimization of the intramolecular Heck reaction of 5a for making 1,2,3,4-tetrahydroisoquinoline 6a. A systematic evaluation of different catalysts and ligands, solvents, bases, as well as reaction temperatures and times was conducted (Table 1). The Heck reaction of 5a was

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

• carried out by application of the Suzuki–Miyaura cross-coupling. The optimization was carried out with 3a as the model compound (Table 1). The starting material 3a is a sterically hindered system in which the bromine is only partially accessible, due to the large residue. This could be the reason for the

• . Synthesis of 1,3-dimethyl-5-aryl-6-[2-(aryl)ethynyl]uracils 5a–t. Reaction conditions: 3 (1 equiv), boronic acid (1.2 equiv), Pd(PPh3)4 (5 mol %), NaOH (3 equiv), dioxane/water 5:1, 100 °C, 1 h. aYields of isolated products. Optimization of the reaction conditions for the synthesis of 5a. Photophysical data

Three-component N-alkenylation of azoles with alkynes and iodine(III) electrophile: synthesis of multisubstituted N-vinylazoles

• Jun Kikuchi,
• Roi Nakajima and
• Naohiko Yoshikai

Beilstein J. Org. Chem. 2024, 20, 891–897, doi:10.3762/bjoc.20.79

• iodo(III)azolation using various azoles (a single example of iodo(III)azolation using pyrazole was reported in [28]). Table 1 summarizes the results of the optimization of the reaction conditions for the vinylation of pyrazole (2a) with 1-phenyl-1-propyne (3a) and BXT (1). Upon examination of various

• . Optimization of reaction conditions.a Supporting Information Supporting Information File 22: Experimental procedures and characterization data of new compounds. Acknowledgements We thank the Central Glass Co., Ltd. for the generous donation of 1,1,1,3,3,3-hexafluoro-2-phenylpropan-2-ol (HFAB). Funding This