Investigation of a bimetallic terbium(III)/copper(II) chemosensor for the detection of aqueous hydrogen sulfide

• Parvathy Mini,
• Michael R. Grace,
• Genevieve H. Dennison and
• Kellie L. Tuck

Beilstein J. Org. Chem. 2024, 20, 2818–2826, doi:10.3762/bjoc.20.237

• hydrogen sulfide. Hydrogen sulfide (H2S) is now recognised as a significant gaseous signaling molecule, alongside nitric oxide and carbon monoxide; it belongs to the biologically active group known as "gaseous mediators" or "gasotransmitters" [1]. In mammalian systems, H2S is predominantly biosynthesized

Mechanochemical difluoromethylations of ketones

• Jinbo Ke,
• Pit van Bonn and
• Carsten Bolm

Beilstein J. Org. Chem. 2024, 20, 2799–2805, doi:10.3762/bjoc.20.235

• by these findings, we now explored difluoromethylation reactions with compounds bearing less nucleophilic functional groups. Ketones caught our particular attention as they contain a weak nucleophilic carbonyl oxygen adjacent to an electrophilic carbonyl carbon. Previous studies have focused on

• sodium fluoride catalyst, with simple ketones, which resulted in the formation of difluoromethyl 2,2-difluorocyclopropyl ethers (Scheme 1B). Although the reactions worked well, it is also noteworthy that the use of TFDA as reagent, liberated fluoro(trimethyl)silane (TMSF), carbon dioxide, and ozone

C–C Coupling in sterically demanding porphyrin environments

• Liam Cribbin,
• Brendan Twamley,
• Nicolae Buga,
• John E. O’ Brien,
• Raphael Bühler,
• Roland A. Fischer and
• Mathias O. Senge

Beilstein J. Org. Chem. 2024, 20, 2784–2798, doi:10.3762/bjoc.20.234

• illustrates that coupling phenyl, thiophene or other aryl moieties at this position would be extremely difficult. Furthermore, the distance between the o-bromine atoms and the nearest carbon neighbor of the β-ethyl groups is 3.7 Å, further complicates the success of coupling at this position. As discussed

Access to optically active tetrafluoroethylenated amines based on [1,3]-proton shift reaction

• Yuta Kabumoto,
• Eiichiro Yoshimoto,
• Bing Xiaohuan,
• Masato Morita,
• Motohiro Yasui,
• Shigeyuki Yamada and
• Tsutomu Konno

Beilstein J. Org. Chem. 2024, 20, 2776–2783, doi:10.3762/bjoc.20.233

• reports on the preparation of chiral molecules possessing a tetrafluoroethylene unit on an asymmetric carbon center in a high optical purity, and to the best of our knowledge, only the following have been published so far (Scheme 1). As a highly enantioselective synthesis, there has been a pioneering work

• a tetrafluoroethylene group on an asymmetric carbon center. In order to overcome the current lack of synthetic methods for preparing such molecules, we came up with the idea of utilizing the [1,3]-proton shift reaction reported by Soloshonok et al. In 1997, Soloshonok et al. reported that

• , the negative charge generated on the imine carbon can be delocalized, hence the transition state is stabilized and the reaction proceeds smoothly. On the other hand, when the substituent R is an alkyl group, the negative charge generated on the imine carbon is an unstable factor, and therefore the

Copper-catalyzed yne-allylic substitutions: concept and recent developments

• Shuang Yang and
• Xinqiang Fang

Beilstein J. Org. Chem. 2024, 20, 2739–2775, doi:10.3762/bjoc.20.232

• rise to a series of differently substituted 1,4-enynes with monofluoroalkyl units in high yields and ee values (Scheme 18, 18a–i). The reaction effectively overcomes the drawbacks of low activity of tertiary carbon nucleophiles and instability of fluorinated compounds. Preliminary mechanistic studies

• stereoselective aromatization serves as a pivotal step in the transfer of central chirality to axial chirality (Scheme 52). To harness the full potential of CO2 as a renewable and abundant carbon source, He et al. [82] proposed an innovative strategy that married asymmetric yne-allylic substitution with CO2

Computational design for enantioselective CO₂ capture: asymmetric frustrated Lewis pairs in epoxide transformations

• Maxime Ferrer,
• Iñigo Iribarren,
• Tim Renningholtz,
• Ibon Alkorta and
• Cristina Trujillo

Beilstein J. Org. Chem. 2024, 20, 2668–2681, doi:10.3762/bjoc.20.224

• , The University of Manchester, Oxford Road, Manchester, M13 9PL, UK Trinity Biomedical Sciences Institute, School of Chemistry, The University of Dublin, Trinity College, D02 R590 Dublin 2, Ireland 10.3762/bjoc.20.224 Abstract Carbon capture and utilisation (CCU) technologies offer a compelling

• strategy to mitigate rising atmospheric carbon dioxide levels. Despite extensive research on the CO2 insertion into epoxides to form cyclic carbonates, the stereochemical implications of this reaction have been largely overlooked, despite the prevalence of racemic epoxide solutions. This study introduces

• catalyst efficiency and selectivity in sustainable chemistry applications. Keywords: asymmetric catalysis; carbon dioxide; CO2; epoxide; frustrated Lewis pairs (FLPs); volcano plot; Introduction The field of frustrated Lewis pairs (FLPs) has flourished since their seminal discovery in 2006 by Stephan and

The scent gland composition of the Mangshan pit viper, Protobothrops mangshanensis

• Jonas Holste,
• Paul Weldon,
• Donald Boyer and
• Stefan Schulz

Beilstein J. Org. Chem. 2024, 20, 2644–2654, doi:10.3762/bjoc.20.222

• vibrations. The linear gas chromatographic retention index (I) of Dm was 1595, lower than, e.g., 1621 reported for methyl 2,11-dimethyldodecanoate [18], indicating a multi-branched carbon chain. The number and positions of methyl groups along the chain can be estimated using the empirical calculation system

Applications of microscopy and small angle scattering techniques for the characterisation of supramolecular gels

• Connor R. M. MacDonald and
• Emily R. Draper

Beilstein J. Org. Chem. 2024, 20, 2608–2634, doi:10.3762/bjoc.20.220

• number of structural features, but the sample preparation required can lead to significant changes in the materials morphology. EM requires many preparative steps to allow structures to be imaged including the application of an ultrathin coating of carbon, gold, or platinum. These are applied to conduct

Efficient modification of peroxydisulfate oxidation reactions of nitrogen-containing heterocycles 6-methyluracil and pyridine

• Alfiya R. Gimadieva,
• Yuliya Z. Khazimullina,
• Aigiza A. Gilimkhanova and
• Akhat G. Mustafin

Beilstein J. Org. Chem. 2024, 20, 2599–2607, doi:10.3762/bjoc.20.219

• temperature, concentrated H2SO4 was slowly added until pH 6–7 according to litmus paper and left standing overnight (12 h). The precipitated crystals were filtered off, washed with water, acetone, and dried in air. The crude product was recrystallized from water with activated carbon. The yield of compound 2

Transition-metal-free synthesis of arylboronates via thermal generation of aryl radicals from triarylbismuthines in air

• Yuki Yamamoto,
• Yuki Konakazawa,
• Kohsuke Fujiwara and
• Akiya Ogawa

Beilstein J. Org. Chem. 2024, 20, 2577–2584, doi:10.3762/bjoc.20.216

• variety of transition-metal-catalyzed reactions and photoredox reactions using arylboronates as aryl sources have been energetically investigated for the construction of carbon–carbon or carbon–heteroatom bonds [12][13][14][15]. The preparation of arylboronates often requires pre-functionalized substrates

• diborons can capture the in situ-generated carbon-centered radicals [28][29][30][31][32][33][34][35][36]. Among the aryl sources in organic synthesis, triarylbismuthines are shelf-stable and easy-to-handle reagents with appropriate reactivities in transition-metal-catalyzed reactions and radical reactions

Anion-dependent ion-pairing assemblies of triazatriangulenium cation that interferes with stacking structures

• Yohei Haketa,
• Takuma Matsuda and
• Hiromitsu Maeda

Beilstein J. Org. Chem. 2024, 20, 2567–2576, doi:10.3762/bjoc.20.215

• PF6− anions located above the TATA+ plane (Figure 3b,c and Figure 5b,c). Three of the fluorine atoms of BF4− and PF6− were pointed toward the TATA+ plane. The offset angles for Cl−, BF4−, and PF6− to the TATA+ central carbon were 87.7°, 78.1°, and 84.3°, respectively. The distances between fluorine

• 2+-B(C6F5)4−, the distance between the boron of B(C6F5)4− and the central carbon of TATA+ was 7.32 Å, with an offset angle of 47.1° (Figure 3d, Figure 7a, and Figures S14 and S20 in Supporting Information File 1). On the other hand, in 2+-PCCp−, the PCCp− unit (centroid of the five-membered ring

• ) was located 5.55 Å from the central carbon of TATA+ with an offset angle of 69.4° (Figure 3e, Figure 7b, and Figures S15 and S21 in Supporting Information File 1). The PCCp− unit was inclined at 29.9° to the TATA+ plane, with the closest distance of 3.31 Å between the cyano-N and TATA+ mean plane. Two

A review of recent advances in electrochemical and photoelectrochemical late-stage functionalization classified by anodic oxidation, cathodic reduction, and paired electrolysis

• Nian Li,
• Ruzal Sitdikov,
• Ajit Prabhakar Kale,
• Joost Steverlynck,
• Bo Li and
• Magnus Rueping

Beilstein J. Org. Chem. 2024, 20, 2500–2566, doi:10.3762/bjoc.20.214

• . However, it should be noted that anodic oxidations often require electrodes with high resistance to oxidation, such as platinum electrodes, or inert electrodes with a highly developed surface, like reticulated vitreous carbon (RVC). Anodic oxidations generally involve the evolution of hydrogen (indicated

• anode to form a sulfoxide. Subsequent hydrogen atom abstraction by a chlorine radical leads to the formation of an intermediate carbon radical, whose resonant intermediate reacts with another chlorine radical to produce the desired α-chlorosulfoxide product (Scheme 14). 1.1.2 Unsaturated bond

• method for the formation of C–S bonds [25]. This method achieves the difunctionalization of a carbon atom by reacting isocyanide 2-isocyanoacetate with a thiophenol and an alcohol. The scope is very broad for thiophenols, alcohols, and isocyanides, and even alkyl thiols are compatible. In addition to

Visible-light-mediated flow protocol for Achmatowicz rearrangement

• Joachyutharayalu Oja,
• Sanjeev Kumar and
• Srihari Pabbaraja

Beilstein J. Org. Chem. 2024, 20, 2493–2499, doi:10.3762/bjoc.20.213

• -flow platform to provide the corresponding dihydropyranone products (3a–p) with moderate to good yields (51–85%), Figure 1. We investigated several furanol derivatives by altering the substituents at two critical positions: the hydroxymethyl carbon and the 5-position of the furan ring, that were

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

• illustrating the data mining and preprocessing steps for chemical reaction datasets. This process includes data collection, filtering, completion, and atom mapping. In the depicted example, formaldehyde, which contributes a carbon atom to the product, is classified as a reactant due to its active involvement

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

• -substitued resorcinols are notoriously difficult to engage in the cyclization reaction towards resorcin[n]arenes since the nucleophilic character of the attacking aromatic carbon is diminished. Specifically, there is no literature information on 2-chlororesorcinol or 2-iodoresorcinol being used in this

Photoredox-catalyzed intramolecular nucleophilic amidation of alkenes with β-lactams

• Valentina Giraldi,
• Giandomenico Magagnano,
• Daria Giacomini,
• Pier Giorgio Cozzi and
• Andrea Gualandi

Beilstein J. Org. Chem. 2024, 20, 2461–2468, doi:10.3762/bjoc.20.210

• -amidyl radicals uses activated N–O amide derivatives capable of generating amidyl radicals through fragmentation [18][19]. The direct formation of amidyl radicals in the presence of a carbon alkyl chain could lead to a competitive 1,5-hydrogen atom transfer (1,5-HAT) [20][21][22], limiting the direct

Hypervalent iodine-mediated cyclization of bishomoallylamides to prolinols

• Smaher E. Butt,
• Konrad Kepski,
• Jean-Marc Sotiropoulos and
• Wesley J. Moran

Beilstein J. Org. Chem. 2024, 20, 2455–2460, doi:10.3762/bjoc.20.209

• Pierre Angot, 64053 Pau Cedex 09, France School of Pharmacy and Bioengineering, Keele University, Keele, Staffordshire ST5 5JX, United Kingdom 10.3762/bjoc.20.209 Abstract A change in mechanism was observed in the hypervalent iodine-mediated cyclization of N-alkenylamides when the carbon chain between

• 15 [23]. As would be expected, one regioisomer and a 1:1 mixture of diastereomers was formed. Conclusion We have demonstrated that a change in mechanism occurs in the cyclization of N-alkenylamides when increasing the chain length between the amide and the alkene. When there are one or two carbon

• atoms separating the functional groups, cyclization at the amide oxygen occurs to generate five- and six-membered rings, respectively. However, when there is a three-carbon atom link, the corresponding seven-membered ring is not formed. Instead, cyclization at nitrogen occurs to generate a five-membered

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

Facile preparation of fluorine-containing 2,3-epoxypropanoates and their epoxy ring-opening reactions with various nucleophiles

• Yutaro Miyashita,
• Sae Someya,
• Tomoko Kawasaki-Takasuka,
• Tomohiro Agou and
• Takashi Yamazaki

Beilstein J. Org. Chem. 2024, 20, 2421–2433, doi:10.3762/bjoc.20.206

• executed at −78 °C under the action of LDA [29]. Moreover, by using the epoxyester 2b as the representative substrate, clarification of its reactivity was carried out by mixing with 1) heteronucleophiles like amines, thiols, and magnesium halides, 2) softer carbon nucleophiles such as malonates, and 3

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

Efficient one-step synthesis of diarylacetic acids by electrochemical direct carboxylation of diarylmethanol compounds in DMSO

• Hisanori Senboku and
• Mizuki Hayama

Beilstein J. Org. Chem. 2024, 20, 2392–2400, doi:10.3762/bjoc.20.203

• Pt cathode and a Mg anode in the presence of carbon dioxide induced reductive C(sp3)−O bond cleavage at the benzylic position in diarylmethanol compounds and subsequent fixation of carbon dioxide to produce diarylacetic acids in good yield. This protocol provides a novel and simple approach to

• diarylacetic acids from diarylmethanol species and carbon dioxide without transformation of the hydroxy group into appropriate leaving groups, such as halides and esters including carbonates. Keywords: C(sp3)–O bond cleavage; diarylacetic acid; diarylmethanol; electrochemical reduction; fixation of carbon

• presence of carbon dioxide to give the corresponding phenylacetic acids [12]. We found that alkyl benzyl carbonates and benzal diacetates (benzylidene diacetates) were also applicable to electrochemical carboxylation with C(sp3)–O bond cleavage at the benzylic position, yielding phenylacetic acids [13] and

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

• average lengths of the С–С bonds of six-membered carbon cycle С(1–6) (1.396 ± 0.013 Å in 5, 1.397 ± 0.009 Å in 6, 1.396 ± 0.012 Å in 8) are typical for catechols [50][55][56]. The presence of complex polyfunctional substituents affects their spatial location regarding a catechol fragment. In most cases

Asymmetric organocatalytic synthesis of chiral homoallylic amines

• Nikolay S. Kondratyev and
• Andrei V. Malkov

Beilstein J. Org. Chem. 2024, 20, 2349–2377, doi:10.3762/bjoc.20.201

• excellent enantioselectivities (89–98% ee) and low to moderate yields (48–72%). The homologation step proceeds via the stereoretentive 1,2-migration of the vinyl group from the tetracoordinated boron to the highly electrophilic carbon of the diazomethane, concerted with the elimination of the nitrogen

• trifluoromethylated amine 146 was obtained in 75% yield and 83% ee. The scope of this reaction is yet to be explored. In 2022, Momiyama and co-workers presented a novel synthetic approach towards enantioenriched homoallylic amines 150 that bear a chiral centre on the β-carbon, based on an asymmetric [1,3

Hydrogen-bond activation enables aziridination of unactivated olefins with simple iminoiodinanes

• Phong Thai,
• Lauv Patel,
• Diyasha Manna and
• David C. Powers

Beilstein J. Org. Chem. 2024, 20, 2305–2312, doi:10.3762/bjoc.20.197

• center [26][27]. Despite the prevalence of acid-activation in promoting carbon [28], oxygen [29][30], sulfur [31], chlorine [32], and fluorine [33] transfer reactions of hypervalent iodine compounds, these strategies have not been applied to activation of iminoiodinanes for nitrene transfer chemistry. We

gem-Difluorination of carbon–carbon triple bonds using Brønsted acid/Bu₄NBF₄ or electrogenerated acid

• Mizuki Yamaguchi,
• Hiroki Shimao,
• Kengo Hamasaki,
• Keiji Nishiwaki,
• Shigenori Kashimura and
• Kouichi Matsumoto

Beilstein J. Org. Chem. 2024, 20, 2261–2269, doi:10.3762/bjoc.20.194

• University, 3-4-1 Kowakae, Higashi-osaka, Osaka, 577-8502, Japan 10.3762/bjoc.20.194 Abstract gem-Difluorination of carbon–carbon triple bonds was conducted using Brønsted acids, such as Tf2NH and TfOH, combined with Bu4NBF4 as the fluorine source. The electrochemical oxidation of a Bu4NBF4/CH2Cl2 solution

• containing alkyne substrates could also give the corresponding gem-difluorinated compounds (in-cell method). The ex-cell electrolysis method was also applicable for gem-difluorination of alkynes. Keywords: carbon–carbon triple bonds; chemical method; electrochemistry; gem-difluorination; Introduction

• blocks for further transformations. We have focused on the investigation of gem-difluorination of carbon–carbon triple bonds, because this procedure is one of the most simple but powerful and straightforward methods. In addition, there have been a few reports in the literature that seem to mainly rely on