(E,Z)-1,1,1,4,4,4-Hexafluorobut-2-enes: hydrofluoroolefins halogenation/dehydrohalogenation cascade to reach new fluorinated allene

• Nataliia V. Kirij,
• Andrey A. Filatov,
• Yurii L. Yagupolskii,
• Sheng Peng and
• Lee Sprague

Beilstein J. Org. Chem. 2024, 20, 452–459, doi:10.3762/bjoc.20.40

• 2 with one equivalent of DBU (Table 1, entry 4) led to the same results as for the Hünig’s base (Table 1, entry 1). The use of two equivalents of DBU (Table 1, entry 6) led to the complete conversion of the initial substrate, but the selectivity of the reaction was significantly reduced in this case

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

• -complementary interaction between [5]CPP2+ and [10]CPP. The same size selectivity was observed for the complex formation between neutral CPPs [31]. As the protons in the 1H NMR of [10]CPP2+ and neutral [5]CPP resonate at 4.72 and 7.84 ppm, respectively [21], the observed chemical shifts of the complex indicate

Mono or double Pd-catalyzed C–H bond functionalization for the annulative π-extension of 1,8-dibromonaphthalene: a one pot access to fluoranthene derivatives

• Nahed Ketata,
• Linhao Liu,
• Ridha Ben Salem and
• Henri Doucet

Beilstein J. Org. Chem. 2024, 20, 427–435, doi:10.3762/bjoc.20.37

• , carbon 2 should be more reactive than carbon 4 in the Pd-catalyzed direct arylation, but we previously observed that the main product of the reaction was C4-arylated 1,3-dichlorobenzene [32]. This selectivity could be due to the steric hindrance of the chloro substituents. As a result, in the presence of

Green and sustainable approaches for the Friedel–Crafts reaction between aldehydes and indoles

• Periklis X. Kolagkis,
• Eirini M. Galathri and
• Christoforos G. Kokotos

Beilstein J. Org. Chem. 2024, 20, 379–426, doi:10.3762/bjoc.20.36

• reactivities in this methodology, affording low product yields, which limits some applications. The selectivity of this protocol was also investigated (Scheme 4). It was surprisingly observed that aromatic aldehydes produced the corresponding BIM as the major product in the presence of other substrates

Mechanisms for radical reactions initiating from N-hydroxyphthalimide esters

• Carlos R. Azpilcueta-Nicolas and
• Jean-Philip Lumb

Beilstein J. Org. Chem. 2024, 20, 346–378, doi:10.3762/bjoc.20.35

• undergo addition to the heterocyclic radical acceptor 19 through a ternary transition state 20 involving hydrogen bonding interactions with the chiral phosphate co-catalyst. Notably, a follow-up report revealed that the radical addition is reversible, and that the selectivity determining step involves the

Unveiling the regioselectivity of rhodium(I)-catalyzed [2 + 2 + 2] cycloaddition reactions for open-cage C₇₀ production

• Cristina Castanyer,
• Anna Pla-Quintana,
• Anna Roglans,
• Albert Artigas and
• Miquel Solà

Beilstein J. Org. Chem. 2024, 20, 272–279, doi:10.3762/bjoc.20.28

• cyclohexadiene-fused adducts, denoted as α-INT 4 and β-INT 4, which will ultimately evolve into the final bis(fulleroid) reaction products [33]. As the site-selectivity of the reaction depends on these two consecutive steps, it indicates a preference for the α-bonds over the β-bonds, consistent with the

Additive-controlled chemoselective inter-/intramolecular hydroamination via electrochemical PCET process

• Kazuhiro Okamoto,
• Naoki Shida and
• Mahito Atobe

Beilstein J. Org. Chem. 2024, 20, 264–271, doi:10.3762/bjoc.20.27

• radical acceptor moieties. Therefore, we investigated the origin of this selectivity under electrochemical conditions. Results and Discussion Anodic oxidation of uridine derivative 1 was performed in a CH2Cl2/Bu4NPF6 (0.1 M) electrolyte system using a carbon felt (CF) anode and a Pt cathode in the

• 1. Detailed CV analysis indicated that the size of the hydrogen bond complex determined the selectivity, and HFIP played a crucial role in expanding the hydrogen bond network. These results provide fundamental insights beneficial for the design of PCET-based redox reaction systems under

Catalytic multi-step domino and one-pot reactions

• Svetlana B. Tsogoeva

Beilstein J. Org. Chem. 2024, 20, 254–256, doi:10.3762/bjoc.20.25

• simple compounds. In particular, catalytic domino reactions and one-pot processes with excellent selectivity and functional-group tolerance are of significant interest to industrial and academic research. In the so-called domino reactions, all of the required reagents, the catalyst, and a solvent are

Substitution reactions in the acenaphthene analog of quino[7,8-h]quinoline and an unusual synthesis of the corresponding acenaphthylenes by tele-elimination

• Ekaterina V. Kolupaeva,
• Narek A. Dzhangiryan,
• Alexander F. Pozharskii,
• Oleg P. Demidov and
• Valery A. Ozeryanskii

Beilstein J. Org. Chem. 2024, 20, 243–253, doi:10.3762/bjoc.20.24

• for compounds containing a quinoline fragment in various fields of research. At the same time, quinoline bases are a popular platform for the molecular design of polycyclic systems with receptor properties; they easily form proton complexes with high stability and selectivity [5][6]. This, in turn

Chiral phosphoric acid-catalyzed transfer hydrogenation of 3,3-difluoro-3H-indoles

• Yumei Wang,
• Guangzhu Wang,
• Yanping Zhu and
• Kaiwu Dong

Beilstein J. Org. Chem. 2024, 20, 205–211, doi:10.3762/bjoc.20.20

• achieving high selectivity. Also, an obvious solvent effect on the enantioselectivity was observed (Table 1, entries 7–10). Very low ee values of product 2a were detected when the reaction was performed in DMSO or MeOH (Table 1, entries 7 and 8), while using DCE or toluene as the solvent the

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

• (trifluoroacetyl vs chloroacetyl), at different concentrations (0.05 and 0.15 mol·L−1) led to mutually excluding conclusions concerning their relative reactivity and selectivity, which prevented us from revealing a possible influence of remote protective groups at O-9 on glycosylation outcome. According to the

• critical [57][62] concentrations that separate the concentration ranges, where supramers of similar structures hence chemical properties exist, from other concentration ranges, where supramers that are organized differently and have modified chemical properties (reactivity, selectivity) are present [35

• reasons for the observed increase in the reactivity and selectivity for sialyl donor 2 with a chloroacetyl group at O-9 at high concentration (0.15 mol·L−1) are missing. All this suggests that in the particular case of sialyl donors 1 and 2 studied it is not possible to conclude unambiguously which one of

Synthesis of the 3’-O-sulfated TF antigen with a TEG-N₃ linker for glycodendrimersomes preparation to study lectin binding

• Mark Reihill,
• Hanyue Ma,
• Dennis Bengtsson and
• Stefan Oscarson

Beilstein J. Org. Chem. 2024, 20, 173–180, doi:10.3762/bjoc.20.17

• synthesis starting from unprotected N-acetylgalactosamine and a Lewis acid-promoted reaction starting from per-acetylated galactosamine were initially tested. As reported [11], the Fischer synthesis gives low yields and α-selectivity. The Lewis acid-promoted reaction, which had worked well to produce β

• -linked TEG-spacer glycosides with per-acetylated lactose and 2-phthalimidoglucosamine [1][2] worked well with 2-chloroethanol as a spacer (68%, pure α) but failed with the TEG-Cl spacer [12], why we instead decided to use a thioglycoside donor to introduce the spacer. To ensure α-selectivity a di-tert

Copper-promoted C5-selective bromination of 8-aminoquinoline amides with alkyl bromides

• Changdong Shao,
• Chen Ma,
• Li Li,
• Jingyi Liu,
• Yanan Shen,
• Chen Chen,
• Qionglin Yang,
• Tianyi Xu,
• Zhengsong Hu,
• Yuhe Kan and
• Tingting Zhang

Beilstein J. Org. Chem. 2024, 20, 155–161, doi:10.3762/bjoc.20.14

• , employing activated and unactivated alkyl bromides as the halogenation reagents without additional external oxidants. This method features outstanding site selectivity, broad substrate scope, and excellent yields. Keywords: aminoquinolines; C–H bromination; copper catalysis; regioselectivity; Introduction

1-Butyl-3-methylimidazolium tetrafluoroborate as suitable solvent for BF₃: the case of alkyne hydration. Chemistry vs electrochemistry

• Marta David,
• Elisa Galli,
• Richard C. D. Brown,
• Marta Feroci,
• Fabrizio Vetica and
• Martina Bortolami

Beilstein J. Org. Chem. 2023, 19, 1966–1981, doi:10.3762/bjoc.19.147

• present, the reaction was performed in presence of 1 equiv of BF3·Et2O and a reaction time of 1 h (Table 4, entry 4). In this way, the selectivity was improved and only the hydration product 2d was obtained in 81% yield. For electron-rich terminal alkynes, the corresponding ketones could not be

• 1f decreased the selectivity with respect to formation of the hydration product 2f, favouring the condensation product 3f (Table 4, entry 6). On the other hand, an ortho methyl group in 1g favoured formation of the ketone 2g, with a good yield, probably due to the steric hindrance of the aldol

• hydration product 2i with good yield, reducing its reactivity (Table 4, entry 9). With 1,4-diethynylbenzene (1j) both the products of mono (2j) and bis hydration (2jj) were obtained under all conditions tested (see Table S1, Supporting Information File 1). The highest selectivity for the generation of 2j

Beyond n-dopants for organic semiconductors: use of bibenzo[d]imidazoles in UV-promoted dehalogenation reactions of organic halides

• Kan Tang,
• Megan R. Brown,
• Chad Risko,
• Melissa K. Gish,
• Garry Rumbles,
• Phuc H. Pham,
• Oana R. Luca,
• Stephen Barlow and
• Seth R. Marder

Beilstein J. Org. Chem. 2023, 19, 1912–1922, doi:10.3762/bjoc.19.142

• achieved using highly reducing metals, molecular reductants can potentially enable more selectivity, as required for the use of such reactions in the synthesis of molecules bearing various functional groups. In particular, Wanzlick dimers (C=C-bonded dimers of N-heterocyclic carbenes, Figure 1a, i) have

• process (given the reduction potentials in Table 2). As shown in Scheme 1, we found 2-iodobenzyl chloride is cleanly converted to benzyl chloride under the standard conditions used in Table 2 (see Supporting Information File 1, Table S4 for more details). This selectivity is not typically achievable using

Anion–π catalysis on carbon allotropes

• M. Ángeles Gutiérrez López,
• Mei-Ling Tan,
• Giacomo Renno,
• Augustina Jozeliūnaitė,
• J. Jonathan Nué-Martinez,
• Javier Lopez-Andarias,
• Naomi Sakai and
• Stefan Matile

Beilstein J. Org. Chem. 2023, 19, 1881–1894, doi:10.3762/bjoc.19.140

• planar π surfaces of anion–π catalysts. The A/D product ratio is thus a convenient measure for anion–π catalysis, the larger the better, with A/D > 1, the intrinsic selectivity for decarboxylation has been inverted [2][3][18]. Applying lessons from simpler anion–π catalysts, trialkylamines were tethered

• derivatives. In fullerene 8, this is an amide with a short ethylene tether for the tertiary amine (Figure 3). Fullerene 8 catalyzed the formation of the addition product 6 with high selectivity over the decarboxylation product 7 [12]. The experimental product ratio A/D8 was divided by the product ratio A/D9

• product 26 and exo product 27 [64][65][66]. With the less powerful fullerene catalyst 14, the increase of the exo/endo selectivity compared to the fullerene-free control 12, i.e., exo/endo14/12 = 1.1, was negligible [12]. With the best fullerene catalyst 21, the presence of the fullerene made the

Controlling the reactivity of La@C₈₂ by reduction: reaction of the La@C₈₂ anion with alkyl halide with high regioselectivity

• Yutaka Maeda,
• Saeka Akita,
• Mitsuaki Suzuki,
• Michio Yamada,
• Takeshi Akasaka,
• Kaoru Kobayashi and
• Shigeru Nagase

Beilstein J. Org. Chem. 2023, 19, 1858–1866, doi:10.3762/bjoc.19.138

• reduction of La@C2v-C82 is an easy and effective method for controlling its reactivity and selectivity via ionization for the production of La@C2v-C82 derivatives. Experimental General: All chemicals and solvents were obtained from Wako, TCI, and Aldrich and were used without further purification unless

A novel recyclable organocatalyst for the gram-scale enantioselective synthesis of (S)-baclofen

• Gyula Dargó,
• Dóra Erdélyi,
• Balázs Molnár,
• Péter Kisszékelyi,
• Zsófia Garádi and
• József Kupai

Beilstein J. Org. Chem. 2023, 19, 1811–1824, doi:10.3762/bjoc.19.133

• , acetonitrile, with 91–100% efficiency, and the catalyst was reused in five reaction cycles without the loss of activity and selectivity. Keywords: baclofen; catalyst recovery; lipophilic cinchona squaramide; organocatalysis; stereoselective catalysis; Introduction In today’s chemical industry, catalytic

• flow systems. Accordingly, the main recycling methods rely on the immobilization of catalysts on heterogeneous supports, however, this could often lead to the deterioration of activity and/or selectivity [27]. A possible solution to avoid these drawbacks is the heterogenization of the catalyst after a

• addition of trans-β-nitrostyrene (12) and acetylacetone (13). Choosing the best solvent for the reaction is crucial, thus, solubility tests were carried out (Table 1). Since homogeneous catalysts usually exhibit higher activity and selectivity than their heterogeneous counterparts [27], our aim was to

Recent advancements in iodide/phosphine-mediated photoredox radical reactions

• Tinglan Liu,
• Yu Zhou,
• Junhong Tang and
• Chengming Wang

Beilstein J. Org. Chem. 2023, 19, 1785–1803, doi:10.3762/bjoc.19.131

• specificity in the synthesis of β-alkylated styrenes 5. This study underscored the broad applicability and selectivity of the NaI/PPh3 catalytic system in facilitating the synthesis of β-alkylated styrenes using diverse redox-active esters. It is worth highlighting that triphenylphosphine is not essential for

• of fused ketones 34, eliminating the need for transition-metal catalysts or oxidants. The technique offered a broad substrate scope, remarkable selectivity, and simple reaction conditions. A plausible mechanism had been proposed for the photocatalytic decarboxylative [3 + 2]/[4 + 2] annulation, as

Selectivity control towards CO versus H₂ for photo-driven CO₂ reduction with a novel Co(II) catalyst

• Lisa-Lou Gracia,
• Philip Henkel,
• Olaf Fuhr and
• Claudia Bizzarri

Beilstein J. Org. Chem. 2023, 19, 1766–1775, doi:10.3762/bjoc.19.129

• concentration of this greenhouse gas by upcycling. Selectivity towards CO2-reduction products is highly desirable, although it can be challenging to achieve since the metal-hydrides formation is sometimes favored and leads to H2 evolution. In this work, we designed a cobalt-based catalyst, and we present herein

• its physicochemical properties. Moreover, we tailored a fully earth-abundant photocatalytic system to achieve specifically CO2 reduction, optimizing efficiency and selectivity. By changing the conditions, we enhanced the turnover number (TON) of CO production from only 0.5 to more than 60 and the

• selectivity from 6% to 97% after four hours of irradiation at 420 nm. Further efficiency enhancement was achieved by adding 1,1,1,3,3,3-hexafluoropropan-2-ol, producing CO with a TON up to 230, although at the expense of selectivity (54%). Keywords: carbon monoxide selectivity; cobalt(II) complex; copper(I

Unprecedented synthesis of a 14-membered hexaazamacrocycle

• Anastasia A. Fesenko and
• Anatoly D. Shutalev

Beilstein J. Org. Chem. 2023, 19, 1728–1740, doi:10.3762/bjoc.19.126

• aprotic solvents (1,4-dioxane or DME), the selectivity of the reaction dramatically decreased and a mixture of 5 and 6 along with significant amounts of various unidentified byproducts was formed. For example, the reaction of 4 with N2H4∙H2O (4.1 equiv) in refluxing 1,4-dioxane for 2 h, followed by

Quinoxaline derivatives as attractive electron-transporting materials

• Zeeshan Abid,
• Liaqat Ali,
• Sughra Gulzar,
• Faiza Wahad,
• Raja Shahid Ashraf and
• Christian B. Nielsen

Beilstein J. Org. Chem. 2023, 19, 1694–1712, doi:10.3762/bjoc.19.124

• enhanced sensitivity, selectivity, and accuracy in biomarker detection, physiological parameter monitoring, and disease diagnosis. Furthermore, their efficient charge transport properties make them valuable in improving energy storage and conversion systems, including batteries and supercapacitors. The

Tying a knot between crown ethers and porphyrins

• Maksym Matviyishyn and
• Bartosz Szyszko

Beilstein J. Org. Chem. 2023, 19, 1630–1650, doi:10.3762/bjoc.19.120

• binding towards different cationic species [48][87][113]. Additional efforts have been directed towards designing and synthesising alkali and other cation sensors based on capped crown ether porphyrins, providing enhanced sensitivity and selectivity for specific cations [114][115][116][117][118][119

Radical chemistry in polymer science: an overview and recent advances

• Zixiao Wang,
• Feichen Cui,
• Yang Sui and
• Jiajun Yan

Beilstein J. Org. Chem. 2023, 19, 1580–1603, doi:10.3762/bjoc.19.116

• a powerful tool for polymer crosslinking and preparation of materials with enhanced properties. 3.3 Polymer surface modification When modifying the surface of polymers, chemical selectivity typically plays a minor role, while harsh reaction conditions are useful for the modification of chemically

C–H bond functionalization: recent discoveries and future directions

• Indranil Chatterjee

Beilstein J. Org. Chem. 2023, 19, 1568–1569, doi:10.3762/bjoc.19.114

• well as famous Noble-prize-winning cross-couplings, therefore approaching another step up towards sustainability. Likewise, a free-radical process is also a classical way to functionalize nonactivated C−H bonds in which site selectivity arises either from the relative strength of the C−H bonds or from