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Search for "reactions" in Full Text gives 3072 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.
Chitosan-supported CuI-catalyzed cascade reaction of 2-halobenzoic acids and amidines for the synthesis of quinazolinones
Beilstein J. Org. Chem. 2025, 21, 839–844, doi:10.3762/bjoc.21.67
- in organic transformations [22][23][24], we intended to investigate the use of chitosan-supported copper as a catalyst for the synthesis of quinazolinones from 2-halobenzoic acids and amidines under mild reaction conditions (Scheme 1c). Results and Discussion The initial reactions commenced with 2
- obtained (Table 1, entry 19). With the optimized conditions in hand, we explored the substrate scope of the CS@CuI-catalyzed cascade reactions of 2-halobenzoic acids (including 2-iodobenzoic acid and 2-bromobenzoic acid) with amidines (Scheme 2). Initially, when the amidine substituent (R2) is a methyl
- group, we investigated the reactions with various substituted 2-halobenzoic acids. The reactivity of 2-iodobenzoic acid derivatives (3a–d, 90−96% yields) was higher than that of 2-bromobenzoic acid derivatives (3a–d, 57−73% yields), the electronic properties of the substituents on the benzene ring had
Synthesis and photoinduced switching properties of C7-heteroatom containing push–pull norbornadiene derivatives
Beilstein J. Org. Chem. 2025, 21, 807–816, doi:10.3762/bjoc.21.64
- synthesized (Scheme 1, bottom). In contrast to the previously synthesized large library carbon-based NBDs [40], only a few heterocyclic derivatives were successfully isolated. During the monitoring of additional reactions attempting to reproduce the literature scope, in most cases traces of new NBD species
Regioselective formal hydrocyanation of allenes: synthesis of β,γ-unsaturated nitriles with α-all-carbon quaternary centers
Beilstein J. Org. Chem. 2025, 21, 800–806, doi:10.3762/bjoc.21.63
- -system configuration promotes selective functionalization, enabling the synthesis of various complex products through a single transformation [17][18][19]. Therefore, allenes have become versatile intermediates in numerous transition-metal-catalyzed reactions [20][21]. Despite extensive studies on the
- scope for the formal hydrocyanation with 1,1-disubstituted and 1,1,3-trisubstituted allenes was examined (Scheme 3). All reactions were performed in the presence of 5 mol % IPrCuCl to generate the allylaluminum reagents in situ, followed by cyanation at room temperature for 30 min. This method
- converted to the desired nitrile 5g in high yield. Gram-scale reactions were conducted using allenes to demonstrate the practical applicability of this hydrocyanation method (Scheme 5). Allene 1q (1.04 g, 7.2 mmol) and allene 4b (1.08 g, 6.0 mmol) were effectively transformed into nitrile products 3q and 5b
Recent advances in the electrochemical synthesis of organophosphorus compounds
Beilstein J. Org. Chem. 2025, 21, 770–797, doi:10.3762/bjoc.21.61
- efficiency of reactions [14][15][16][17][18][19][20][21]. Organophosphorous compounds are essential materials with broad applications in medicinal chemistry, synthesis, agriculture, as ligands, and intermediates to prepare complex compounds. Due to their importance, scientists have introduced many studies in
- generates an electric current. Some of its applications include batteries (e.g., lithium-ion batteries) and fuel cells. These cells are usually in a divided state. Electrolytic cell These cells require an external voltage to drive chemical reactions. They use electrical energy to carry out a non-spontaneous
- reduction occur in separate compartments, separated by a diaphragm or salt bridge, to prevent reactant mixing and improve efficiency (e.g., Daniel cell). However, in undivided cells, both reactions occur in a single compartment without separation, resulting in a more straightforward design but potentially
New advances in asymmetric organocatalysis II
Beilstein J. Org. Chem. 2025, 21, 766–769, doi:10.3762/bjoc.21.60
- cycloaddition reactions [1][2][3][4]. The history of scientific discoveries, however, is rarely defined by single specific dates that can unambiguously be connected to the discoveries. Instead, the chronology often seems to be quite convoluted but also ultimately more interesting, as can also be seen for
- -catalyzed reactions and biocatalysis. In the past 25 years, organocatalysis has grown rapidly into a broad area of research, with industrial applications now being developed [16]. The usefulness of any idea or methodology is ultimately often measured by its applications. The robustness, reliability, as well
- organocatalytic cycloaddition reactions of unsaturated imines. A broad variety of activation modes, as well as catalyst structures, was covered and found to be useful in affording a diverse array of chiral N-heterocycles [27]. In my group, we recently became interested in atroposelective catalytic syntheses
Development and mechanistic studies of calcium–BINOL phosphate-catalyzed hydrocyanation of hydrazones
Beilstein J. Org. Chem. 2025, 21, 755–765, doi:10.3762/bjoc.21.59
- through calcium catalysis [8][9][10]. Asymmetric synthesis has also been achieved via, e.g., 1,4-addition and [3 + 2] cycloaddition of 3-tetrasubstituted oxindoles with a calcium Pybox catalyst [11][12], or through enantioselective Friedel–Crafts and carbonyl–ene reactions [13]. Since the pioneering
- in elucidating the mechanism by which these bifunctional compounds act as powerful catalysts [21][22][23][24][25][26][27][28][29]. Since Ishihara disclosed the crucial role of calcium in many purportedly purely organocatalytic BINOL phosphate-catalyzed reactions [30][31], several asymmetric synthesis
- that might similarly occur also in related addition reactions of alkenes, for example. After 11E had reacted with TMSCN, adduct 13 forms, 3.8 kcal·mol−1 more stable than the competing unreactive adduct obtained from "Z" conformation. Outside from the catalytic cycle, 12 could be further hydrolyzed in a
Orthogonal photoswitching of heterobivalent azobenzene glycoclusters: the effect of glycoligand orientation in bacterial adhesion
Beilstein J. Org. Chem. 2025, 21, 736–748, doi:10.3762/bjoc.21.57
- 3αMan 5, first order reactions were assumed with the rate constants k5, k7, and k6 (Figure 2C). In order to determine the half-lifes τ1/2 and activation energies Ea of the photoswitching units comprised in the homobivalent glycocluster 6αMan3αMan 2, the decay of the metastable ZZ isomer to the
Synthesis of HBC fluorophores with an electrophilic handle for covalent attachment to Pepper RNA
Beilstein J. Org. Chem. 2025, 21, 727–735, doi:10.3762/bjoc.21.56
- 14 (Figure 2). Synthesis of a bifunctional Pepper dye Encouraged by the efficient attachment of the bromo- and mesyloxypropyl-modified HBC fluorophores to the Pepper aptamer, we generated a bifunctional HBC ligand with a second handle that is available for bioorthogonal reactions. The original
Origami with small molecules: exploiting the C–F bond as a conformational tool
Beilstein J. Org. Chem. 2025, 21, 680–716, doi:10.3762/bjoc.21.54
- angle widening in gem-difluoroalkanes is seen in the rates of the ring-closing methathesis reactions of the dienes 8 and 9 (Figure 3) [25]. The fluorinated substrate 9 cyclises much more efficiently than the non-fluorinated substrate 8, and this was attributed to a thermodynamic effect, i.e., a more
- -membered ring of pyranoses. However, it must be remembered that pyranoses are reactive molecules that can undergo, e.g., glycosylation, and it emerges that fluorine can play a much more significant conformational role during the dynamics of such chemical reactions [125][126][127][128][129][130
- ]. Glycosylation reactions (e.g., 63 → 65 and 64 → 66, Figure 9) proceed via an oxocarbenium intermediate. If fluorine is located at C-2, an electrostatic attraction might be expected between the partially negative fluorine and the positively charged C=O+ moiety, and this interaction would favour one of the half
Photochemically assisted synthesis of phenacenes fluorinated at the terminal benzene rings and their electronic spectra
Beilstein J. Org. Chem. 2025, 21, 670–679, doi:10.3762/bjoc.21.53
- compounds, F8PIC and F8FUL, were obtained through the Wittig-reaction and Mallory-photoreaction sequence (Scheme 2). Thus, reactions between phosphonium salt 5 and specific aldehydes, 10 and 13, followed by photolysis in the presence of I2 and O2, respectively, afforded F8PIC (57%) and F8FUL (52%). F87PHEN
Asymmetric synthesis of fluorinated derivatives of aromatic and γ-branched amino acids via a chiral Ni(II) complex
Beilstein J. Org. Chem. 2025, 21, 659–669, doi:10.3762/bjoc.21.52
- fluorinated amino acids that can be synthesized from a single starting material is a unique feature of this method, making it an important cornerstone of fluoropeptide chemistry. Experimental General information Air- and hydrolysis-sensitive reactions were carried out under exclusion of air and water in
- Schlenk vessels at a Schlenk unit/oil pump vacuum under nitrogen atmosphere. The stated reaction temperatures are the respective values of the silicone oil heating bath. All reactions were stirred with an electric magnetic stirrer. 1H, 13C, and 19F NMR spectra were measured at room temperature with a JEOL
Recent advances in allylation of chiral secondary alkylcopper species
Beilstein J. Org. Chem. 2025, 21, 639–658, doi:10.3762/bjoc.21.51
- attention due to their unique properties in stereoselective allylic substitution. This review highlights recent advances in copper-catalyzed asymmetric allylic substitution reactions with chiral secondary alkylcopper species, encompassing several key strategies for their generation: stereospecific
- substitution reactions began to develop with the groundbreaking work of Takeuchi and Kashio, and subsequent research has revealed that iridium catalysts behave quite differently from their palladium counterparts [18]. The most notable distinction lies in their contrasting regioselectivity patterns. Palladium
- -catalyzed allylic substitution reactions [20]. To address these limitations, copper-catalyzed processes have emerged as a promising alternative. Copper-catalyzed allylic substitutions are distinguished by their unique inner-sphere mechanistic pathway, which enables the incorporation of hard, non-stabilized
Entry to 2-aminoprolines via electrochemical decarboxylative amidation of N‑acetylamino malonic acid monoesters
Beilstein J. Org. Chem. 2025, 21, 630–638, doi:10.3762/bjoc.21.50
- [7][8] (Figure 2, reactions 1 and 2, respectively). Results and Discussion N-Acetylamino malonic acid monoester 9a possessing a tosyl-protected tethered amine was selected as a model substrate for the development of the intramolecular amidation under Hofer–Moest conditions. The acid 9a was prepared
- was not extracted from background-corrected voltammograms. All CV graphs are plotted using IUPAC polarographic convention. Selected examples of α,α-disubstituted cyclic amino acids in drug design. Electrochemical decarboxylative amination reactions. A) Cyclic voltammograms of 6a and 9a at 3 mM and 6
Photocatalyzed elaboration of antibody-based bioconjugates
Beilstein J. Org. Chem. 2025, 21, 616–629, doi:10.3762/bjoc.21.49
- stability, and/or a shorter ADC half-life [14]. Optimization of the drug/antibody ratio (DAR) and payload distribution/location thus becomes significant for ideal ADC design. Given the complexity of biological macromolecules, there are inherent limitations in terms of the types of reactions that can be used
- to modify them. Reactions must be carried out at or near ambient temperatures and near-neutral pH. Aqueous media is often required to solubilize the substrates and/or to prevent denaturation, and reactions are normally carried out under very dilute (micromolar) conditions. As importantly, the highly
- covalent bioconjugation. Effective bioconjugation has been dramatically facilitated by the development of robust bioorthogonal reactions, which has revolutionized the field of chemical biology [17]. A bioorthogonal reactive group can be introduced into proteins via direct chemical coupling on specific
Semisynthetic derivatives of massarilactone D with cytotoxic and nematicidal activities
Beilstein J. Org. Chem. 2025, 21, 607–615, doi:10.3762/bjoc.21.48
- derivatives 2–8. Reagents and reactions conditions: a) (CH3CH2)3N/DMAP and methacryloyl chloride in CH2Cl2; b) (CH3CH2)3N/DMAP and cinnamoyl chloride in CH2Cl2; c) (CH3CH2)3N/DMAP and 4-bromobenzoyl chloride in CH2Cl2; d) (CH3CH2)3N/DMAP and trans-2-methyl-2-butenoyl chloride in CH2Cl2; e) (CH3CH2)3N/DMAP and
Total synthesis of (±)-simonsol C using dearomatization as key reaction under acidic conditions
Beilstein J. Org. Chem. 2025, 21, 601–606, doi:10.3762/bjoc.21.47
- ] and has been used in syntheses of natural products containing aryl quaternary carbon centers [9][10]. Unlike the intramolecular alkylation strategy of a phenol derivative, which can only be applied in basic dearomatization reactions, our approach using an α-iodophenol ether as precursor of the
- two allyl groups into the product, thus avoiding the challenges associated with allyl formation reactions. The chosen synthetic route towards (±)-simonsol C is shown in Scheme 3. Starting with magnolol (11), one of the phenol groups was selectively protected by controlling the equivalents of MOMCl and
- were optimized to achieve product 20 with 85% yield, minimizing potential side reactions. The subsequent dearomatization step is crucial for the construction of the cyclohexadienone unit. Oxidation of compound 20 with PIDA in trifluoroethanol, the original phenol was converted into a quinone moiety
Sequential two-step, one-pot microwave-assisted Urech synthesis of 5-monosubstituted hydantoins from L-amino acids in water
Beilstein J. Org. Chem. 2025, 21, 596–600, doi:10.3762/bjoc.21.46
- methylated amino acids and carbamates (65–75%) [9] or cyanobenziodoxolone (CBX) (54–88%) [10]. Reactions using 1,2-diaza-1,3-dienes, amines, and isocyanates (47–76%) [11], as well as α-amino amides with triphosgene or carbonyldiimidazole (CDI) (41–80%) [12], have also been explored. Other strategies include
- copper(I)-catalyzed reactions (48–71%) [13] and the four-component Ugi reaction [14] yields 48–71% and 27–67%, respectively. In addition, pyroglutamates with isocyanates, which provide exceptionally high yields (97–99%) [15], and dipeptides have been utilized in triflate-activated Mumm’s rearrangement
- substrate reactivity, minor side reactions, or minor losses during microwave irradiation. The remaining part may be caused by factors such as slight volatilization or incomplete conversion under specific use conditions. We found the synthetic procedure facile as the less polar hydantoin products (H2a–c, H2e
Formaldehyde surrogates in multicomponent reactions
Beilstein J. Org. Chem. 2025, 21, 564–595, doi:10.3762/bjoc.21.45
- /bjoc.21.45 Abstract Formaldehyde emerges as a cornerstone in multicomponent reactions, mainly prized for its robust reactivity. Yet, alongside these beneficial traits, this highly reactive C1-building block raises concerns, primarily regarding its toxicity. One notable issue is the challenge of
- controlling the formation of undesired byproducts during its reactions. This review explores alternative C1-building blocks that serve as surrogates for formaldehyde, aiming to mitigate some of the challenges associated with its use in multicomponent reactions. By identifying these alternatives, toxicity
- concerns and improved reaction control can be addressed, paving the way for more efficient and sustainable synthetic methodologies. Keywords: cascade reactions; formaldehyde surrogates; green chemistry; heterocycles; multicomponent reactions; Introduction Organic chemistry is a mature discipline that has
Study of the interaction of 2H-furo[3,2-b]pyran-2-ones with nitrogen-containing nucleophiles
Beilstein J. Org. Chem. 2025, 21, 556–563, doi:10.3762/bjoc.21.44
- structure of used N-nucleophile various types of a heterocyclic system can be obtained. A large number of examples of reactions with substituted amines have been reported in the literature. Generally, this process includes opening of the furanone ring followed by cyclization to the pyrrolone moiety [6][7][8
- pyrrolones such interaction can lead to pyridazinone systems [10][11]. Despite on the plenty of reactions with nitrogen-containing nucleophiles there is only one example of recyclization using furanone with a carbonyl group at position 3 (Scheme 1a, previous work) [6]. However, no work on this type of
Asymmetric synthesis of β-amino cyanoesters with contiguous tetrasubstituted carbon centers by halogen-bonding catalysis with chiral halonium salt
Beilstein J. Org. Chem. 2025, 21, 547–555, doi:10.3762/bjoc.21.43
- of its unique interaction in organic synthesis. Chiral halonium salts have been found to have strong halogen-bonding-donor abilities and work as powerful asymmetric catalysts. Recently, we have developed binaphthyl-based chiral halonium salts and applied them in several enantioselective reactions
- developed chiral halonium salts and applied them to asymmetric reactions such as vinylogous Mannich reactions of cyanomethylcoumarins 6 with isatin-derived ketimines 7 [33][35] and 1,2-addition reaction of thiols to ketimine [34], which formed the corresponding products 8 in high yields with high to
- tetrasubstituted carbon stereogenic centers [42][43][44][45][46]. In 2011, Shibasaki, Matsunaga and co-workers reported strontium or magnesium-catalyzed stereodivergent asymmetric Mannich reactions of an α-isothiocyanato ester with ketimines, which provided the products in excellent yields and
Vinylogous functionalization of 4-alkylidene-5-aminopyrazoles with methyl trifluoropyruvates
Beilstein J. Org. Chem. 2025, 21, 533–540, doi:10.3762/bjoc.21.41
- properties along a C=C double bond [1]. This effect has been established to be very advantageous to expand the range of reactions of different functional groups that can be coupled efficiently through a conjugated π-system. In this context, the addition reaction of vinylogous nucleophiles to carbonyl
- compounds is a significant and important reaction for the selective synthesis of homoallylic alcohols in an efficient and sustainable way [2][3]. As carbonyl compounds, alkyl trifluoropyruvates [4][5] are an interesting class of compounds that have been used in addition reactions of different nucleophiles
- diastereoselectivity at 50 °C (Table 1, entry 16). Finally, the addition of molecular sieves was evaluated (Table 1, entries 17 and 18) affording in both cases lower yields for the reaction product. We also attempted asymmetric reactions using chiral organocatalysts to achieve an enantioselective outcome; however, we
Deep-blue emitting 9,10-bis(perfluorobenzyl)anthracene
Beilstein J. Org. Chem. 2025, 21, 515–525, doi:10.3762/bjoc.21.39
- -step reactions with anthraquinone starting materials [24], or by Ullman coupling reactions of acene bromides with perfluoroalkyl iodides [25]. Notably, direct UV photoinduced reactions between anthracene and perfluoroalkyl iodides in the presence of a reducing agent, Na2S2O3, yielded perfluoroalkylated
- dimeric molecules, instead of expected 9,10-(perfluoroalkyl)2ANTH [26]. To the best of our knowledge, perfluorobenzylation of anthracene has not been reported prior to this study. The only PAH perfluorobenzylations were reported by our group: with CORA using gas-phase solvent-free reactions in sealed
- ampules and with PERY using solution-phase reactions at elevated temperatures in the presence of Cu metal or another reducing agent [22]. In this study we first explored the approaches from our previous work: a high-temperature gas-phase reaction between ANTH and BnFI [18][19], and a solution-phase
Unprecedented visible light-initiated topochemical [2 + 2] cycloaddition in a functionalized bimane dye
Beilstein J. Org. Chem. 2025, 21, 500–509, doi:10.3762/bjoc.21.37
- promising strategy for synthesizing substituted cyclobutanes without the need for ultraviolet irradiation. Keywords: bimane; [2 + 2] cycloaddition; fluorescence; topochemical polymerization; X-ray crystallography; Introduction Topochemical polymerizations refer to polymerization reactions occurring in the
- solid state, which are highly dependent on molecular packing. The concept of topochemical reactions was first introduced by Kohlschütter in 1919 [1], and topochemical polymerizations were systematically studied by Schmidt and co-workers in the 1960s and 1970s [2][3][4]. Schmidt's pioneering work
- primarily focused on [2 + 2] photocycloaddition in the solid state, making it one of the earliest known examples of topochemical polymerization and a valuable method for synthesizing substituted cyclobutanes [5]. These solid-state reactions are highly influenced by the arrangement of monomers within the
Synthesis of N-acetyl diazocine derivatives via cross-coupling reaction
Beilstein J. Org. Chem. 2025, 21, 490–499, doi:10.3762/bjoc.21.36
- switching efficiency in aqueous solutions. In order to investigate the chemistry of this promising photoswitch and to unlock further applications, we now investigate strategies for the synthesis of derivatives, which are based on cross-coupling reactions. Fourteen vinyl-, aryl-, cyano-, and amino
- -substituted diazocines were prepared via Stille, Suzuki, and Buchwald–Hartwig reactions. X-ray structures are presented for derivatives 1, 2 and 7. Keywords: cross-coupling; diazocine; N-acetyl diazocine; photoisomerization; photoswitch; thermal relaxation; Introduction Diazocines are frequently used
- biochemical reactions usually take place in aqueous environments [13]. The substitution of one CH2 group in the CH2CH2 bridge by N–C(=O)–CH3 leads to an intrinsic water solubility of the N-acetyl diazocine 1 (Figure 1) [3]. Furthermore the photoconversion of 1 shows no significant drop in pure water in
Photomechanochemistry: harnessing mechanical forces to enhance photochemical reactions
Beilstein J. Org. Chem. 2025, 21, 458–472, doi:10.3762/bjoc.21.33
- transfer [13][14][15]. Regardless of the mechanistic details of the activation manifold, all photochemical reactions obey two laws: the Grotthuss–Draper and the Einstein–Stark laws [16]. The Grotthuss–Draper law dictates that only absorbed light can induce photochemical transformations within a system. In
- turn demands large volumes of solvents, negatively impacting the sustainability of light-mediated synthesis as it transitions from academic curiosity to industrial application. Moreover, since the solvent is the reaction component with the highest concentration, competitive side-reactions such as
- hydrogen-atom transfer or solvolysis are often observed. A technological solution to cope with the Beer–Lambert law was offered by flow chemistry [19][20][21] by employing microreactors with reduced optical paths to enhance irradiation efficiency [22][23][24]. Photon-limited reactions, whose efficiency is
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