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Search for "addition" in Full Text gives 3210 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.
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
- ]. The limited investigation of allene hydrocyanation can be attributed to the significant challenges posed by the two orthogonal π-systems in allenes. These challenges include achieving high regioselectivity and controlling (E)/(Z)-stereoselectivity, as 1,2-addition processes to allenes can generate up
- , the hydride addition of DIBAL-H to allene 1a catalyzed by 5 mol % IPrCuCl as the optimal catalyst selectively generated the allylaluminum intermediate 2a with >98% conversion [30]. Subsequent addition of one equivalent of TsCN to 2a in a single vessel at room temperature proceeded regioselectively
- , achieving complete conversion within 30 min and yielding the desired α-quaternary nitrile 3a in 95% yield. Moreover, no byproducts, such as regioisomeric nitriles or derivatives from over-addition of allylaluminum, were observed. After having established the optimized reaction conditions, the substrate
Carbon-rich materials: from polyaromatic molecules to fullerenes and other carbon allotropes
Beilstein J. Org. Chem. 2025, 21, 798–799, doi:10.3762/bjoc.21.62
- ; polyaromatic molecules; In addition to diamond and graphite, traditional carbon allotropes in our old high-school textbook, new types of carbon allotropes, molecular carbons, were discovered in the last decades. These include fullerenes (1985) [1], carbon nanotubes (1991) [2], and graphene (2004) [3]. Due to
Recent advances in the electrochemical synthesis of organophosphorus compounds
Beilstein J. Org. Chem. 2025, 21, 770–797, doi:10.3762/bjoc.21.61
- that controls reaction selectivity by adjusting voltage or current [13]. Simple synthetic systems in electrochemical methods are limited to electrodes, cells, electrolytes, and power supplies. Today, in addition to the above, light, metallic, and organic catalysts are also used to increase the
- experiments, the oxidation current increased further with the addition of diphenylphosphine oxide to the mixture of Mn(OAc)2 and 2,2-bipyridine. This suggests that 2,2-bipyridine likely influenced the oxidation of Mn(II) and reacted with diphenylphosphine oxide. Further studies have also shown that the
- performed in the presence of TEMPO, the product of TEMPO-P(O)R2 was formed, which showed that the process proceeded through a radical path. In addition, the reaction was carried out in an electrochemical environment with an undivided cell, using graphite and platinum plate electrodes as the anode and
New advances in asymmetric organocatalysis II
Beilstein J. Org. Chem. 2025, 21, 766–769, doi:10.3762/bjoc.21.60
- describes the enantioselective Michael addition of pyrazoline-5-ones to α,β-unsaturated ketones. The enantioselectivity and chemical efficiency of this transformation were achieved with a cinchona-alkaloid-derived primary-amine–Brønsted acid composite [22]. A good demonstration of how organocatalysis
- ]. The enantioselective addition of propargyltrichlorosilane to aldehydes was studied by Prabhakar, Takenaka, and co-workers. This transformation was catalyzed by a biisoquinoline N,N’-dioxide catalyst, which acted as a chiral Lewis base [26]. Torres-Oya and Zurro reviewed the recent developments in
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
- cyanide source. This observation complies with the results from the computational study (Figure 2). In addition, some TMSCN is consumed together with an amount of BINOL phosphate through the probably parasitic formation of catalytically inactive trimethylsilyl phosphate 3a, which we were able to
- our previous work [45], we carried out the enantioselective hydrocyanation of hydrazones using Ca–BINOL phosphate complex 6 at −10 °C in DCM for 72 h. In addition to those reaction conditions, we initially used t-BuOH as an additive [45]. The Ca–BINOL phosphate complex 6 was prepared in situ by
Copper-catalyzed domino cyclization of anilines and cyclobutanone oxime: a scalable and versatile route to spirotetrahydroquinoline derivatives
Beilstein J. Org. Chem. 2025, 21, 749–754, doi:10.3762/bjoc.21.58
- into tetrahydroquinoline (THQ)-based 6-6-4-membered ring systems through a combination of nucleophilic addition and borate-mediated [2 + 2] photocycloaddition, offering a catalyst-free approach to construct conformationally constrained 2D/3D frameworks with high functional group compatibility and
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
- and tested to investigate the details of carbohydrate recognition [1][2][3][4][5][6][7]. It has turned out that carbohydrate–lectin interactions are orchestrated by a multitude of structural parameters. In addition to the configurational characteristics of specific carbohydrate building blocks, homo
- with FimH (Supporting Information File 1, Figures S19–S21). In addition to the π–π interaction of the CRD-bound mannose-projecting antenna of the EE isomer with Tyr48, the complex is stabilized by hydrogen bonds of the scaffold mannoside to Tyr48 and in case of the glucose moiety to Thr51, Ile52, and
- like glycoclusters 1 and 2 are capable of many conformational alternatives and therefore, the control of molecular shape by photoisomerization of azobenzene linkers has its limitations. In addition, water solubility requires improvement. Furthermore, our study, combining synthesis, analysis of
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
- and iodine, respectively, were applied to compound 5 to give the chloropropyl and iodopropyl HBC dyes 12 and 13 (Scheme 4). In addition, the HBC alcohol 5 was reacted under basic conditions with methanesulfonyl chloride to give the N-(3-mesyloxypropyl) HBC derivative 14, or with tosyl chloride to give
- counterpart. The tosyloxypropyl HBC analog 15 was also less reactive than its bromo counterpart. Of all the HBC dyes with reactive handles synthesized to date, the highest RNA alkylation yield was obtained with the N-(3-mesyloxypropyl) HBC derivative 14. In addition, the mesyl compound 14 showed significantly
- in 40 µL of water, followed by the addition of 12 µL of buffer (250 mM HEPES, 500 mM KCl, pH 7.0) and 6.0 µL of MgCl2 solution (20 mM). The aptamer was annealed by heat shock at 90 °C for 2 minutes and cooled on ice. Then, 2.0 µL of a ligand stock solution (3.0 mM, in DMSO) was added. The final
Acyclic cucurbit[n]uril bearing alkyl sulfate ionic groups
Beilstein J. Org. Chem. 2025, 21, 717–726, doi:10.3762/bjoc.21.55
- , 10 min). The crude solid was analyzed by 1H NMR which showed residual pyridine. The crude solid was subsequently dissolved in water (150 mL) and re-precipitated by the addition of EtOH (144 mL) followed by centrifugation (7200 rpm, 5 min) to obtain a white solid. The solid was dried overnight under
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
- vs axial). Normally, the pucker with an equatorial carboxyl group is favoured. This pucker is maintained in the difluorinated analogue 97 (Figure 11); in this conformation, in addition to the favourable equatorial placement of the carboxyl group, all of the interactions I–III (Figure 11) are
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
- ]. Also, the effects of fluorination on the chiroptical features of [n]helicenes were theoretically predicted [41]. In addition to the manipulation of electronic natures, partial fluorination of PAHs has been recognized to be significant for crystal design and engineering. Thus, molecular packing patterns
- progression. The first phosphorescence vibrational peak was observed at 501 nm for PIC and 514 nm for FUL [48]. In the case of F8-phenacenes, at 77 K, in addition to fluorescence bands, photoluminescence bands assignable to phosphorescence were detected (λPHOS = 518 nm for F8PIC, 528 nm for F8PIC, and 525 nm
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
- chiral nickel complexes. In recent years, the Soloshonok working group demonstrated the synthesis of non‑natural amino acids using the corresponding chiral Ni(II) complex [7]. In addition to the high enantiomeric purity of the corresponding products, the scale of the reaction, which extends into the
Recent advances in allylation of chiral secondary alkylcopper species
Beilstein J. Org. Chem. 2025, 21, 639–658, doi:10.3762/bjoc.21.51
- importance of reaction conditions after ZnCl2 addition (Scheme 5). When the reaction mixture was stirred at −30 °C for 1 hour (entry 1 in Scheme 5), the product 19 maintained a high diastereomeric ratio (dr), indicating minimal racemization. However, extending the stirring time or increasing the reaction
- optimization revealed LiOt-Bu and diphenyl phosphate as the optimal metal alkoxide and leaving group, delivering the desired product 32 in high yield and high enantioselectivity at room temperature with only 2 mol % catalyst loading. The scope of this transformation proved to be remarkably broad. In addition
- traditional crotyl addition to acetaldehyde. This methodology represents the first example of highly enantio- and diastereoselective copper-catalyzed allylic substitution that controls vicinal stereogenic centers. DFT calculations revealed that the high enantioselectivity (98:2 er) originates from a face
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
- , and afforded trace amounts of 6h together with the corresponding acyclic hemiaminal 10h as the major product. Such an outcome can be attributed to a slower formation of a 6-membered ring [15] from transient N-acyliminium species. Gratifyingly, the addition of KOH (1 equiv) to the electrolysis mixture
- facilitated the cyclization, and the 6-membered heterocycles 6h,i could be obtained in 27% and 18% yield, respectively. In addition to sulfonamides, carbamates such as N-Boc and benzamide are also suitable as nucleophiles for the anodic decarboxylation/cyclization reaction. However, the corresponding 2
- -aminoproline derivatives 6j,k were obtained in considerably lower yields (38%) as compared to those of N-Ts analog 6a. Surprisingly, the addition of KOH (0.5 equiv) to the electrolysis solution has helped to improve yield of N-Boc-protected 2-aminoproline derivative 6j from 38% to 59%. However, the addition of
Photocatalyzed elaboration of antibody-based bioconjugates
Beilstein J. Org. Chem. 2025, 21, 616–629, doi:10.3762/bjoc.21.49
- functionalized nature of polypeptides/proteins demands exquisite selectivity to target specific sites on the macromolecule of interest. In addition to the requisite features of the chemical methods outlined above, there are key requirements for synthetic methods used in ADCs, which include high site-selectivity
- particularly useful and important tool in which azides and other dipolar species engage with reactive alkenes and alkynes on non-canonical amino acids [20]. Transition-metal-mediated processes, including metathesis reactions, aryl cross-coupling reactions, and conjugate addition reactions with dehydroalanine
- transformations is a strong electrophile that can react with Tyr, for instance, if such an amino acid is located near the reactive site. In addition, command of the DAR might have some limits, as the distance between the catalyst and the mAbs is not well defined, meaning that the photoredox reaction might not
Semisynthetic derivatives of massarilactone D with cytotoxic and nematicidal activities
Beilstein J. Org. Chem. 2025, 21, 607–615, doi:10.3762/bjoc.21.48
- % yield) obtained as a white powder. Its molecular formula C27H31ClO10 was deduced from the HRESIMS spectrum (Figure S2, Supporting Information File 1), which exhibited the sodium adduct at m/z 573.1495 (calcd. for C27H31ClO10Na+: 573.1498) and NMR analysis. In addition to resonances attributed to
- the presence of catalytic amounts of 4-dimethylaminopyridine, 82% yield) was proposed as C32H23Br3O9 based on the molecular ion cluster sodium adducts [M + Na]+ depicted at m/z 810.96, 812.94, 814.92, and 816.90 characteristic for the presence of three bromine atoms [22]. In addition to signals
- Information File 1) which showed the protonated molecular ion peak and the sodium adduct at m/z 325.1281 [M + H]+ (calcd. for C16H21O7+: 325.1282) and 347.1103 (calcd. for C16H20O7Na+: 347.1101), respectively. Its 1HNMR spectrum displayed in addition to signals ascribed to massarilactone D, those of a
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
- acidic conditions as key step to construct an aryl-containing quaternary center. The 6/5/6 benzofuran unit was formed through reductive elimination with Zn/AcOH and a spontaneous oxy-Michael addition. This synthesis consists of 8 steps and achieves an overall yield of 13%, making it the shortest known
- construct the aryl and allyl-containing quaternary center, and a simultaneous phenol-initiated oxy-Michael addition to afford the benzofuran unit. This synthesis took 9 steps and achieved an overall yield of 13%. Also in 2024, the Denton group reported another efficient way to access the 6/5/6 benzofuran
- scaffold of simonsol C, utilizing an alkaline dearomatization as the key reaction, followed by a functional-group-selective Wittig reaction and concurrent oxy-Michael addition [6]. A bromophenol acetal was used in the intramolecular alkylative dearomatization, which was first reported by Magnus et al. [8
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
- 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
- second step was attempted as part of a one-pot synthesis of hydantoins by the addition of concentrated hydrochloric acid followed by microwave irradiation of the reaction mixture at 80 °C for 15 min (Scheme 2). Gratifyingly, the acid-induced intra-cyclization of the urea derivative H1a proceeded smoothly
- ][15][16], but reaction times are significantly shorter. In addition, TLC analysis confirmed complete consumption of starting material, which was further confirmed by NMR analysis showing no detectable impurities or unreacted starting material. Variations in yields (34–89%) may be due to differences in
Formaldehyde surrogates in multicomponent reactions
Beilstein J. Org. Chem. 2025, 21, 564–595, doi:10.3762/bjoc.21.45
- decompose into DMS (dimethyl sulfide), which then can act as a nucleophile in several MCRs (Scheme 4) [19][20][21][22]. In this context, DMSO can be used as a source of the methylsulfanyl (-SCH3) group after DMS follows a nucleophilic addition or substitution, allowing one to obtain different types of
- nucleophilic species present in the reaction medium, MMS can act as a methylene source. Under hydrolysis conditions, it can be a source of formaldehyde (Scheme 5a), but with other nucleophiles, after nucleophilic addition, the sulfide group can work as a leaving group, allowing for a sequential domino process
- developed in which the alkene compound has been replaced with other surrogates for electrophilic addition, such as ketones [32][33][34]. In the case of the carbonyl component, it is generally an aromatic aldehyde [30][33][34] and there are not many reports on using formaldehyde in the Povarov reaction. In a
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
- 4). The suggested method allows one to utilize arylhydrazines both with donor and acceptor substituents in the aromatic ring. Besides that, heterocyclic hydrazines also can be used in the considered transformation. In addition, we have tried to carry out the process under investigation with
- established by X-ray analysis. The proposed mechanism of the considered processes is outlined at Scheme 8. Initially, the free nitrogen nucleophile is reversibly generated from the corresponding hydrochloride or acetate. Next, acid-catalyzed addition of the amine component to the carbon atom of the aroyl
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
- 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
- amide moiety and with almost no enantioselectivity. Although the addition of a catalytic amount of 9e accelerated the reaction, the same diastereomer of 17b as the major product was obtained as for the reaction without a catalyst, which shows the importance of halonium salt moieties in our catalysts
Binding of tryptophan and tryptophan-containing peptides in water by a glucose naphtho crown ether
Beilstein J. Org. Chem. 2025, 21, 541–546, doi:10.3762/bjoc.21.42
- moiety in the amino acid. This hypothesis is also supported by the significant quenching of the fluorescence of the naphthalene unit in 1 upon addition of increasing amounts of H-Trp-OH to the solution. Additionally, cation–π interactions between the ammonium cation of the guest and the naphthalene of
- fluorescence measurements where a strong quenching of the naphthalene fluorescence upon addition of each of the Trp-containing tripeptides 2–7 was observed. For peptides 2 and 3 interactions of the receptor with the N-terminal ammonium cation are likely also involved in the binding process (Figure 5). This is
- – a chemoselective receptor for aromatic amino acid esters in water. Fluorescence emission spectra of receptor 1 (25 μM in H2O) upon addition of increasing amounts of tripeptide 2. The concentration of the guest corresponding to each curve is indicated on the right. The arrow marks the quenching of
Vinylogous functionalization of 4-alkylidene-5-aminopyrazoles with methyl trifluoropyruvates
Beilstein J. Org. Chem. 2025, 21, 533–540, doi:10.3762/bjoc.21.41
- Judit Hostalet-Romero Laura Carceller-Ferrer Gonzalo Blay Amparo Sanz-Marco Jose R. Pedro Carlos Vila Departament de Química Orgànica, Facultat de Química, Universitat de València, Dr Moliner 50, 46100 Burjassot, València, Spain 10.3762/bjoc.21.41 Abstract A valuable vinylogous addition reaction
- 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
Deep-blue emitting 9,10-bis(perfluorobenzyl)anthracene
Beilstein J. Org. Chem. 2025, 21, 515–525, doi:10.3762/bjoc.21.39
- ANTH and the –C6F5 group might provide the desired spatial isolation of the ANTH (and other PAH) cores, and result in enhanced photoluminescence by disrupting close π–π stacking in the solid state. In addition, air- and photostability might also be improved due to the steric and electronic properties
- of multiple BnF substituents. For example, C5-pentakis(BnF)corannulene (C5-CORA(BnF)5) [18][19] exhibited improved acceptor strength relative to unsubstituted CORA due to the electron-withdrawing BnF groups (which are similar to the electron-withdrawing properties of CF3 groups [18][19]). In addition
- reactions) Dry Mg turnings (excess) were added to an oven-dried 100 mL Schlenk flask and mechanically activated via stirring and heating. After 1 h, dry THF (20 mL) and 9,10-ANTH(Br)2 (84 mg, 0.25 mmol) were added. Several activation methods were tried (ultra sonic bath, careful heating, addition of I2
Synthesis of the aggregation pheromone of Tribolium castaneum
Beilstein J. Org. Chem. 2025, 21, 510–514, doi:10.3762/bjoc.21.38
- has been found to damage 246 grain commodities, especially starchy products [2][3]. In addition, the adult T. castaneum secretes carcinogenic methyl-1,4-benzoquinone and ethyl-1,4-benzoquinone to inhibit the microorganisms and the predators [4][5]. Therefore, T. castaneum infected stored products are
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