Influence of the cation in hypophosphite-mediated catalyst-free reductive amination

• Natalia Lebedeva,
• Fedor Kliuev,
• Olesya Zvereva,
• Klim Biriukov,
• Evgeniya Podyacheva,
• Maria Godovikova,
• Oleg I. Afanasyev and
• Denis Chusov

Beilstein J. Org. Chem. 2025, 21, 1661–1670, doi:10.3762/bjoc.21.130

• hypophosphorous acid are commercially available in bulk amounts, however, their usage is understudied in organic processes. While NaH2PO2 has proved to be an efficient four-electron reductant in the catalyst-free reductive amination, the influence of cation in hypophosphite salt has not been studied yet. This

• halogen atom transfer (XAT) agent [17][18]. Standard reduction potentials illustrate that hypophosphite is a powerful four-electron reductant [19]. Our previous studies have proved that NaH2PO2 can be a selective reducing agent in the catalyst-free reductive amination process [20][21][22] that can impart

Catalytic asymmetric reactions of isocyanides for constructing non-central chirality

• Jia-Yu Liao

Beilstein J. Org. Chem. 2025, 21, 1648–1660, doi:10.3762/bjoc.21.129

• ] involving 6-aryl-2-aminopyridines 27, aldehydes, and isocyanides (Scheme 5a) [35]. By employing chiral phosphoric acid (CPA) C1 as the catalyst, this reaction worked well to afford axially chiral imidazo[1,2-a]pyridines 28 in high-to-excellent yields (up to 99%) and enantioselectivities (up to >99% ee). It

• of the resulting products in developing chiral organocatalysts was investigated as well. For instance, 28a was converted to a thiourea-tertiary amine 29 through a four-step procedure in an overall 36% yield. This compound was then utilized as the catalyst in the electrophilic amination reaction

• condensation between 27 and the aldehyde afforded INT-A, which was activated by the CPA catalyst through hydrogen bonding interaction. The nucleophilic addition of isocyanide to Int-A produced INT-B bearing a stereogenic center. Subsequently, INT-B underwent intramolecular cyclization to generate axially

Formal synthesis of a selective estrogen receptor modulator with tetrahydrofluorenone structure using [3 + 2 + 1] cycloaddition of yne-vinylcyclopropanes and CO

• Jing Zhang,
• Guanyu Zhang,
• Hongxi Bai and
• Zhi-Xiang Yu

Beilstein J. Org. Chem. 2025, 21, 1639–1644, doi:10.3762/bjoc.21.127

• group in compound 10. Compound 10 can be realized by introducing an ester group in 9, which is the [3 + 2 + 1] cycloadduct from 8 and CO using a Rh catalyst. The [3 + 2 + 1] substrate of yne-vinylcyclopropane (yne-VCP) 8 can be synthesized by Wittig reaction from cyclopropyl aldehyde 7, in which the

• . Applying the traditional solvent dioxane for the [Rh(CO)2Cl]2 catalyzed [3 + 2 + 1] reaction (the catalyst loading was increased from 5 mol % to 10 mol %) gave 9 in only 26% yield. To our delight, the reaction yield could be improved to 87% by using mesitylene [30] as the solvent and the loading of [Rh(CO

• )2Cl]2 catalyst can be reduced to 3.6 mol % (the reaction scale was 20.6 mmol). After finishing the key [3 + 2 + 1] reaction, we focused on building the D ring in 1. Initially, we tried to directly close the ring through addition of the α position of the carbonyl group to the bridgehead vinyl group

Transition-state aromaticity and its relationship with reactivity in pericyclic reactions

• Israel Fernández

Beilstein J. Org. Chem. 2025, 21, 1613–1626, doi:10.3762/bjoc.21.125

• as the relative Lewis acidity of the catalyst (measured by the Child’s method [41][42][43]), but do not follow the same trend as the energy of the LUMO(dienophile). This finding therefore challenges the traditionally used LUMO-lowering concept as the ultimate factor controlling the catalysis in these

• LAs [66] (Table 2). As expected, we found that the reduction of the activation barrier (up to ca. 25 kcal/mol) directly correlates with the relative Lewis acidity of the catalyst. In addition, the process becomes more and more asynchronous as the acidity of the catalyst increases, which strongly

• significant reduction of the Pauli repulsion between the reactants in the catalyzed reaction. Therefore, once again we found that the LA catalyst induces a significant polarization in the reactive carbonyl group which (i) renders the process more asynchronous and therefore, less aromatic, but (ii) diminishes

3-Aryl-2H-azirines as annulation reagents in the Ni(II)-catalyzed synthesis of 1H-benzo[4,5]thieno[3,2-b]pyrroles

• Julia I. Pavlenko,
• Pavel A. Sakharov,
• Anastasiya V. Agafonova,
• Derenik A. Isadzhanyan,
• Alexander F. Khlebnikov and
• Mikhail S. Novikov

Beilstein J. Org. Chem. 2025, 21, 1595–1602, doi:10.3762/bjoc.21.123

• reaction. The highest yield of 3a (85%) was achieved by treating 1 with 3.2 equiv of the azirine in MeOH at 100 °С with 50 mol % of Ni(hfacac)2 (Table 1, entry 13). Lowering the temperature and the catalyst loading resulted in a slight deterioration in the yield and a significant slowing of the reaction

• -methylindole 9a with 2a, carried out in the presence of Ni(hfacac)2 (50 mol %), unfortunately, did not give any identifiable products. Experiments with the catalysts presented in Table 1 were also unsuccessful. Nevertheless, favorable outcomes were achieved through a substantial decrease in catalyst loading

Chemical synthesis of glycan motifs from the antitumor agent PI-88 through an orthogonal one-pot glycosylation strategy

• Shaokang Yang,
• Xingchun Sun,
• Hanyingzi Fan and
• Guozhi Xiao

Beilstein J. Org. Chem. 2025, 21, 1587–1594, doi:10.3762/bjoc.21.122

• in mannosyl PVB 8 (1.0 equiv) in the presence of TMSOTf as catalyst proceeded smoothly at 0 °C to room temperature, affording the α-Man-(1→3)-Man PVB disaccharide. The further coupling of the above PVB disaccharide with the poorly reactive 2-OH in mannoside 9 (0.9 equiv) under activation with NIS and

Azide–alkyne cycloaddition (click) reaction in biomass-derived solvent Cyrene^TM under one-pot conditions

• Zoltán Medgyesi and
• László T. Mika

Beilstein J. Org. Chem. 2025, 21, 1544–1551, doi:10.3762/bjoc.21.117

• formation; thus, keeping water content below 1% is necessary to maintain high reaction efficiency. The negative effect could be due to the decreased solubility of 2a at higher water content [42][43][44]. Hereafter, the readily available CuI was selected as a catalyst precursor to facilitate click reactions

• of volatile compounds from the aqueous phase by vacuum distillation, 88% of CyreneTM (13.7 g) was recovered. The reaction was repeated four times with the same procedure under identical conditions (same catalyst and substrate concentration). It was shown that CyreneTM could be successfully recovered

• , EtLev: ethyl levulinate, GVL: γ-valerolactone. Effect of the Cu source used in the click reaction of benzyl azide (1a, 1.15 mmol) and phenylacetylene (2a, 1 mmol). Reaction conditions: 2.5 mL CyreneTM, 1 mol % catalyst precursor, 0.1 mmol Et3N, T = 30 °C, t = 0.5 h. Copper-catalyzed azide–alkyne

General method for the synthesis of enaminones via photocatalysis

• Paula Pérez-Ramos,
• Raquel G. Soengas and
• Humberto Rodríguez-Solla

Beilstein J. Org. Chem. 2025, 21, 1535–1543, doi:10.3762/bjoc.21.116

• presence of amines and CuI as catalyst, as reported by Zhang and co-workers (Scheme 1B) [32]. On the other hand, Li et al. disclosed a silver-catalyzed amination of propargyl alcohols to afford enaminones (Scheme 1C) [33]. Although these new methods provide a wide variety of enaminones, there are

• the reactivity of unsaturated esters towards an aza-Michael addition is the use of transition metal complexes as catalysts/promoters [40][41][42]. Considering this background, we reasoned that Ni(II) could be a suitable catalyst for the amination of unsaturated systems. Initial investigations were

• adduct 10 was identified using GC–MS (Figure S1, Supporting Information File 1). When the reaction was performed under air-equilibrated conditions, the intended product 9a was obtained in a 31% yield, indicating that air influenced the interaction between the Ni-catalyst and the α,β-unsaturated carbonyl

Calcium waste as a catalyst in the transesterification for demanding esters: scalability perspective

• Anton N. Potorochenko and
• Konstantin S. Rodygin

Beilstein J. Org. Chem. 2025, 21, 1520–1527, doi:10.3762/bjoc.21.114

• acetylene production, was investigated. The catalyst was obtained by calcination of calcium carbide slag at 600 °C (CS600) and characterized by XRD and FTIR analysis. The transesterification reactions were carried out with primary alcohols, producing fatty acid alkyl esters in 51–99% yields, depending on

• the alcohols’ nature and catalyst amount (1–10 wt %). The CS600 catalyst demonstrated efficiency in the transesterification of low-molecular-weight esters, medium-chain triglycerides (C9–C12), and lactones, resulting in the corresponding methyl esters in 66–99% yields in the presence of low catalyst

• their manufacturing. The transesterification approach is an efficient way, which requires the use of a catalyst [44][45][46][47][48] and of course, there are many catalysts providing the desired transesterification products. However, the availability of the catalysts is limited, and the scope of

Photoredox-catalyzed arylation of isonitriles by diaryliodonium salts towards benzamides

• Nadezhda M. Metalnikova,
• Nikita S. Antonkin,
• Tuan K. Nguyen,
• Natalia S. Soldatova,
• Alexander V. Nyuchev,
• Mikhail A. Kinzhalov and
• Pavel S. Postnikov

Beilstein J. Org. Chem. 2025, 21, 1480–1488, doi:10.3762/bjoc.21.110

• experiment without a catalyst and observed only traces of the benzamide 2aa (Table 1, entry 1). However, we detected almost half of the salt 1a remained in the reaction medium after 10 hours of reaction (Supporting Information File 1, Figure S3). Thus, we settled with the similar conditions to the published

• . Unfortunately, 4CzTPN, 4CzIPN, and 3DPAFIPN did not demonstrate increased efficiency, and the yields of the target product 2aa were slightly lower than for [Ru(bpy)3](PF6)2 (Table 1, entries 4–6). Thus, all further optimization studies were done using [Ru(bpy)3](PF6)2 as a catalyst. After, we moved to the

• reactivity pattern in the current transformation, a reaction mechanism was proposed taking into the account the known data and control experiments (Scheme 4). Upon irradiation with blue light, the Ru(II) catalyst undergoes photoexcitation, followed by an oxidative single-electron transfer (SET) process with

Copper catalysis: a constantly evolving field

• Elena Fernández and
• Jaesook Yun

Beilstein J. Org. Chem. 2025, 21, 1477–1479, doi:10.3762/bjoc.21.109

• one of the most dynamic and versatile areas of contemporary chemical research. Once viewed primarily as a cost-effective alternative to noble metals, copper has emerged as a powerful and versatile catalyst, capable of mediating a wide array of chemical transformations through both two-electron and

• harness their Lewis-acidic and weakly oxidizing properties, respectively. In addition, microwave irradiation increases the reaction rate considerably. Furthermore, the use of a solid Cu(I) catalyst immobilized on an aminated silica support allows for a heterogeneous and cost-effective process, featuring

• straightforward workup and minimized free copper on solution. Due to this, the catalyst could be regenerated and reused in up to eight cycles. Upon optimization, this practical and versatile method could be used for the synthesis of several benzoxazole derivatives. A Letter was contributed by D’Andrea and Jademyr

Microwave-enhanced additive-free C–H amination of benzoxazoles catalysed by supported copper

• Andrei Paraschiv,
• Valentina Maruzzo,
• Filippo Pettazzi,
• Stefano Magliocco,
• Paolo Inaudi,
• Daria Brambilla,
• Gloria Berlier,
• Giancarlo Cravotto and
• Katia Martina

Beilstein J. Org. Chem. 2025, 21, 1462–1476, doi:10.3762/bjoc.21.108

• completed in 1.5–2 h. A solid Cu(I) catalyst supported on aminated silica made the process cost-effective and heterogeneous, thus simplifying work-up and minimising free copper in solution. The catalyst was found to be regeneratable and reusable for up to eight cycles. The optimised method facilitated the

• developed for the amination of oxazoles, with many of them utilizing aerobic oxidation to improve the sustainability of the process. Indeed, in 2011, Guo et al. [45] developed a protocol for the direct C–H amination of benzoxazoles and oxadiazoles, under an O2 atmosphere using 20 mol % of a Cu(II) catalyst

• being applied when reacting amides to achieve their decarbonylation. In 2014, Cao et al. [47] reported the amination of benzoxazole with a secondary amine either in air or an O2 atmosphere, lowering the catalyst amount and the reaction temperature. In 2020, a study by De Vos and co-workers [48] focused

Reactions of acryl thioamides with iminoiodinanes as a one-step synthesis of N-sulfonyl-2,3-dihydro-1,2-thiazoles

• Vladimir G. Ilkin,
• Pavel S. Silaichev,
• Valeriy O. Filimonov,
• Tetyana V. Beryozkina,
• Margarita D. Likhacheva,
• Pavel A. Slepukhin,
• Wim Dehaen and
• Vasiliy A. Bakulev

Beilstein J. Org. Chem. 2025, 21, 1397–1403, doi:10.3762/bjoc.21.104

• using [Cu(MeCN)4]OTf instead of Rh2(Piv)4, the target product 3aa was obtained in higher yield (72%, Table 1, entry 2) and with [Cu(MeCN)4]PF6, the yield of 1,2-thiazole 3aa increased to 82%, while the reaction time decreased significantly (Table 1, entry 3). Using Cu(OAc)2 as a catalyst led to a slight

• reaction did not occur. In the presence of metal catalyst PhINTs form a nitrenoid specie, containing electrophilic nitrogen. In metal-free conditions PhINTs participates in reactions as ylide with a nucleophilic nitrogen. We expected different reactivity of the two different forms of PhINTs. However, our

• expectations were not fulfilled. The exception is the data from entry 7 (Table 1), where the yield of compound 3aa was 78%. Thus, the conditions described in entry 7 (absence of a catalyst, use of 1.5 equiv of PhINTs 2a and dichloromethane (DCM) as a solvent at room temperature for 10 min) are optimal and were

High-pressure activation for the solvent- and catalyst-free syntheses of heterocycles, pharmaceuticals and esters

• Kelsey Plasse,
• Valerie Wright,
• Guoshu Xie,
• R. Bernadett Vlocskó,
• Alexander Lazarev and
• Béla Török

Beilstein J. Org. Chem. 2025, 21, 1374–1387, doi:10.3762/bjoc.21.102

• hydrostatic pressure (HHP) was found to be an efficient activation method in several catalyst- and solvent-free reactions and has found application for the syntheses of heterocycles and the preparation of active pharmaceutical ingredients (APIs) via acylation and acid- and solvent-free esterification. The

• reactions were carried out at ambient pressure (control) and under HHP (up to 3.8 kbar) conditions. These representative reactions provided higher yields for the products and HHP enabled truly green processes that are catalyst- and solvent-free, to occur with high yields and producing only non-toxic by

• -products. A computational study accompanies the experimental data to interpret the outcome of the reactions. Keywords: acetaminophen; acetylsalicylic acid; benzimidazoles; catalyst-free synthesis; cyclization; esters; high hydrostatic pressure; pyrazoles; Introduction Non-traditional activation methods

Oxetanes: formation, reactivity and total syntheses of natural products

• Peter Gabko,
• Martin Kalník and
• Maroš Bella

Beilstein J. Org. Chem. 2025, 21, 1324–1373, doi:10.3762/bjoc.21.101

• alcohols 13 and a binary Al/TBAB catalyst (Scheme 5) [40]. The reaction is carried out in toluene upon mild heating, providing the bicyclic products in high to excellent yields. Both electron-rich and electron-poor phenyls as well as aliphatic chains worked well, however, increased temperature and catalyst

• /RPC mechanism starts with a single-electron oxidation of the cobalt catalyst followed by a reaction with the siloxane to generate a cobalt–hydride complex. Subsequent hydride transfer to the alkene produces radical pair 23 which collapses to alkylcobalt intermediate 24. Another single-electron

• oxidation of the metal centre turns the cobalt into an excellent leaving group, allowing for an intramolecular displacement reaction that affords the oxetane ring and regenerates the Co(II) catalyst. In 2023, Silvi et al. described a versatile and practical methodology that couples Williamson etherification

Recent advances in amidyl radical-mediated photocatalytic direct intermolecular hydrogen atom transfer

• Hao-Sen Wang,
• Lin Li,
• Xin Chen,
• Jian-Li Wu,
• Kai Sun,
• Xiao-Lan Chen,
• Ling-Bo Qu and
• Bing Yu

Beilstein J. Org. Chem. 2025, 21, 1306–1323, doi:10.3762/bjoc.21.100

• -Alkylbenzamide constitutes the primary structural unit of this class of compounds. The structures of these compounds are relatively simple and readily synthesizable. In these photocatalytic systems, direct single-electron oxidation of the amide HRP occurs in the presence of a photoredox catalyst and a base via a

• carbanion, which undergoes either solvent-mediated protonation or direct proton transfer from the acridiniumamide, ultimately delivering product 89 while regenerating the zwitterionic HRP-12 catalyst. This catalytic platform demonstrated exceptional site selectivity in aliphatic C–H bromination under

Recent advances and future challenges in the bottom-up synthesis of azulene-embedded nanographenes

• Bartłomiej Pigulski

Beilstein J. Org. Chem. 2025, 21, 1272–1305, doi:10.3762/bjoc.21.99

• azulene-embedded PAHs. This approach requires a halogen-functionalized precursor and typically employs a palladium catalyst. Dou and co-workers reported a last-stage intramolecular C–H arylation of substituted indenofluorenes 61 and 62 (Scheme 10) [57]. The palladium-catalysed reaction yielded fused

• Pd catalyst pathway. Both 121 and 122 exhibit typical azulene-like red-shifted absorption due to almost forbidden S0→S1 transition. Liu and co-workers reported also an isomer of bischrysene containing two azulene subunits (Scheme 16) [79]. Precursor 125 was obtained through PtCl2-catalysed

Recent advances in oxidative radical difunctionalization of N-arylacrylamides enabled by carbon radical reagents

• Jiangfei Chen,
• Yi-Lin Qu,
• Ming Yuan,
• Xiang-Mei Wu,
• Heng-Pei Jiang,
• Ying Fu and
• Shengrong Guo

Beilstein J. Org. Chem. 2025, 21, 1207–1271, doi:10.3762/bjoc.21.98

• equimolar amount of tert-butyl hydroperoxide (TBHP) as the oxidant, with the reaction conducted at 100 °C under an argon atmosphere, resulting in a 79% yield of the desired product 7a without the requirement for any metal catalyst. In terms of substrate scope, the study explored various N-arylacrylamides

• the alkyl source was presented, providing a novel and efficient route to 3,3-dialkylated oxindoles [7]. In this system, Cu2O was used as the catalyst, combined with dicumyl peroxide (DCP) as the oxidant, in ethyl acetate (EtOAc) at 120 °C under an argon atmosphere. This reaction efficiently produced

• radical-mediated process. The necessity of Cp2Fe and Y(OTf)3 for the reaction was also confirmed, as the absence of either catalyst led to a dramatic decrease in product yield. These findings highlighted the critical role of electrochemically generated carbon-centered radicals in driving the cyclization

Synthesis of β-ketophosphonates through aerobic copper(II)-mediated phosphorylation of enol acetates

• Alexander S. Budnikov,
• Igor B. Krylov,
• Fedor K. Monin,
• Valentina M. Merkulova,
• Alexey I. Ilovaisky,
• Liu Yan,
• Bing Yu and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2025, 21, 1192–1200, doi:10.3762/bjoc.21.96

• , which generally employed stoichiometric amounts of oxidants or more expensive transition metal catalysts, the present protocol employs only cheap copper sulfate pentahydrate as a catalyst under mild reaction conditions. The achieved phosphorylation proceeds via the formation of P-centered radicals

• reaction times, and scope limitations. In the present work, the selective copper(II)-mediated phosphorylation of enol acetates with the formation of substituted β-ketophosphonates employing cheap copper sulfate as a catalyst and atmospheric oxygen as a terminal oxidant was carried out (Scheme 1c). Results

• the desired product only in trace amounts (Table 1, entry 3). The optimal loading of the catalyst was examined (Table 1, entry 4); the best results were obtained with 20 mol % of copper sulfate, slightly lower yield (64%) was observed with 10 mol % loading of the catalyst. Increased temperature was

Enhancing chemical synthesis planning: automated quantum mechanics-based regioselectivity prediction for C–H activation with directing groups

• Julius Seumer,
• Nicolai Ree and
• Jan H. Jensen

Beilstein J. Org. Chem. 2025, 21, 1171–1182, doi:10.3762/bjoc.21.94

• . Nevertheless, the high prevalence of C–H bonds in organic compounds presents a substantial challenge in achieving site-specific functionalization. A principal strategy to circumvent this challenge leverages directing groups (DGs) within the substrate, which coordinate to the metal centre of the catalyst

• , thereby dictating the site of C–H activation. Common DGs include unsaturated heteroatoms and alkenyl groups, which have proven effective in guiding the regioselectivity of these reactions [4]. Mechanistic studies with palladium(II) acetate (Pd(OAc)2) as catalyst support the following mechanism of C–H

• activation, called concerted metal deprotonation (CMD) [5][6][7]. In a concerted mechanism, the Pd atom of the catalyst forms a sigma bond to an aromatic carbon, which increases the acidity of the adjacent (alpha) proton. This allows for the simultaneous abstraction of this proton by a carboxylate ligand. A

A multicomponent reaction-initiated synthesis of imidazopyridine-fused isoquinolinones

• Ashutosh Nath,
• John Mark Awad and
• Wei Zhang

Beilstein J. Org. Chem. 2025, 21, 1161–1169, doi:10.3762/bjoc.21.92

• initial GBB reaction of aminopyridines 1 (0.5 mmol), isocyanides 3 (1.2 equiv), and furfuraldehydes 2 (1.2 equiv) was conducted in 3:1 CH2Cl2/MeOH (4 mL) using Yb(OTf)3 (0.08 equiv) as a Lewis acid catalyst under microwave irradiation at 100 °C for 1 h (Scheme 2). Nineteen distinct adducts 4 were obtained

• isoquinolinones 8 was explored by conducting IMDA and spontaneous dehydrative re-aromatization reactions. The IMDA reaction using 6a as a model compound was systematically evaluated by varying catalysts, solvents, reaction temperatures and times (Table 1). The best conditions were found to use AlCl3 as a catalyst

• , indicating a smooth transition from the transition state to the product. The final dehydrative ring-opening gives products by decreasing the energy to 0.978 kJ/mol. Computational analysis indicates that the IMDA step has a high energy barrier which needs a catalyst, while the dehydrative re-aromatization

Synthetic approach to borrelidin fragments: focus on key intermediates

• Yudhi Dwi Kurniawan,
• Zetryana Puteri Tachrim,
• Teni Ernawati,
• Faris Hermawan,
• Ima Nurasiyah and
• Muhammad Alfin Sulmantara

Beilstein J. Org. Chem. 2025, 21, 1135–1160, doi:10.3762/bjoc.21.91

• -substituted acrylic acid 51 (Scheme 7). After optimization, the iridium complex (Ra)-50, in the presence of cesium carbonate, was identified as the most efficient catalyst, producing compound 52 in 97% yield with an enantiomeric excess of 97.6%. Subsequently, compound 52 was treated with Meldrum’s acid in the

• . Starting from ent-52, obtained via the asymmetric hydrogenation of 51 using the catalyst (Sa)-50, the previously developed three-steps reaction sequence was adopted and repeated three times, yielding polydeoxypropionic acid 57 in an overall yield of 54%. The iridium catalyst (Ra)-50 was chosen to ensure

• the syn-product 96a in 90% yield with a diastereomeric ratio of 98:2. Interestingly, substituting the catalyst with ent-94 delivered 96b in 89% yield and dr 95:5. Subsequently, 96a was subjected to a similar sequence of reduction, HWE olefination, asymmetric 1,4-addition, culminating in compound 98 in

A versatile route towards 6-arylpipecolic acids

• Erich Gebel,
• Cornelia Göcke,
• Carolin Gruner and
• Norbert Sewald

Beilstein J. Org. Chem. 2025, 21, 1104–1115, doi:10.3762/bjoc.21.88

• solvents. Table 1 provides an overview (a more detailed table can be found in Supporting Information File 1), which catalysts and bases are showing the best results. Most of the bases did not change the conversion drastically, apart from Et3N, which shows the least conversion regardless of the catalyst

• performance to Cs2CO3 including the lack of methyl ester hydrolysis, but a lower price. The catalyst's performance had a more significant influence on the reaction results than the base. Both phosphine catalysts as well as the second generation of the Buchwald–Hartwig catalyst [47][48] gave similar results

• , the best results were achieved with Pd(dppf)Cl2. The conversion was among the highest overall regardless of base and the removal of the catalyst afterwards was most straightforward. While the phosphine-based catalysts tend to be oxidised during the workup, resulting in the contamination of the

Salen–scandium(III) complex-catalyzed asymmetric (3 + 2) annulation of aziridines and aldehydes

• Linqiang Wang and
• Jiaxi Xu

Beilstein J. Org. Chem. 2025, 21, 1087–1094, doi:10.3762/bjoc.21.86

• uses readily available components. On the basis of the experimental results and a previous report [16], a possible reaction mechanism is presented in Scheme 3. The catalyst (Cat) is first generated from salen L1 and Sc(OTf)3. Aziridines 1 coordinate to the Sc ion in the catalyst with their two

• of the catalyst for the next catalytic cycle. The electron-deficient aromatic aldehydes exhibit excellent stereoselectivity due to the π-stacking interaction between their aryl group and the electron-rich malonate group. Similar π-stacking interaction-controlled stereoselectivities were observed in

• method uses readily available salen as chiral ligand, which coordinates with scandium triflate to generate a salen–Sc complex acting as efficient catalyst. The catalytic asymmetric (3 + 2) annulation of dialkyl 3-aryl-1-sulfonylaziridine-2,2-dicarboxylates and aldehydes generated optically active

Recent advances in synthetic approaches for bioactive cinnamic acid derivatives

• Betty A. Kustiana,
• Galuh Widiyarti and
• Teni Ernawati

Beilstein J. Org. Chem. 2025, 21, 1031–1086, doi:10.3762/bjoc.21.85

• yield. The reaction proceeds via a CeO2-coordinated carboxylate mode (Scheme 31A) [67]. In addition, the catalyst also offered high reusability for up to 4 runs thus further promoting the eco-friendliness. Carbonyl activation via Lewis acid–O=C interaction has also been achieved using other transition

• group (2024) also investigated BH3·pyridine to catalyze amidation reactions with lower catalyst loading (Scheme 40B) [77]. Whiting and co-workers (2019) also used boranes to catalyze the direct amidation of carboxylic acids. In this work, they co-polymerized styrene, divinylbenzene and

• vinylphenylboronic acid to synthesize the solid-supported phenylboronic acid catalyst (cat 1) which was used to convert cinnamic acid (7) to its corresponding amide 12 in moderate yield. The reaction involves dicarboxylate complex 135 formed through Lewis acid B–O=C interaction (Scheme 41A) [23]. The catalyst could