Vinylogous functionalization of 4-alkylidene-5-aminopyrazoles with methyl trifluoropyruvates

• Judit Hostalet-Romero,
• Laura Carceller-Ferrer,
• Gonzalo Blay,
• Amparo Sanz-Marco,
• José R. Pedro and
• Carlos Vila

Beilstein J. Org. Chem. 2025, 21, 533–540, doi:10.3762/bjoc.21.41

• functionalize 5-aminopyrazoles. Biologically active compounds featuring a trifluoromethyl carbinol motif. Nucleophilic sites of 5-aminopyrazoles and 4-alkenyl-5-aminopyrazoles. Stereoselective synthesis of trifluoromethyl carbinols through an vinylogous addition reaction of 4-alkenyl-5-aminopyrazoles to alkyl

Photomechanochemistry: harnessing mechanical forces to enhance photochemical reactions

• Francesco Mele,
• Ana M. Constantin,
• Andrea Porcheddu,
• Raimondo Maggi,
• Giovanni Maestri,
• Nicola Della Ca’ and
• Luca Capaldo

Beilstein J. Org. Chem. 2025, 21, 458–472, doi:10.3762/bjoc.21.33

• host to direct the photodimerization of 4.1 in a stereoselective fashion. The authors noted that, in stark contrast, the irradiation of 4.1 alone in a crystalline state yielded a mixture of isomers of 4.3 in low yield. Intriguingly, when a 4:1 ratio of 4.1 and 4.2 was used, 4.3 was obtained in 87

The effect of neighbouring group participation and possible long range remote group participation in O-glycosylation

• Rituparna Das and
• Balaram Mukhopadhyay

Beilstein J. Org. Chem. 2025, 21, 369–406, doi:10.3762/bjoc.21.27

• Rituparna Das Balaram Mukhopadhyay SWEET Lab, Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur, Nadia 741246, India 10.3762/bjoc.21.27 Abstract Stereoselective glycosylations are one of the most challenging tasks of synthetic

• to obtain the required stereoselective glycosylation is undeniably the most significant factor [49][50][51][52]. The role of participating and non-participating protecting groups shows contribution in shifting the SN1/SN2 spectrum interface of glycosylation, enabling the researchers to utilise them

• it to obtain significant stereoselective glycosylation products in good yields. Acetyl and benzoyl protection: The total synthesis of oligosaccharides has seen numerous illustrations of the participating role of the acyl esters. Citing a few references in order to elaborate the mechanistic protocol

Three-component reactions of conjugated dienes, CH acids and formaldehyde under diffusion mixing conditions

• Dmitry E. Shybanov,
• Maxim E. Kukushkin,
• Eugene V. Babaev,
• Nikolai V. Zyk and
• Elena K. Beloglazkina

Beilstein J. Org. Chem. 2025, 21, 262–269, doi:10.3762/bjoc.21.18

• was confirmed through the three-component reaction with acetylacetone, in which only the product 7 was formed (according to 1H NMR spectra of the reaction mixture). Stereoselective interactions between methylidene adducts and cyclopentadiene were confirmed for three-component reactions involving

Streamlined modular synthesis of saframycin substructure via copper-catalyzed three-component assembly and gold-promoted 6-endo cyclization

• Asahi Kanno,
• Ryo Tanifuji,
• Satoshi Yoshida,
• Sota Sato,
• Saori Maki-Yonekura,
• Kiyofumi Takaba,
• Jungmin Kang,
• Kensuke Tono,
• Koji Yonekura and
• Hiroki Oguri

Beilstein J. Org. Chem. 2025, 21, 226–233, doi:10.3762/bjoc.21.14

• of saframycin A (1) is assembled from two molecules of ʟ-tyrosine derivative 5 and peptidyl aldehyde 6 by non-ribosomal peptide synthetases (NRPS, Scheme 1a) [15][16][17][18][19][20][21]. The pivotal NRPS module, SfmC, catalyzes iterative regio- and stereoselective Pictet–Spengler (PS)-type

Recent advances in electrochemical copper catalysis for modern organic synthesis

• Yemin Kim and
• Won Jun Jang

Beilstein J. Org. Chem. 2025, 21, 155–178, doi:10.3762/bjoc.21.9

• catalytic systems (merging electrochemistry with transition-metal catalysis) has led to the development of new, efficient, and chemo- and stereoselective synthetic transformations. This review highlighted the recent developments in dual catalytic reactions involving copper and electrocatalysis, including C

Cu(OTf)₂-catalyzed multicomponent reactions

• Sara Colombo,
• Camilla Loro,
• Egle M. Beccalli,
• Gianluigi Broggini and
• Marta Papis

Beilstein J. Org. Chem. 2025, 21, 122–145, doi:10.3762/bjoc.21.7

• , also in regio- and stereoselective processes. The interest for these strategies arises from the cost-effectiveness as one-pot processes, the ease of application and the great efficiency when directed to the synthesis of biologically active compounds. Plausible general catalytic activation for ionic or

Recent advances in organocatalytic atroposelective reactions

• Henrich Szabados and
• Radovan Šebesta

Beilstein J. Org. Chem. 2025, 21, 55–121, doi:10.3762/bjoc.21.6

• ; Introduction Stereoselective catalytic formation of chiral compounds is one of the critical tasks of modern organic synthesis [1]. The catalytic formation of compounds with a center of chirality has been the focus of countless works and can now be considered a matured area. On the other hand, the generation of

• a CPA to be used as an organocatalyst or to a phosphoramidite to be used as a chiral ligand. Testing these new structures on known stereoselective transformations, the authors achieved high yields and enantioselectivities (up to 98% yield and 97% ee). Wang et al. performed asymmetric (4 + 3

Emerging trends in the optimization of organic synthesis through high-throughput tools and machine learning

• Pablo Quijano Velasco,
• Kedar Hippalgaonkar and
• Balamurugan Ramalingam

Beilstein J. Org. Chem. 2025, 21, 10–38, doi:10.3762/bjoc.21.3

• of stereoselective Suzuki–Miyaura couplings, offering precise control over both categorical and continuous variables (Figure 2a) [15]. The integrated robotic system containing a four-needle dispense head facilitated the delivery of reagents in low volume and slurries, ensuring the accuracy and

Non-covalent organocatalyzed enantioselective cyclization reactions of α,β-unsaturated imines

• Sergio Torres-Oya and
• Mercedes Zurro

Beilstein J. Org. Chem. 2024, 20, 3221–3255, doi:10.3762/bjoc.20.268

• -workers reported a cinchona alkaloid-derived thiourea-catalyzed regio- and stereoselective cycloaddition of 3-isothiocyanatooxindoles and imines containing two or three electron-deficient unsaturated bonds [25]. Firstly, the (3 + 2) cycloaddition of 3-isothiocyanatooxindoles 4 and aldimines 5 was explored

• -derived azadiene by H-bonding. This dual activation promotes a stereoselective addition of 3-chlorooxindole to the azadiene leading to intermediate A. The latter is also activated by the chiral guanidine and undergoes an intramolecular nucleophilic substitution which delivers the product 19b with the

• the bifunctional squaramide enables a stereoselective Michael addition of the azlactone to the azadiene forming intermediate A which transforms into intermediate B, which then undergoes an intramolecular cyclization to give the desired product 20. In 2020, Ni, Song and co-workers described a

Hypervalent iodine-mediated intramolecular alkene halocyclisation

• Charu Bansal,
• Oliver Ruggles,
• Albert C. Rowett and
• Alastair J. J. Lennox

Beilstein J. Org. Chem. 2024, 20, 3113–3133, doi:10.3762/bjoc.20.258

• from the styrenyl starting materials is stereoselective, giving the syn-diasteroisomer in high yields. A chiral iodoarene catalyst 16 was employed, along with a stoichiometric sacrificial oxidant, to give good to excellent levels of enantioselectivity. This elegant strategy led to a variety of β

Recent advances in transition-metal-free arylation reactions involving hypervalent iodine salts

• Ritu Mamgain,
• Kokila Sakthivel and
• Fateh V. Singh

Beilstein J. Org. Chem. 2024, 20, 2891–2920, doi:10.3762/bjoc.20.243

• products. The radical path was considered for the reaction mechanism as on adding TEMPO as radical scavenger the radical trapping adduct was detected by HRMS. Simultaneously with the above work, Murarka and co-workers also reported an organophotoredox-catalyzed stereoselective allylic arylation method for

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

• rearomatization In 2023, Lin and He et al. [72] achieved the challenging dearomatization of heteroarenes through d-orbital electron of the transition-metal center and thus completed the asymmetric substitutions with remote stereoselective control induced by alkynylcopper. A newly electron-rich ligand was

• structure precludes stable copper-carbonyl interaction, favoring attack from a less hindered site. Later, Qi and Xu et al. [75] achieved highly enantioselective copper-catalyzed [4 + 1] cyclization of yne-allylic esters and cyclic 1,3-dicarbonyls, achieving remote stereoselective control through copper

• 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

• strategically modifying LB substituents to induce asymmetry, a stereoselective catalytic scaffold was developed, favouring one enantiomer from both epoxide enantiomers. This work advances the in silico design of FLPs, highlighting their potential as asymmetric CCU catalysts with implications for optimising

• plot analysis reveals that the best candidate is F3_NB_C5_CF3, which is the catalyst based on the 2-borylbenzenamine scaffold, with a pyrrolidine substituent on the nitrogen atom and CF3 substituents on the boron. Through strategic modification of the Lewis base substituents, a stereoselective catalyst

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

• involves building a ring onto a preexisting system, whether cyclic or non-cyclic. The Lei group developed an electrooxidative annulation reaction that facilitates LSF [28]. A regio- and stereoselective protocol was established for the [4 + 2] annulation of indole derivatives, allowing access to highly

• mediator between the anode and the nickel-chelated enolate intermediate. Simultaneously, the amine substrate is oxidized at the anode and deprotonated to generate a nitrogen-centered radical. The desired product then is generated by the stereoselective cross-coupling of the carbon-centered radical with the

Phenylseleno trifluoromethoxylation of alkenes

• Clément Delobel,
• Armen Panossian,
• Gilles Hanquet,
• Frédéric R. Leroux,
• Fabien Toulgoat and
• Thierry Billard

Beilstein J. Org. Chem. 2024, 20, 2434–2441, doi:10.3762/bjoc.20.207

• the position of the double bond in the molecule. Notably, a longer reaction time was required for less reactive or more hindered substrates. The reaction was stereoselective as only the anti products were obtained. A good regioselectivity was generally observed, as at least 80% of the main regioisomer

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

• preparation of 2a. Moreover, the fact that only very limited examples are known for their synthetic application except for the synthesis of 4,4,4-trifluorothreonine [29][33], stereoselective ring opening with organometallic species [29], and so on [32] also stimulated our interest. In this article, we would

• successful employment of amines as nucleophiles for the epoxy ring opening in a highly stereoselective fashion, we next turned our attention to thiols. Optimization of the reaction conditions based on the ones for amines clarified the tendency that the longer reaction time and the higher temperature

• was confirmed as 2,3-anti-3,4-syn by its X-ray crystallographic analysis [49] (Figure 2) whose construction could be readily understood as the result of a highly stereoselective SN2-type epoxy ring opening of 2a, followed by the intramolecular lactone formation with the pro-R ethoxycarbonyl group

Stereoselective mechanochemical synthesis of thiomalonate Michael adducts via iminium catalysis by chiral primary amines

• Michał Błauciak,
• Dominika Andrzejczyk,
• Błażej Dziuk and
• Rafał Kowalczyk

Beilstein J. Org. Chem. 2024, 20, 2313–2322, doi:10.3762/bjoc.20.198

• significant advancement in mechanocatalysis. The stereoselective addition of bisthiomalonates 1–4 to cyclic enones and 4-chlorobenzylideneacetone proceeds stereoselectively under iminium activation conditions secured by chiral primary amines, in contrast to oxo-esters as observed in dibenzyl malonate addition

• studies by Bolm [12][13], and Juaristi et al. [14]. have significantly advanced chiral secondary amine-catalyzed stereoselective reactions under ball milling conditions, representing a widely explored activation mode in mechanochemical-mediated transformations. However, reports on chiral primary iminium

• attention. The controlled formation of C–C and C–X bonds in a stereoselective fashion has found extensive application in asymmetric synthesis. Notably, the addition of malonates has attracted significant interest, albeit primarily limited to methyl or ethyl diesters [18][19][20]. The combination of iminium

Diastereoselective synthesis of highly substituted cyclohexanones and tetrahydrochromene-4-ones via conjugate addition of curcumins to arylidenemalonates

• Deepa Nair,
• Abhishek Tiwari,
• Banamali Laha and
• Irishi N. N. Namboothiri

Beilstein J. Org. Chem. 2024, 20, 2016–2023, doi:10.3762/bjoc.20.177

• considerable interest in the stereoselective synthesis of the cyclohexanone skeleton as it constitutes the core structure in many natural products and pharmaceutical drugs [1][2]. Garsubellin A with a cyclohexanone skeleton is a potent inducer of choline acetyltransferase (ChAT) and could be used for the

Syntheses and medicinal chemistry of spiro heterocyclic steroids

• Laura L. Romero-Hernández,
• Ana Isabel Ahuja-Casarín,
• Penélope Merino-Montiel,
• Sara Montiel-Smith,
• José Luis Vega-Báez and
• Jesús Sandoval-Ramírez

Beilstein J. Org. Chem. 2024, 20, 1713–1745, doi:10.3762/bjoc.20.152

• steroidal 17-ketones were first alkylated in the presence of the lithium derivative of ethyl propiolate. After stereoselective formation of the corresponding adduct, the triple bond was chemoselectively reduced under catalytic hydrogenation using 5% palladium on charcoal. As a final step, a p

• ninhydrin. Estrone-derived dispiropyrrolidines 43, 44, and 45 were obtained in a regio- and stereoselective manner (ylide attacks by the α-steroidal face) in yields ranging from 66% to 72%. 1,3-Dipolar cyclization of azomethine ylides can also be achieved using (E)-steroidal arylidenes at C-16. In 2014, Liu

• superior results compared to phenyl-substituted compounds. Frank et al. synthesized a series of 16-spiroisoxazolines through a regio- and a highly stereoselective 1,3-dipolar cycloaddition between the double bond of the α,β-unsaturated steroidal ketone 73 and various arylnitrile oxides [45]. The reaction

Chemo-enzymatic total synthesis: current approaches toward the integration of chemical and enzymatic transformations

• Ryo Tanifuji and
• Hiroki Oguri

Beilstein J. Org. Chem. 2024, 20, 1693–1712, doi:10.3762/bjoc.20.151

• well as their analogs, is outlined with an emphasis on comparing these chemo-enzymatic syntheses with the corresponding natural biosynthetic pathways. Keywords: chemo-enzymatic synthesis; late-stage modification; reactive biosynthetic intermediate; regio- and stereoselective (macro)cyclization; total

• using an enzyme or at what stage in a synthesis the enzyme is employed: 1) regio- and stereoselective late-stage functionalization of core scaffolds, 2) in situ generation of highly reactive intermediates, and 3) the one-step construction of macrocyclic or fused multicyclic scaffolds via regio- and

• stereoselective cyclization reactions. This review aims to provide an overview of these approaches and parallel comparisons with original biosynthetic pathways by highlighting five examples of chemo-enzymatic total syntheses of natural products reported since 2017. The examples are the synthesis of cotylenol (1

Methyltransferases from RiPP pathways: shaping the landscape of natural product chemistry

• Maria-Paula Schröder,
• Isabel P.-M. Pfeiffer and
• Silja Mordhorst

Beilstein J. Org. Chem. 2024, 20, 1652–1670, doi:10.3762/bjoc.20.147

• within the context of ribosomally synthesised and post-translationally modified peptide (RiPP) natural products. Methyltransferases play a pivotal role in the biosynthesis of diverse natural products with unique chemical structures and bioactivities. They are highly chemo-, regio-, and stereoselective

Electrocatalytic hydrogenation of cyanoarenes, nitroarenes, quinolines, and pyridines under mild conditions with a proton-exchange membrane reactor

• Koichi Mitsudo,
• Atsushi Osaki,
• Haruka Inoue,
• Eisuke Sato,
• Naoki Shida,
• Mahito Atobe and
• Seiji Suga

Beilstein J. Org. Chem. 2024, 20, 1560–1571, doi:10.3762/bjoc.20.139

• semihydrogenation of alkynes to form Z-alkenes using a PEM reactor [31]. The Pd/C catalyst was essential for the reaction. They recently found that a PEM reactor with a Rh/C catalyst was effective for the stereoselective reduction of cyclic ketones [40]. Nagaki et al. reported the electrochemical deuteration of

Benzylic C(sp³)–H fluorination

• Alexander P. Atkins,
• Alice C. Dean and
• Alastair J. J. Lennox

Beilstein J. Org. Chem. 2024, 20, 1527–1547, doi:10.3762/bjoc.20.137

• ; however, the methodology was only shown on secondary benzylic positions. The stereoselective benzylic monofluorination of α-amino acids was also reported by Yu and co-workers, employing a similar directing group strategy (Figure 7) [41]. The use of the monodentate directing group 2,3,5,6-tetrafluoro-4

• was effective for the stereoselective fluorination of benzylic positions ortho to aldehyde substituents (Figure 9). The choice of a bulky amino, transient, directing group dictated the stereochemical outcome and promoted the C–F reductive elimination through an inner-sphere pathway. A competitive C–O

Towards an asymmetric β-selective addition of azlactones to allenoates

• Behzad Nasiri,
• Ghaffar Pasdar,
• Paul Zebrowski,
• Katharina Röser,
• David Naderer and
• Mario Waser

Beilstein J. Org. Chem. 2024, 20, 1504–1509, doi:10.3762/bjoc.20.134

• synthesis approaches. Our group has a longstanding focus on the development of asymmetric organocatalytic methods to access non-natural chiral α- and β-AA [14][15][16][17][18][19]. Hereby we are especially interested in utilizing simple (prochiral) starting materials and carry out stereoselective α