Design and synthesis of an axially chiral platinum(II) complex and its CPL properties in PMMA matrix

• Daiki Tauchi,
• Sota Ogura,
• Misa Sakura,
• Kazunori Tsubaki and
• Masashi Hasegawa

Beilstein J. Org. Chem. 2026, 22, 143–150, doi:10.3762/bjoc.22.7

• chiral platinum(II) complex was synthesized via Sonogashira coupling and subsequent coordination of a pincer ligand to a precursor. The complex exhibited a broad absorption band ranging from 250 to 550 nm in the UV–vis spectrum, with TD-DFT calculations indicating mixed ligand-to-ligand charge transfer

• two platinum(II) chromophore units, leading to the chiroptical properties in the MLCT region through exciton coupling under restricted molecular motion. Keywords: axial chirality; chiral chemistry; circularly polarized luminescence (CPL); phosphorescence; platinum(II) complex; Introduction

• , pincer-type platinum(II) complexes have attracted particular attention, owing to the structural robustness imparted by tridentate chelating ligands and their excellent luminescent properties [12][13][14][15][16][17]. These complexes have been widely investigated, not only for practical application but

Total synthesis of natural products based on hydrogenation of aromatic rings

• Haoxiang Wu and
• Xiangbing Qi

Beilstein J. Org. Chem. 2026, 22, 88–122, doi:10.3762/bjoc.22.4

• -art systems depend on expensive transition metals such as platinum, ruthenium, or palladium, inflating the cost of large-scale applications. In addition, precious-metal catalysts often display poor selectivity, while heteroatoms in heteroarenes – acting as Lewis bases – tend to coordinate to the metal

• Dacquet, 1997 An unavoidable challenge for aromatic ring hydrogenations is controlling the stereochemistry of the product during the hydrogenation reduction process. In 1997, Dacquet and co-workers conducted a hydrogenation reduction of the natural product (−)-tabersonine using platinum dioxide as a

Advances in Zr-mediated radical transformations and applications to total synthesis

• Hiroshige Ogawa and
• Hugh Nakamura

Beilstein J. Org. Chem. 2026, 22, 71–87, doi:10.3762/bjoc.22.3

• from silicate minerals (ZrSiO4) in igneous rocks, which are widely distributed in the Earth's crust. Consequently, compared with certain rare metals whose sources are limited – such as iridium, rhodium, palladium, platinum, and ruthenium – zirconium is relatively inexpensive and readily available

Sustainable electrochemical synthesis of aliphatic nitro-NNO-azoxy compounds employing ammonium dinitramide and their in vitro evaluation as potential nitric oxide donors and fungicides

• Alexander S. Budnikov,
• Nikita E. Leonov,
• Michael S. Klenov,
• Andrey A. Kulikov,
• Igor B. Krylov,
• Timofey A. Kudryashev,
• Aleksandr M. Churakov,
• Alexander O. Terent’ev and
• Vladimir A. Tartakovsky

Beilstein J. Org. Chem. 2025, 21, 2739–2754, doi:10.3762/bjoc.21.211

• Table 1. After extensive optimization, we found that a 77% yield (75% isolated yield) of 2a was achieved by performing the model reaction under CCE (constant current electrolysis) conditions in an undivided electrochemical cell, using a platinum plate as the anode and a platinum wire as the cathode

• , with 4 equiv of ADN as both the reagent and the supporting electrolyte (Table 1, entry 1). Entries 2 and 3 show that the best results were obtained with a platinum plate anode and a platinum wire cathode. The evaluation of the charge passed revealed that the optimal amount was 2 F per mole 1a (Table 1

• -nitrosopropane (1a) (experimental details for Table 1): In a manner analogous to one described in [87], an undivided 10 mL electrochemical cell was equipped with a platinum plate, stainless steel, nickel, graphite, carbon felt, or glassy carbon plate anode (40 × 10 mm) and a platinum plate, platinum wire (d = 1

Synthesis of new tetra- and pentacyclic, methylenedioxy- and ethylenedioxy-substituted derivatives of the dibenzo[c,f][1,2]thiazepine ring system

• Gábor Berecz,
• András Dancsó,
• Mária Tóthné Lauritz,
• Loránd Kiss,
• Gyula Simig and
• Balázs Volk

Beilstein J. Org. Chem. 2025, 21, 2645–2656, doi:10.3762/bjoc.21.205

• 100 μL platinum pan in 25 mL/min nitrogen atmosphere. Melting properties of the amorphous samples (21b, 38d, 54f) were also studied by a TA Instruments Discovery DSC differential scanning calorimeter in the 25–120 °C temperature range with a 10 °C/min heating rate using 2.5 to 3.0 mg sample in a

Pathway economy in cyclization of 1,n-enynes

• Hezhen Han,
• Wenjie Mao,
• Bin Lin,
• Maosheng Cheng,
• Lu Yang and
• Yongxiang Liu

Beilstein J. Org. Chem. 2025, 21, 2260–2282, doi:10.3762/bjoc.21.173

• carbazole 113 (Scheme 23, path a). In contrast, the utilization of PtCl4 as a catalyst induced a distinct reaction pathway involving a platinum carbene intermediate 114. This intermediate underwent a different 1,2-alkyl shift, leading to the selective formation of carbazole derivative 115 (Scheme 23, path b

Electrochemical cyclization of alkynes to construct five-membered nitrogen-heterocyclic rings

• Lifen Peng,
• Ting Wang,
• Zhiwen Yuan,
• Bin Li,
• Zilong Tang,
• Xirong Liu,
• Hui Li,
• Guofang Jiang,
• Chunling Zeng,
• Henry N. C. Wong and
• Xiao-Shui Peng

Beilstein J. Org. Chem. 2025, 21, 2173–2201, doi:10.3762/bjoc.21.166

• sustainable strategy for the preparation of 3-selenylindoles. In 2023, Satyanarayana also described a similar electrochemical cascade approach towards 3-selenylindoles from 2-alkynylanilines (Scheme 6) [202]. When graphite was used as anode, platinum as cathode and LiClO4 as electrolyte, the electrochemical

• obtained by electrochemical reductive cascade annulation of o-alkynylbenzamide (Scheme 10) [212]. Under 10 mA constant current with two platinum plate as electrodes and n-Bu4NPF6 as electrolyte, the reductive cascade cyclization of o-alkynylbenzamide 27 proceeded smoothly in the presence of N,N

• indolizine (Scheme 11) [218]. Under electrolysis (two platinum plate as electrodes, NH4I as electrolyte and electrocatalyst, 5 mA, 8.4 F/mol), the aminooxygenation of alkyne 29 underwent efficiently to form the desired indolizine 30 in good to excellent yield. The reaction was compatible with many groups

C2 to C6 biobased carbonyl platforms for fine chemistry

• Jingjing Jiang,
• Muhammad Noman Haider Tariq,
• Florence Popowycz,
• Yanlong Gu and
• Yves Queneau

Beilstein J. Org. Chem. 2025, 21, 2103–2172, doi:10.3762/bjoc.21.165

Synthesis, biological and electrochemical evaluation of glycidyl esters of phosphorus acids as potential anticancer drugs

• Almaz A. Zagidullin,
• Emil R. Bulatov,
• Mikhail N. Khrizanforov,
• Damir R. Davletshin,
• Elvina M. Gilyazova,
• Ivan A. Strelkov and
• Vasily A. Miluykov

Beilstein J. Org. Chem. 2025, 21, 1909–1916, doi:10.3762/bjoc.21.148

• (0.01 M KCl) was used as a reference electrode. A platinum wire was used as an auxiliary electrode. The scanning rate was 100 mV s−1. Measurements were carried out in a thermostatted electrochemical cell (volume 5 mL) in an inert gas atmosphere (N2). Between measurements or before recording the

Stereoselective electrochemical intramolecular imino-pinacol reaction: a straightforward entry to enantiopure piperazines

• Margherita Gazzotti,
• Fabrizio Medici,
• Valerio Chiroli,
• Laura Raimondi,
• Sergio Rossi and
• Maurizio Benaglia

Beilstein J. Org. Chem. 2025, 21, 1897–1908, doi:10.3762/bjoc.21.147

• moderate yields and required geometrically complex divided cells. In 1989, a more efficient procedure was introduced by Torii et al. [43], who simplified the process by using PbBr2, TFA and THF, in a beaker-type undivided cell equipped with two platinum electrodes. This approach afforded vicinal diamines

• volume) equipped with two electrodes under galvanostatic conditions (constant current 5 mA, 2.5 mA/cm2) and the results are summarized in Table 1. Using platinum electrodes and NEt₄BF₄ as electrolyte, the tetrasubstituted piperazine 2a was obtained as a single stereoisomer in 51% yield in CH3CN, which

• increased to 68% when DMF was used (Table 1, entry 2). The replacement of the platinum anode with graphite or zinc (Table 1, entries 4 and 5) had no significant effect on the yield. Similarly, increasing the total charge from 2.2 to 2.5 F/mol (Table 1, entries 6 and 7) resulted in only marginal changes

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

• process occurs in a concerted manner through the corresponding five-membered transition state, the germanium and magnesium cyaphide complexes are significantly more reactive (i.e., leading to a lower-barrier process, ΔG≠ ≈ 20 kcal/mol) than their platinum or gold counterparts, which exhibit barriers

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

• ring expansion for 2,2’-di(arylethynyl)biphenyls 53a–f [54]. The platinum-catalysed reaction led to a series of azulenophenanthrens 54a–f in yields ranging from 40% to 80%. A similar strategy was employed very recently in the synthesis of azulene-embedded isomers of linear acenes (Scheme 9) by Zhang

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

• in a THF/MeOH solvent mixture, using a constant current electrolysis setup with a reticulated vitreous carbon (RVC) anode and a platinum cathode. The substrate scope was extensively investigated, and a broad array of N-aryl substituents was well tolerated, including electron-donating motifs such as

• employed as a redox catalyst, Na2CO3 as a base, and n-Bu4NBF4 as the electrolyte, all participating in an undivided electrolytic cell with a reticulated vitreous carbon (RVC) anode and a platinum (Pt) cathode at a constant current of 10 mA, in a co-solvent mixture of MeOH/THF 2:1 for 3 hours to deliver the

• carbocyclization with diethyl malonate, yielding fluorinated pyrroloquinazolinones in acceptable to high yields [11]. The reaction was conducted in an undivided cell with a carbon cloth anode and a platinum (Pt) cathode, using K2CO3 (10 mol %) as the base, Ir(ppy)3 (3 mol %) as the photocatalyst, and an equivalent

Gold extraction at the molecular level using α- and β-cyclodextrins

• Susana Santos Braga

Beilstein J. Org. Chem. 2025, 21, 1116–1125, doi:10.3762/bjoc.21.89

• -OES, the precipitation ability of α-CD (0.2 mmol × 2) of a solution containing gold in the presence of palladium and platinum (33 mM KAuBr4, 33 mM K2PdBr4, and saturated K2PtBr4, at ≈26 mM), with 78.3% of the gold precipitating out of solution while for the other metals there was only precipitation of

• precious metals [42]. The process of gold precipitation with cyclodextrins, bromic acid and potassium hydroxide to form the potassium bromoaurate salt was patented, with patent coverage expanding to metals like silver, platinum, palladium, and rare earths, as well as the use of other cyclodextrins, β- and

Recent total synthesis of natural products leveraging a strategy of enamide cyclization

• Chun-Yu Mi,
• Jia-Yuan Zhai and
• Xiao-Ming Zhang

Beilstein J. Org. Chem. 2025, 21, 999–1009, doi:10.3762/bjoc.21.81

• the α-position of enamide to be an active cyclization site, with the alkyne tether acting as the nucleophile. Since it is well-established that alkynes, when activated by transition metals such as gold or platinum, can also function as electrophiles, modulating the reactivity of the decahydroquinoline

Recent advances in the electrochemical synthesis of organophosphorus compounds

• Babak Kaboudin,
• Milad Behroozi,
• Sepideh Sadighi and
• Fatemeh Asgharzadeh

Beilstein J. Org. Chem. 2025, 21, 770–797, doi:10.3762/bjoc.21.61

• synthesis of various organophosphorus compounds through the formation of phosphorus–carbon, phosphorus–nitrogen, phosphorus–oxygen, phosphorus–sulfur, and phosphorus–selenium bonds. The impact of different electrodes is also discussed in this matter. Graphite, platinum, RVC, and nickel electrodes have been

• , phosphorus–sulfur, and phosphorus–selenium bonds. The impact of different electrodes is also discussed in this matter. Graphite, platinum, reticulated vitreous carbon (RVC), and nickel electrodes have been used extensively for the electrochemical synthesis of organophosphorus compounds. Review

• electrode with the reaction solution. The oxidation–reduction process complements each other, and the surface of the electrode in the reaction is critical. The material of the electrode is essential [44]. Various electrodes, including carbon (C), platinum (Pt), nickel (Ni), and reticulated vitreous carbon

Entry to 2-aminoprolines via electrochemical decarboxylative amidation of N‑acetylamino malonic acid monoesters

• Olesja Koleda,
• Janis Sadauskis,
• Darja Antonenko,
• Edvards Janis Treijs,
• Raivis Davis Steberis and
• Edgars Suna

Beilstein J. Org. Chem. 2025, 21, 630–638, doi:10.3762/bjoc.21.50

• undesired cathodic reduction. Indeed, trace amounts of 2-aminoproline derivative 6g (<4%) could be obtained by replacing SS as the cathode material with platinum that has a low overpotential for hydrogen evolution reaction [14]. To avoid the undesired cathodic reduction of the nitro group, the electrolysis

• column chromatography. Cyclic voltammetry studies CV experiments were carried out in an SVC-2 (ALS, Japan) three-electrode cell using a PalmSens4 (PalmSens). A glassy carbon disk (diameter: 1.6 mm) served as the working electrode and a platinum wire as the counter electrode. The glassy carbon disk was

Red light excitation: illuminating photocatalysis in a new spectrum

• Lucas Fortier,
• Corentin Lefebvre and
• Norbert Hoffmann

Beilstein J. Org. Chem. 2025, 21, 296–326, doi:10.3762/bjoc.21.22

• , which exploits the properties of red-light excitation while addressing the energy constraints posed by low-energy photons. Whereas multiple works addressing the upconversion phenomenon involving heavy metals like palladium, platinum [23][24] or osmium [25], grafted ruthenium complexes over ytterbium and

Synthesis, structure and π-expansion of tris(4,5-dehydro-2,3:6,7-dibenzotropone)

• Yongming Xiong,
• Xue Lin Ma,
• Shilong Su and
• Qian Miao

Beilstein J. Org. Chem. 2025, 21, 1–7, doi:10.3762/bjoc.21.1

• graphite [22]. It was earlier prepared in Ar matrices [23] or via demetallation of a platinum complex of 4,5-dehydro-2,3:6,7-dibenzotropone [1]. More recently, compound 1 was prepared via Pd-catalyzed cyclotrimerization of 4-bromo-2,3:6,7-dibenzotropone (4 in Scheme 1) [22]. Herein we report an alternative

Synthesis of benzo[f]quinazoline-1,3(2H,4H)-diones

• Ruben Manuel Figueira de Abreu,
• Peter Ehlers and
• Peter Langer

Beilstein J. Org. Chem. 2024, 20, 2708–2719, doi:10.3762/bjoc.20.228

• attempt, we used platinum(II) chloride (PtCl2) as the Lewis acid and 4a as the model starting material. The reaction afforded a mixture of the desired product 5a and the starting material. Separation of both compounds proved to be difficult and, hence, optimisation was carried out as depicted in Table 1

Applications of microscopy and small angle scattering techniques for the characterisation of supramolecular gels

• Connor R. M. MacDonald and
• Emily R. Draper

Beilstein J. Org. Chem. 2024, 20, 2608–2634, doi:10.3762/bjoc.20.220

• number of structural features, but the sample preparation required can lead to significant changes in the materials morphology. EM requires many preparative steps to allow structures to be imaged including the application of an ultrathin coating of carbon, gold, or platinum. These are applied to conduct

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

• . However, it should be noted that anodic oxidations often require electrodes with high resistance to oxidation, such as platinum electrodes, or inert electrodes with a highly developed surface, like reticulated vitreous carbon (RVC). Anodic oxidations generally involve the evolution of hydrogen (indicated

• methanol, equipped with a graphite anode and a platinum plate cathode, under a current of 10 mA at 60 °C for 3–20 hours. Several electrochemical LSF of pharmacologically active molecules were tested, including naproxen methyl ester, a derivative of aminoglutethimide, and paracetamol. The corresponding

• electrolyte, and carbon felt and platinum plate as electrodes, the intramolecular hydroamination proceeded smoothly, yielding azetidines in moderate to good yields. This method was applied to the LSF of celecoxib, zonisamide, and dansyl amide (Scheme 33a). Additionally, the allylation of aldehydes also

Harnessing the versatility of hydrazones through electrosynthetic oxidative transformations

• Aurélie Claraz

Beilstein J. Org. Chem. 2024, 20, 1988–2004, doi:10.3762/bjoc.20.175

• -derived NH-acylhydrazones to build 1,3,4-oxadiazole derivatives in good yields. The electrolysis was conducted under galvanostatic conditions in methanol using a carbon graphite anode and a platinum cathode. From a mechanistic point of view, in situ condensation of acylhydrazines 28 with α-keto acids 27

• electrolyte with potassium carbonate as a base and two platinum electrodes. Mechanistically, condensation of the two reactants formed isatin-derived acylhydrazone 37. Hydrolysis of the latter in the presence of the inorganic base gave rise to potassium carboxylate 39. Meanwhile, two consecutive SET oxidations

• -tetraethylammonium perchlorate solution under constant potential in a divided cell equipped with platinum gauze anode and nickel cathode. Such a transformation constituted a straightforward route to the corresponding fused s-triazolo perchlorates 46 in moderate to high yield. Coulometric analysis established that

Electrochemical radical cation aza-Wacker cyclizations

• Sota Adachi and
• Yohei Okada

Beilstein J. Org. Chem. 2024, 20, 1900–1905, doi:10.3762/bjoc.20.165

• ), with platinum (Pt) as a cathode. To our delight, a constant-current condition at 1 mA was productive, and the desired five-membered pyrrolidine 2 was obtained in high yield (Table 1, entry 2). During the screening of conditions, the addition of acetonitrile (CH3CN) was found to be effective, probably

Synthesis of polycyclic aromatic quinones by continuous flow electrochemical oxidation: anodic methoxylation of polycyclic aromatic phenols (PAPs)

• Hiwot M. Tiruye,
• Solon Economopoulos and
• Kåre B. Jørgensen

Beilstein J. Org. Chem. 2024, 20, 1746–1757, doi:10.3762/bjoc.20.153

• short distance between the electrodes, and easily reproduceable conditions. The electrochemical oxidation of phenols has been performed with platinum anodes [37][41], and carbon/platinum worked well for the oxidation of toluene dissolved in methanol with tetraethylammonium tosylate (Et4NOTs) as a

• the four-electron oxidation product 1,1-dimethoxynaphthalen-2(1H)-one (2). Best results were obtained with a carbon/platinum electrode pair, although stainless steel (SS) could also be used as cathode. The experiments were conducted with a 3:1 mixture of methanol/tetrahydrofuran (optimization not

• cell equipped with a platinum-coated cathode and a carbon-filled PPS (polyphenylene sulfide) micro-channel anode separated by a polyetheretherketone (PEEK) gasket [40]. Further experimental details and characterization of new compounds are given in Supporting Information File 1. General procedure A