Photocatalyzed elaboration of antibody-based bioconjugates

• Marine Le Stum,
• Eugénie Romero and
• Gary A. Molander

Beilstein J. Org. Chem. 2025, 21, 616–629, doi:10.3762/bjoc.21.49

• disulfide bridges. More recently, Lang et al. developed an approach using dual photoredox/nickel-catalyzed antibody functionalization [45], demonstrating the selective modification of Cys residues through photocatalytic methods (Figure 7). A key advantage of this strategy lies in the use of readily

• nickel catalysis for the functionalization of antibodies in a very elegant and practical manner, the method has been applied to Cys, which necessitates the use of a reductant to access the free form of Cys. Another consequence was the high and non-reproducible DAR. The development of such methods applied

• procedure developed by Bräse et al. on photoinduced disulfide rebridging method. Schematic procedure developed by Lang et al. on a photoinduced dual nickel photoredox-catalyzed approach. The antibody shown in this figure is from https://www.gettyimages.de/detail/illustration/monoclonal-antibody-igg2a

Formaldehyde surrogates in multicomponent reactions

• Cecilia I. Attorresi,
• Javier A. Ramírez and
• Bernhard Westermann

Beilstein J. Org. Chem. 2025, 21, 564–595, doi:10.3762/bjoc.21.45

• , 5 mol %) [63], indium (as In2O3 nanoparticles, 5 mol %) [64], iron (as FeCl3, 20 mol %) [65], cobalt (as CoBr2, 10 mol %) [66], and nickel (as Ni(py)4Cl2, 15 mol %) [67] can act as metal catalyst for the 3CC reaction. In all these cases, the temperature was lower (usually between 60–80 °C) compared

• addition) more temperature dependent. However, in the case of nickel catalysis, during AHA coupling, a suitable ligand, such as bipyridine, is needed for the in situ formation of a metal complex that activates the C–H and C–X bond [67]. The solvents used most in the AHA coupling are CH3CN [62][65][66][67

Organocatalytic kinetic resolution of 1,5-dicarbonyl compounds through a retro-Michael reaction

• James Guevara-Pulido,
• Fernando González-Pérez,
• José M. Andrés and
• Rafael Pedrosa

Beilstein J. Org. Chem. 2025, 21, 473–482, doi:10.3762/bjoc.21.34

• of 18 with Raney nickel in ethanol at room temperature gave a 3:1 mixture of anti/syn-19. The absolute configuration of anti-19 is (2R,3S), indicating that in the resolution process, the major enantiomer corresponds to the anti-(3S,4R)-5-oxo-3,4,5-triphenylpentanal. Having established that the major

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

• [Os(tpy)2]2+/red-light irradiation system well-suited for large-scale manufacturing. In this way, the authors have also tested different osmium complexes in various well-established photocatalyzed reactions such as copper, palladium, cobalt, and nickel metallophotoredox couplings using red light

• , thereupon highlighting potential for broad applications in photoredox catalysis on an industrial scale. In this context, T. Rovis et al. have studied a C–N cross-coupling Buchwald–Hartwig-like reaction using dual nickel and osmium catalysis under red-light activation, addressing common challenges such as

• ). The mechanism of the reaction presented by the authors involves two different catalytic cycles as presented in Scheme 3c. After excitation of the osmium complex 13, this latter is reduced via the use of a tertiary amine to give the active species 14 able to oxidize the formed nickel complex 15 in the

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

• , yielding an α-aryloxylation product 37. After their investigation of Cu-catalyzed electrochemical reactions, the same group further developed synergistic Cu/Ni catalysis for the stereodivergent electrooxidation of benzoxazolyl acetate (Figure 10) [59]. In this catalytic system, copper and nickel activate

• identical racemic carbonyl nucleophiles to generate Cu-enolate 44 and Ni-enolate 43 simultaneously (Figure 10). The Ni-enolate 43 undergoes anodic oxidation through single-electron transfer, releasing nickel-bound α-carbonyl radical 45, whereas the copper complex 44 remains electrochemically inert under

Nickel-catalyzed cross-coupling of 2-fluorobenzofurans with arylboronic acids via aromatic C–F bond activation

• Takeshi Fujita,
• Haruna Yabuki,
• Ryutaro Morioka,
• Kohei Fuchibe and
• Junji Ichikawa

Beilstein J. Org. Chem. 2025, 21, 146–154, doi:10.3762/bjoc.21.8

• , Ibaraki 305-8571, Japan Sagami Chemical Research Institute, 2743-1 Hayakawa, Ayase, Kanagawa 252-1193, Japan 10.3762/bjoc.21.8 Abstract 2-Fluorobenzofurans underwent efficient nickel-catalyzed coupling with arylboronic acids through the activation of aromatic C–F bonds. This method allowed us to

• successfully synthesize a range of 2-arylbenzofurans with various substituents. The reaction, which proceeded under mild conditions, involved β-fluorine elimination from nickelacyclopropanes formed by the interaction of 2-fluorobenzofurans with zero-valent nickel species. This protocol facilitates orthogonal

• coupling reactions of aromatic C–F and C–Br bonds with arylboronic acids. Keywords: arylboronic acid; benzofuran; C–F bond activation; cross-coupling; nickel; Introduction The metal-catalyzed activation of aromatic carbon–fluorine (C–F) bonds is widely recognized as a challenging task in synthetic

Facile one-pot reduction of β-nitrostyrenes to phenethylamines using sodium borohydride and copper(II) chloride

• Laura D’Andrea and
• Simon Jademyr

Beilstein J. Org. Chem. 2025, 21, 39–46, doi:10.3762/bjoc.21.4

• ), and appetite suppressants (e.g., phentermine) [6]. Phenethylamines can be produced via numerous different procedures [7]. One of the oldest methods involves the reduction of benzyl cyanide with H2 in liquid ammonia with Raney-Nickel catalyst at 130 °C, and high pressure [8]. Another known method is

Synthesis of fluorinated acid-functionalized, electron-rich nickel porphyrins

• Mike Brockmann,
• Jonas Lobbel,
• Lara Unterriker and
• Rainer Herges

Beilstein J. Org. Chem. 2024, 20, 2954–2958, doi:10.3762/bjoc.20.248

• –CH2–(CF2)n–COOCH3) with triflate as leaving group in terminal position are easily accessible and versatile building blocks for attaching long chain acids (pKa 0–1) to substrates in Williamson ether-type reactions. Keywords: acid-functionalized porphyrin; electron-rich porphyrin; nickel porphyrin

• Williamson ether synthesis to yield 22 (78%), 23 (44%), and 24 (44%). Compounds 22, 23, and 24 were used as aldehyde components in the Rothemund-type synthesis of metal-free porphyrins 26 (9%), 27 (18%), and 28 (21%) (see Scheme 3). Metalation was achieved with nickel acetylacetonate to obtain the ester

Synthesis of fluoroalkenes and fluoroenynes via cross-coupling reactions using novel multihalogenated vinyl ethers

• Yukiko Karuo,
• Keita Hirata,
• Atsushi Tarui,
• Kazuyuki Sato,
• Kentaro Kawai and
• Masaaki Omote

Beilstein J. Org. Chem. 2024, 20, 2691–2703, doi:10.3762/bjoc.20.226

• reagents have been developed. These reagents are easily being converted into multisubstituted fluoroalkenes through cross-coupling using palladium, nickel, copper, ruthenium, and manganese catalysts [26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41]. Hosoya and Niwa et al. published the

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

• complex compounds (Scheme 35). In addition, Niu and coworkers reported a similar work on a cobalt-electrocatalyzed atroposelective C–H annulation of benzamides with acetylenes [48]. 1.3.3 Ni-assisted anodic oxidation: Apart from cobalt, nickel complexes have also been applied in anionic oxidations and

• late-stage functionalizations. In 2020, Ackermann and coworkers reported the challenging C–H alkoxylation of (hetero)arenes with sterically encumbered secondary alcohols via a nickel electrocatalyzed protocol [49]. A traceless removable quinoline amide in the meta position was employed as a directing

• group. Based on extensive mechanistic studies, they proposed the formation of a formal Ni(IV) complex during the process. Remarkably, nickel proved to be uniquely effective for this protocol, as other transition-metal catalysts based on Cu, Co, Pd, Ir, Ru, and Rh did not catalyze the reaction (Scheme 36

Natural resorcylic lactones derived from alternariol

• Joachim Podlech

Beilstein J. Org. Chem. 2024, 20, 2171–2207, doi:10.3762/bjoc.20.187

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

• -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

• electromediator for synthesising α-diazoketones 139 in good yields. The electrolysis was performed at low temperature in a divided cell equipped with a platinum anode and a nickel cathode. It was not possible to isolate the diazo compounds arising from the electrooxidation of 4,4’-dimethylbenzilhydrazone and 4,4

• unsubstituted hydrazones 140. After intensive parameter optimizations, good yields were achieved under galvanostatic conditions in a simple divided cell equipped with cheap carbon graphite anode and nickel cathode using potassium iodide and ammonium acetate as electrolyte. Cyclic voltammetry analysis suggested

Radical reactivity of antiaromatic Ni(II) norcorroles with azo radical initiators

• Siham Asyiqin Shafie,
• Ryo Nozawa,
• Hideaki Takano and
• Hiroshi Shinokubo

Beilstein J. Org. Chem. 2024, 20, 1967–1972, doi:10.3762/bjoc.20.172

• . Finally, another isobutyronitrile radical reacts with I at the convex face to form the major product 2a, with two alkyl substituents on the same side of the molecule. The mean-plane deviation (MPD) of I was 0.293 Å, where the mean plane was defined by carbon, nitrogen, and nickel atoms of the norcorrole

Discovery of antimicrobial peptides clostrisin and cellulosin from Clostridium: insights into their structures, co-localized biosynthetic gene clusters, and antibiotic activity

• Moisés Alejandro Alejo Hernandez,
• Katia Pamela Villavicencio Sánchez,
• Rosendo Sánchez Morales,
• Karla Georgina Hernández-Magro Gil,
• David Silverio Moreno-Gutiérrez,
• Eddie Guillermo Sanchez-Rueda,
• Yanet Teresa-Cruz,
• Brian Choi,
• Armando Hernández Garcia,
• Alba Romero-Rodríguez,
• Oscar Juárez,
• Siseth Martínez-Caballero,
• Mario Figueroa and
• Corina-Diana Ceapă

Beilstein J. Org. Chem. 2024, 20, 1800–1816, doi:10.3762/bjoc.20.159

• purifications using affinity chromatography with a 1 mL His Trap nickel affinity column. Sonication lysis was performed and centrifuged during 30 min, at 8,000 rpm, 4 °C. The supernatants were loaded into the column. The column was washed with 5 column volumes of LanA wash buffer 1 (20 mM Tris pH 7.5, 500 mM

New triazinephosphonate dopants for Nafion proton exchange membranes (PEM)

• Fátima C. Teixeira,
• António P. S. Teixeira and
• C. M. Rangel

Beilstein J. Org. Chem. 2024, 20, 1623–1634, doi:10.3762/bjoc.20.145

• commercially available and were prepared from 4-hydroxyphenyl- or 4-aminophenyl-based derivatives. The first nucleophile to be synthesized was diethyl (4-hydroxyphenyl)phosphonate (2) [51], starting from 4-bromophenol (3) and triethyl phosphite. When this reaction was carried out in the presence of nickel(II

• ] was also prepared, using the same reaction conditions, by the reaction between 1-bromo-4-nitrobenzene (5) and diethyl phosphonate, in the presence of Pd(PPh3)4 as catalyst and triethylamine, since the use of triethyl phosphite in the presence on nickel(II) bromide do not allow the formation of the

Synthetic applications of the Cannizzaro reaction

• Bhaskar Chatterjee,
• Dhananjoy Mondal and
• Smritilekha Bera

Beilstein J. Org. Chem. 2024, 20, 1376–1395, doi:10.3762/bjoc.20.120

• nickel(II) complex 96 to the same basic conditions resulted in the formation of the Cannizzaro adduct hemiacetal Ni(II) complex 97 in 56–65% yield predominantly with the byproduct 98 in less than 5% yield (Scheme 26) [93]. Schmalz and coworkers transformed 2-formylarylketones 99 into 3-substituted

Generation of alkyl and acyl radicals by visible-light photoredox catalysis: direct activation of C–O bonds in organic transformations

• Mithu Roy,
• Bitan Sardar,
• Itu Mallick and
• Dipankar Srimani

Beilstein J. Org. Chem. 2024, 20, 1348–1375, doi:10.3762/bjoc.20.119

• using tertiary alkyl oxalates and aryl bromides (Scheme 10). This is achieved through the synergistic combination of photoredox and nickel catalysis. This approach facilitates the formation of diverse trisubstituted olefins with outstanding regioselectivity and syn-stereoselectivity. The proposed

• xanthate esters with aryl bromides via dual photoredox and nickel catalysis (Scheme 14). sec-BuBF3K was found to be the best radical precursor for generating the alkyl radicals that initiated the C–O bond cleavage of O-benzyl xanthate esters to provide benzyl radicals. Next, the benzyl radicals underwent

• nickel-catalyzed cross-coupling reactions with aryl halides to deliver the desired cross-coupled products. Interestingly, in absence of any xanthate, sec-butyl radicals underwent cross-coupling reactions with aryl halides to form sec-butyl arenes, whereas in the presence of xanthate, no undesired sec

Rhodium-catalyzed homo-coupling reaction of aryl Grignard reagents and its application for the synthesis of an integrin inhibitor

• Kazuyuki Sato,
• Satoki Teranishi,
• Atsushi Sakaue,
• Yukiko Karuo,
• Atsushi Tarui,
• Kentaro Kawai,
• Hiroyuki Takeda,
• Tatsuo Kinashi and
• Masaaki Omote

Beilstein J. Org. Chem. 2024, 20, 1341–1347, doi:10.3762/bjoc.20.118

• . Therefore, alternative procedures for homo-coupling reactions using other transition-metal catalysts such as palladium, nickel, manganese, and iron have been developed [5][6][7][8][9][10][11][12][13]. In recent years, transition-metal-free coupling reactions have also been developed for environmentally

Carbonylative synthesis and functionalization of indoles

• Alex De Salvo,
• Raffaella Mancuso and
• Xiao-Feng Wu

Beilstein J. Org. Chem. 2024, 20, 973–1000, doi:10.3762/bjoc.20.87

• time, Wu and co-workers contributed to the introduction of two new syntheses of N-aroylindole derivatives by means of nickel catalysis. In 2021, they reported a nickel-catalyzed carbonylative cyclization of 2-nitroalkynes and aryl iodides with Co2(CO)8 as the CO source. The reaction was performed in

• the presence of Ni(dme)Cl2 (a nickel(II) chloride ethylene glycol dimethyl ether complex), dtbbpy (4,4-di-tert-butyl-2,2-dipyridyl), Zn(0) and ZnI2 in DMF at 120 °C [42] (Scheme 22). The nickel catalyst catalyzed the oxidative addition and CO insertion on aryl iodide compounds, while the Zn/ZnI2

(Bio)isosteres of ortho- and meta-substituted benzenes

• H. Erik Diepers and
• Johannes C. L. Walker

Beilstein J. Org. Chem. 2024, 20, 859–890, doi:10.3762/bjoc.20.78

• esterification of alcohol (±)-5 gave redox active ester (±)-6, which was itself shown to be a suitable substrate for nickel-catalysed decarboxylative cross coupling reactions to aryl-substituted BCPs (±)-7. Oxidation of alcohol (±)-8 gave acid (±)-9 which yielded amine (±)-10 after a Curtius rearrangement

• conditions in the transformation of alcohol 153 to aldehyde 154. All of these transformations could be performed without reduction in diastereomeric ratio. Additionally, the authors showed that acid 152 can undergo nickel-catalysed decarboxylative cross coupling reactions via redox active ester 156 to afford

A myo-inositol dehydrogenase involved in aminocyclitol biosynthesis of hygromycin A

• Michael O. Akintubosun and
• Melanie A. Higgins

Beilstein J. Org. Chem. 2024, 20, 589–596, doi:10.3762/bjoc.20.51

• /off cycles for 5 min at a duty cycle of 50). Initial purification was performed with gravity filtration using nickel-nitrilotriacetic acid (Ni-NTA) resin (GE Healthcare). Cell lysate was loaded onto the Ni-NTA resin and washed with binding buffer. Protein was eluted using increasing concentrations of

Switchable molecular tweezers: design and applications

• Pablo Msellem,
• Maksym Dekthiarenko,
• Nihal Hadj Seyd and
• Guillaume Vives

Beilstein J. Org. Chem. 2024, 20, 504–539, doi:10.3762/bjoc.20.45

Mechanisms for radical reactions initiating from N-hydroxyphthalimide esters

• Carlos R. Azpilcueta-Nicolas and
• Jean-Philip Lumb

Beilstein J. Org. Chem. 2024, 20, 346–378, doi:10.3762/bjoc.20.35

• decarboxylative cross-coupling (DCC) of NHPI esters with organometallic reagents, resembling classic Kumada, Negishi, and Suzuki couplings, has been enabled by nickel (Ni), cobalt (Co), iron (Fe), and copper (Cu) catalysts [84][85][86][87][88][89][90][91] (Scheme 23A). The typical mechanism begins by

Copper-promoted C5-selective bromination of 8-aminoquinoline amides with alkyl bromides

• Changdong Shao,
• Chen Ma,
• Li Li,
• Jingyi Liu,
• Yanan Shen,
• Chen Chen,
• Qionglin Yang,
• Tianyi Xu,
• Zhengsong Hu,
• Yuhe Kan and
• Tingting Zhang

Beilstein J. Org. Chem. 2024, 20, 155–161, doi:10.3762/bjoc.20.14

• ·H2O (Table 1, entries 2–9). To our delight, copper salts were effective, giving the desired product 3aa in excellent yields of 88–95% (Table 1, entries 7–9). Cuprous salts, cobalt chloride, and nickel acetate were partially efficient for the reaction, providing product 3aa in 85% yield (Table 1

A novel recyclable organocatalyst for the gram-scale enantioselective synthesis of (S)-baclofen

• Gyula Dargó,
• Dóra Erdélyi,
• Balázs Molnár,
• Péter Kisszékelyi,
• Zsófia Garádi and
• József Kupai

Beilstein J. Org. Chem. 2023, 19, 1811–1824, doi:10.3762/bjoc.19.133

• be synthesized in two steps. The nitro acid (S)-18 was obtained using HCl in THF in good yield (70%), which could be reduced to (S)-baclofen hydrochloride using Raney nickel as catalyst (Scheme 4) [38]. Conclusion In conclusion, we have prepared a new lipophilic cinchona squaramide organocatalyst 2