Visible-light-driven NHC and organophotoredox dual catalysis for the synthesis of carbonyl compounds

• Vasudevan Dhayalan

Beilstein J. Org. Chem. 2025, 21, 2584–2603, doi:10.3762/bjoc.21.200

• carbenes (NHCs) with photocatalysts. The review encompasses transition-metal-based photocatalytic reactions for C–C and C–HA cross-coupling reactions involving various acyl fluorides, amides, aldehydes, carboxylic acids, and esters, highlighting their broad applications in organic synthesis and medicinal

• -photocatalyst, leading to various β-aryl keto ester derivatives 20 in good to excellent yields. The key steps of the reactions undergo radical–radical cross-coupling with the alkyl ester radical E and benzyl radical B to afford the desired keto-esters 20 in up to 88% yield. This catalytic process displayed good

• V vs SCE in CH3CN). The resulting oxidized Rh6G•+, with a ground-state oxidation potential of Eox = +1.23 V vs SCE in CH3CN. This catalysis enables an efficient and straightforward photocatalytic preparation of functionalized aryl esters 25 through a radical pathway (Scheme 10) [60]. The NHC

Assembly strategy for thieno[3,2-b]thiophenes via a disulfide intermediate derived from 3-nitrothiophene-2,5-dicarboxylate

• Roman A. Irgashev

Beilstein J. Org. Chem. 2025, 21, 2489–2497, doi:10.3762/bjoc.21.191

• , but it was obtained as a mixture of ester forms, namely dimethyl and diethyl esters in ethanol, and dimethyl and diisopropyl esters in isopropanol. These results indicate that the reaction with alcohol solvents resulted in partial transesterification of the methoxycarbonyl groups, while reductive

Transformation of the cyclohexane ring to the cyclopentane fragment of biologically active compounds

• Natalya Akhmetdinova,
• Ilgiz Biktagirov and
• Liliya Kh. Faizullina

Beilstein J. Org. Chem. 2025, 21, 2416–2446, doi:10.3762/bjoc.21.185

• 6,5,6-abeoabietane scaffold and impressive antitumor activity. α-Diazoketone 124 was synthesized from commercially available 1,2,4-trimethoxybenzene (123) [64] by a series of synthetic transformations, and converted by Wolff rearrangement to esters 125 and 126 with a trans-fused 6,5,6-ring system

• product of cyclohexane ring opening (Scheme 26). A decrease in the methanol content of the mixture to 0.5% was accompanied by a slowdown in the process and the appearance of keto enol 149 in solution. Replacing methanol with isopropanol under these conditions resulted in the formation of isopropyl esters

• Dotson et al. [84] for cis/trans salts 159 (Scheme 30). The authors noted that photochemical experiments carried out in benzene solutions with benzylic esters cis-159 or trans-159 gave complex product mixtures. To achieve higher conversion, a photochemical reaction was carried out in the crystalline

The high potential of methyl laurate as a recyclable competitor to conventional toxic solvents in [3 + 2] cycloaddition reactions

• Ayhan Yıldırım and
• Mustafa Göker

Beilstein J. Org. Chem. 2025, 21, 2389–2415, doi:10.3762/bjoc.21.184

• skin of human subjects were detected. However, evidence of ocular irritation at very low levels was obtained. Furthermore, it has been determined that 100–69% of methyl laurate is readily biodegraded aerobically following a 30-day period. The utilization of certain fatty acid methyl esters, including

• characteristics, arising from the ester group and the non-polar hydrocarbon chain, respectively. The nitrone contains a polar functional group (N–O) and two aromatic rings, which serve to generate both polar and dispersion forces. Consequently, these findings indicate that fatty acid methyl esters may possess

• considerable promise as environmentally friendly solvents for cycloaddition reactions. Moreover, as pointed out by Gil et al., the δP and δH values for methyl esters of saturated fatty acids decrease with increasing chain length [100]. Consequently, the capacity of methyl laurate molecules to direct electric

Synthetic study toward vibralactone

• Liang Shi,
• Jiayi Song,
• Yiqing Li,
• Jia-Chen Li,
• Shuqi Li,
• Li Ren,
• Zhi-Yun Liu and
• Hong-Dong Hao

Beilstein J. Org. Chem. 2025, 21, 2376–2382, doi:10.3762/bjoc.21.182

• cyclopentene ring containing an all-carbon quaternary center [14], and inhibits pancreatic lipase with an IC50 of 0.4 µg/mL. Several congeners with varying oxidation state, as well as related β-hydroxy acids or esters have also been isolated from the culture broth of the basidiomycete [15][16][17][18][19][20

• ][21]. Additionally, a series of vibralactone homodimers and oxime esters 10–12 were reported by the groups of Liu and Zhang, respectively [22][23]. Through modification of the primary hydroxy group, a structure-based optimization of vibralactone (6) was carried out by Liu and co-workers and yielded

Recent advances in Norrish–Yang cyclization and dicarbonyl photoredox reactions for natural product synthesis

• Peng-Xi Luo,
• Jin-Xuan Yang,
• Shao-Min Fu and
• Bo Liu

Beilstein J. Org. Chem. 2025, 21, 2315–2333, doi:10.3762/bjoc.21.177

• intermediate is also capable of cyclization through radical coupling to form cyclobutanol D, a process systematically expanded upon by Yang's group at the University of Chicago [4], which later became known as the Norrish–Yang cyclization. In recent years, dicarbonyls, specifically 1,2-diketones, α-keto esters

• -diketones, α-keto esters, α-keto amides, 1,4-quinones, and 1,2-quinones, emphasizing their unique roles in constructing diverse substructures. However, the reaction faces challenges in terms of regioselectivity and stereoselectivity, which are mainly attributed to the influence of substrate structure

Halogenated butyrolactones from the biomass-derived synthon levoglucosenone

• Johannes Puschnig,
• Martyn Jevric and
• Ben W. Greatrex

Beilstein J. Org. Chem. 2025, 21, 2297–2301, doi:10.3762/bjoc.21.175

• been reported in a 12-step procedure starting with glucose in an overall yield of 2% [24]. Enol esters [25], enolates [26], enamines [27][28], and silyl enol ethers [29], some of which can be derived from LGO, have been used in electrophilic fluorination and trifluoromethylation strategies. It was

Enantioselective radical chemistry: a bright future ahead

• Anna C. Renner,
• Sagar S. Thorat,
• Hariharaputhiran Subramanian and
• Mukund P. Sibi

Beilstein J. Org. Chem. 2025, 21, 2283–2296, doi:10.3762/bjoc.21.174

• enantioselectivity. New catalytic methods have been developed by merging photoenzymatic catalysis with small-molecule photoredox catalysis. Enantioselective radical acylation reactions of N-hydroxyphthalimide esters and aldehydes, yielding α-substituted ketones, were catalyzed by a radical acyl transferase (an

• was the use of ferrocene as a redox mediator, which played an important role in preventing substrate decomposition under the electrochemical conditions. An electrochemical method enabled regio- and enantioselective radical reactions of silyl polyenolates with racemic α-branched esters, yielding

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

• products and pharmaceutical agents. In 2013, Chan and co-workers reported a ligand-controlled cycloisomerization of 1,7-enyne esters affording the selective synthesis of cis-tetrahydropyridinones and δ-diketones (Scheme 16) [24]. When NHC-ligated gold catalysts were employed, a cascade sequence comprising

• intermediate 76 to drive hydrolysis. This methodology tolerates structurally diverse 1,7-enyne esters and generates defined cis-1,2,3,6-tetrahydropyridine scaffolds, which serve as synthetic intermediates for complex natural products and pharmacologically relevant heterocyclic frameworks. In 2016, Jiang group

• derivatives. BiCl3-catalyzed cycloisomerization of tryptamine-ynamide derivatives. Au(I)-mediated substituent-controlled cycloisomerization of 1,6-enynes. Ligand-controlled regioselective cyclization of 1,6-enynes. Ligand-dependent cycloisomerization of 1,7-enyne esters. Ligand-controlled cycloisomerization

Research towards selective inhibition of the CLK3 kinase

• Vinay Kumar Singh,
• Frédéric Justaud,
• Dabbugoddu Brahmaiah,
• Nangunoori Sampath Kumar,
• Blandine Baratte,
• Thomas Robert,
• Stéphane Bach,
• Chada Raji Reddy,
• Nicolas Levoin and
• René L. Grée

Beilstein J. Org. Chem. 2025, 21, 2250–2259, doi:10.3762/bjoc.21.172

• reported in Figure 4. The four acids 10a, 10b, 13a, and 13b demonstrated a significant activity against CLK1 with very low to no action on the other selected kinases. On the other hand, the corresponding esters 9 and 12 were found to be not significantly active against the tested kinases. Indeed, we failed

• addition of the terminal acid significantly reinforces the interaction of our new molecules with CLK3, probably through a salt bridge with lysine 241. Logically, the corresponding esters are found to be inactive. Finally, in order to complete our profiling of VS-77, we then measured its activity against

A chiral LC–MS strategy for stereochemical assignment of natural products sharing a 3-methylpent-4-en-2-ol moiety in their terminal structures

• Rei Suo,
• Raku Irie,
• Hinako Nakayama,
• Yuta Ishimaru,
• Yuya Akama,
• Masato Oikawa and
• Shiro Itoi

Beilstein J. Org. Chem. 2025, 21, 2243–2249, doi:10.3762/bjoc.21.171

• . (a) Synthetic (2S,3S)-8, (2S,3R)-9, (2R,3R)-10, and (2R,3S)-11 and (b) C9–C12 fragment 7 derived from 1. (A) General strategy for the preparation of the fragment from an MPO-containing natural product. (B) Synthesis of esters 4–6, each as a mixture of four stereoisomers. Preparation of the C9–C12

A m-quaterphenyl probe for absolute configurational assignments of primary and secondary amines

• Yuka Takeuchi,
• Mutsumi Kobayashi,
• Yuuka Gotoh,
• Mari Ikeda,
• Yoichi Habata,
• Tomohiko Shirai and
• Shunsuke Kuwahara

Beilstein J. Org. Chem. 2025, 21, 2211–2219, doi:10.3762/bjoc.21.168

• Shibazono, Narashino, Chiba 275-0023, Japan Research Center for Materials with Integrated Properties, Toho University, 2-2-1 Miyama, Funabashi, Chiba 274-8510, Japan 10.3762/bjoc.21.168 Abstract We report a method for determining the absolute configurations of chiral amino alcohols, amino acid esters, and

• amines. In this work, we report that the method was applied to chiral amino alcohols and amino acid esters. We also applied the method to chiral secondary amines, for which it is generally difficult to determine the absolute configuration due to the conformational complexity of their derivatives [33]. By

• esters in the presence of K2CO3 in CH3CN (Scheme 1). The quaternary ammonium salt conjugates 2f–h were also prepared by reacting 1 with chiral secondary amines under similar conditions. It is reported that the central biphenyl moiety of amines and ammonium salts with seven-membered rings freely rotates

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

• isomerization and hydrogenation (Scheme 70, route b2). The accepted mechanism of the rehydration of HMF under acidic conditions leading to the formation of levulinic acid and formic acid proposed by Horvat [224] is depicted in Scheme 71. Levulinic acid can be converted into various derivatives, such as esters

• , amides, lactones, acrylic acid, etc. (Scheme 72) and is therefore a key intermediate in the synthesis of pharmaceuticals, agrochemicals, and other specialty chemicals. Levulinate esters, used as a solvent or as biofuels, are obtained by esterification under acid catalysis, e.g., with a sulfuric acid

• -modified ultra-stable Zeolite Y (SY) [225] or PdNPs-TiO2/Al2O3/SiO2 [226]. Conversion to other carboxylic acids: Valeric acid (VA) and valerate esters (VEs), also named pentanoic acid or esters, are targeted as fuel additives and value-added chemicals. They are obtained by hydrogenation of levulinic acid

Switchable pathways of multicomponent heterocyclizations of 5-amino-1,2,4-triazoles with salicylaldehydes and pyruvic acid

• Yana I. Sakhno,
• Oleksander V. Buravov,
• Kostyantyn Yu. Yurkov,
• Anastasia Yu. Andryushchenko,
• Svitlana V. Shishkina and
• Valentyn A. Chebanov

Beilstein J. Org. Chem. 2025, 21, 2030–2035, doi:10.3762/bjoc.21.158

• also was described in several other publications [13][14][15]. On the other hand, three-component reactions of aminoazoles, salicylaldehyde, and esters (or amides) of acetoacetic acid with isolation of other types of heterocylic compounds were described in some papers [16][17]. Our early works were

Aryl iodane-induced cascade arylation–1,2-silyl shift–heterocyclization of propargylsilanes under copper catalysis

• Rasma Kroņkalne,
• Rūdolfs Beļaunieks,
• Armands Sebris,
• Anatoly Mishnev and
• Māris Turks

Beilstein J. Org. Chem. 2025, 21, 1984–1994, doi:10.3762/bjoc.21.154

• an internal nucleophile (O-, N-) and reductive elimination affords the arylated product 8 and regenerates the Cu(I) catalyst. The added base (B:) traps the H+, generated in this catalytic cycle. In the case of tert-butyl esters (7: R = COOt-Bu) an equivalent of isobutylene gas is released as a side

Photochemical reduction of acylimidazolium salts

• Michael Jakob,
• Nick Bechler,
• Hassan Abdelwahab,
• Fabian Weber,
• Janos Wasternack,
• Leonardo Kleebauer,
• Jan P. Götze and
• Matthew N. Hopkinson

Beilstein J. Org. Chem. 2025, 21, 1973–1983, doi:10.3762/bjoc.21.153

• manifold with carboxylic acid derivatives, numerous coupling processes affording ketone products have been developed. Since the initial report from Scheidt and co-workers using 4-alkyl-substituted Hantzsch esters as coupling partners [31][32][33][34][35][36], several alkyl radical sources have been

Rhodium-catalysed connective synthesis of diverse reactive probes bearing S(VI) electrophilic warheads

• Scott Rice,
• Julian Chesti,
• William R. T. Mosedale,
• Megan H. Wright,
• Stephen P. Marsden,
• Terry K. Smith and
• Adam Nelson

Beilstein J. Org. Chem. 2025, 21, 1924–1931, doi:10.3762/bjoc.21.150

• -diazoamides 1. Finally, Pd-catalysed cross-coupling with warhead-substituted phenyl iodides gave, in low to moderate yield, the required α-diazoamide substrates 2 (referred to individually as D1–5 below). Whilst the Pd-catalysed arylation of α-diazoamides and esters is known [15][16][17][18][19], its

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

• synthetic organic chemistry and pharmaceutical applications due to their diverse biological activities. In this study, we synthesized three novel glycidyl esters of phosphorus acids 1–3 via the condensation of chlorophosphine oxides or phosphorus oxychloride with glycidol in the presence of a base

• . These findings provide important insights into the synthesis, cytotoxic activity, and biochemical reactivity of glycidyl esters of phosphorus acids, underscoring their potential as lead structures for further development in anticancer drug discovery and pharmaceutical research. Keywords: alkylating

• chemical literature regarding the biological activity (including anticancer properties) of phosphoric esters, reports on biological studies of systems based on the P=O fragment and oxirane skeletons are less common. Nevertheless, systems containing both of the mentioned structural motifs are rarely

Photoswitches beyond azobenzene: a beginner’s guide

• Michela Marcon,
• Christoph Haag and
• Burkhard König

Beilstein J. Org. Chem. 2025, 21, 1808–1853, doi:10.3762/bjoc.21.143

• reductive cross-coupling of benzyl halides when substituents prone to reduction (CN, esters) are present (Scheme 12C). The Ullman–Goldberg coupling of 41b with Boc-hydrazine followed by deprotection and oxidation then affords 35 [55]. Asymmetric diazocines can be synthesised by Sonogashira cross-coupling

Preparation of a furfural-derived enantioenriched vinyloxazoline building block and exploring its reactivity

• Madara Darzina,
• Anna Lielpetere and
• Aigars Jirgensons

Beilstein J. Org. Chem. 2025, 21, 1737–1741, doi:10.3762/bjoc.21.136

• amino alcohols derived from furfural and ʟ- or ᴅ-valinol were subjected to Torii-type ester electrosynthesis to obtain the corresponding unsaturated esters. These served as key intermediates to prepare (S)- and (R)-enantioenriched unsaturated amides by N-Alloc deprotection which induced concomitant

• applications to functional materials, pharmaceutically relevant compounds, and agrochemicals [8][9][10][11][12][13][14][15][16][17]. In our recent work, we have developed a Torii-type electrosynthesis of unsaturated esters 3a–c starting from furfural (1) and amino alcohol conjugates 2a–c [18]. The process

• oxidation in methanol in batch electrolysis conditions, providing unsaturated esters S-3d and R-3d, respectively (Scheme 2). The previously used one-reactor two-step conditions were found to be productive for the electrosynthesis of S-3d, requiring the addition of acetic acid for the intermediate spiroketal

3,3'-Linked BINOL macrocycles: optimized synthesis of crown ethers featuring one or two BINOL units

• Somayyeh Kheirjou,
• Jan Riebe,
• Maike Thiele,
• Christoph Wölper and
• Jochen Niemeyer

Beilstein J. Org. Chem. 2025, 21, 1719–1729, doi:10.3762/bjoc.21.134

• the approach via Suzuki coupling, we employed the previously reported BINOL-diiodide 1 [52], which was reacted with bisboronic acids (see Figure 3a). Here we chose bisboronic esters 75/6/7/8 which feature dimethylphenyl groups that are linked via penta/hexa/hepta/octaethylene glycol chains (throughout

Approaches to stereoselective 1,1'-glycosylation

• Daniele Zucchetta and
• Alla Zamyatina

Beilstein J. Org. Chem. 2025, 21, 1700–1718, doi:10.3762/bjoc.21.133

• -configuration on the glycosyl acceptor side was “retained” from the 1,2-orthoester progenitor. The nature of the protecting groups proved to be critical for the glycosylation outcome: the use of bulkier benzoyl esters, as in the phenyl 1,2-orthoester 19, led to a lower yield (36%) of the 1,1'-linked product 20

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

• synthesis of esters of phosphonous or alkylphosphinic acids [33][34][35]. Only a single application of cesium hypophosphite was shown in the literature. CsH2PO2 was prepared in situ and used for formation C–P bond by radical addition to unsaturated carboxylic acids [36 ]To summarize the above, it is crucial

Photocatalysis and photochemistry in organic synthesis

• Timothy Noël and
• Bartholomäus Pieber

Beilstein J. Org. Chem. 2025, 21, 1645–1647, doi:10.3762/bjoc.21.128

• of alkenylboronic esters using energy transfer catalysis [26]. Gualandi and co-workers leveraged a combination of photoredox and HAT catalysis to realize the intramolecular nucleophilic amidation of alkenes with β-lactams [27]. Further, Luridiana and colleagues developed a method for the alkylation

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

• 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