Bioinspired total syntheses of natural products: a personal adventure

• Zhengyi Qin,
• Yuting Yang,
• Nuran Yan,
• Xinyu Liang,
• Zhiyu Zhang,
• Yaxuan Duan,
• Huilin Li and
• Xuegong She

Beilstein J. Org. Chem. 2025, 21, 2048–2061, doi:10.3762/bjoc.21.160

• additions, respectively. This result suggests that the addition fully went from the upper face and the left-oriented isopropyl showed no steric effect to control the regioselectivity. With free amide 50a and 50b in hand, the mixture was treated with DBU to promote aza-Michael addition to afford lactam

Continuous-flow-enabled intensification in nitration processes: a review of technological developments and practical applications over the past decade

• Feng Zhou,
• Chuansong Duanmu,
• Yanxing Li,
• Jin Li,
• Haiqing Xu,
• Pan Wang and
• Kai Zhu

Beilstein J. Org. Chem. 2025, 21, 1678–1699, doi:10.3762/bjoc.21.132

• -flow configurations demonstrate superior safety and efficiency. While the synthetic significance of nitration is underscored by the broad utility of nitro derivatives, persistent technical challenges including regioselectivity control, over-nitration phenomena, and substrate oxidation side reactions

• aliphatic counterparts) due to their predictable electrophilic substitution mechanisms and relatively mild reaction conditions, which enable superior controllability and regioselectivity. Unlike aromatic nitrations that predominantly follow ionic mechanisms, aliphatic systems governed by free radical

• regioselectivity and product purity. Nitrating reagents: Nitrating reagents play a pivotal role in determining the efficiency, selectivity, and safety of nitration processes, with their selection being fundamentally dependent on the nature of the substrate and desired reaction outcomes. Analytical data (Figure 4a

Facile synthesis of hydantoin/1,2,4-oxadiazoline spiro-compounds via 1,3-dipolar cycloaddition of nitrile oxides to 5-iminohydantoins

• Juliana V. Petrova,
• Varvara T. Tkachenko,
• Victor A. Tafeenko,
• Anna S. Pestretsova,
• Vadim S. Pokrovsky,
• Maxim E. Kukushkin and
• Elena K. Beloglazkina

Beilstein J. Org. Chem. 2025, 21, 1552–1560, doi:10.3762/bjoc.21.118

• regioselectivity of the cycloaddition reaction between nitrile oxides and C=N bonds can be rationalized by considering the relative electronegativities of the terminal elements and the distribution of electron density in the frontier orbitals of the reagents [35]. The electrons are preferentially located on the

Ambident reactivity of enolizable 5-mercapto-1H-tetrazoles in trapping reactions with in situ-generated thiocarbonyl S-methanides derived from sterically crowded cycloaliphatic thioketones

• Grzegorz Mlostoń,
• Małgorzata Celeda,
• Marcin Palusiak,
• Heinz Heimgartner,
• Marta Denel-Bobrowska and
• Agnieszka B. Olejniczak

Beilstein J. Org. Chem. 2025, 21, 1508–1519, doi:10.3762/bjoc.21.113

• ], were analogously treated with CH2N2 at ca. 0 °C and the expected cycloadducts 2c and 2d were formed with complete regioselectivity, and subsequently could be isolated in good yields without a remarkable decomposition (Scheme 3). Thermal decomposition of 2a and 2b, and the behavior of the corresponding

• regioselectivity in high yields. Upon heating to 65 °C in toluene solution, in analogy to the well-known compounds 2a and 2b, they extruded N2 and the in situ-generated reactive thiocarbonyl S-methanides 1c and 1d, in absence of any trapping reagent, underwent 1,3-dipolar electrocyclization yielding the

• ), respectively). Ambident reactivity of 5-mercapto-1H-tetrazoles 4 towards dimethyl 2-arylcyclopropane dicarboxylates 3; formation of the S- and N-insertion products 5 and 6, respectively [15]. Regioselectivity of [3 + 2] cycloadditions of diazomethane with adamantanethione (7a) [22][24][25], and sterically

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

• substitution pattern on the regioselectivity and stereoselectivity of the reactions. A Review article by Papis and co-workers discusses various copper(II) triflate-catalyzed multicomponent reaction types [2]. Therein, the synthesis of cyclic and acyclic compounds, as well as three-component and four-component

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

• after deprotonation of a suitably functionalised ether at the α-carbon. Therefore, a stabilising group must be incorporated to control regioselectivity of the deprotonation as well as to increase the acidity of the α-hydrogen. Mordini et al. showed that even weakly stabilising groups such as phenyl

• regioselectivity of the Friedel–Crafts alkylation to the para-position, forming exclusively (or significant amounts of) 3,3-diaryloxetanes. In 2017, Vanderwal and co-workers published a novel, facile synthesis of furans 181 and pyrroles 185 from 3-(2-oxoalkylidene)oxetanes 179, precursors which are readily

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

• effectively abstracts a hydrogen atom from the polyolefin substrate, demonstrating notable regioselectivity. The xanthylation reaction preferentially generates main products 76, and byproducts (77 and 78). Furthermore, the successful implementation of this methodology facilitates the production of a diverse

• bonds due to their inherent polarity. Furthermore, amidyl radicals encounter difficulties in regioselectivity when applied to structurally complex C–H substrates, which limits their utility in modifying intricate molecular architectures. Future advancements are anticipated through structural

• modifications of amidyl radicals aimed at optimizing their polarity via electronic effects, which may enhance their effectiveness in hydrogen abstraction from electron-deficient substrates. Additionally, strategies to optimize steric effects could improve their regioselectivity in hydrogen abstraction from

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

• radical cascade cyclization, where the α-carbonyl bromides serve as alkyl radical precursors, enabling the synthesis of complex lactam structures with excellent chemo- and regioselectivity. The system demonstrated a broad substrate scope, encompassing various dienes and α-carbonyl bromides. It showed

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

• molecular architectures in pharmaceuticals, polymers, and agrochemicals. Despite advancements in directing group (DG) methodologies and computational approaches, predicting accurate regioselectivity in C–H activation poses significant difficulties due to the diversity and complexity of organic compounds

• reliable regioselectivity predictions that are essential for accelerating innovation in materials science and medicinal chemistry. Keywords: C–H activation; chemical synthesis planning; directing groups; quantum mechanics; regioselectivity prediction; Introduction The activation and functionalization of

• , 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

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

• . The synthesis commenced with the treatment of precursor 92, obtained in three steps from ethylene glycol, with MeMgBr and catalytic 94/CuBr, yielding the 1,4-addition product 93 in 96% yield and excellent regioselectivity (ee 98%) (Scheme 15). The authors highlighted the scalability of this reaction

• CuBr·SMe2, facilitating the formation of deoxypropionate 125 in 80% yield with excellent regioselectivity (>99:1) and stereoselectivity (99:1 dr). Ozonolysis of 125 followed by reductive work up with NaBH4 afforded alcohol 126 in 92% yield. At this stage, the authors explored an alternative procedure for

• subsequent transmetallation with MgBr2·OEt2 yielded the desired magnesium species. Reaction of this reagent with (R)-120 in the presence of CuBr·SMe2 afforded product (–)-128 in 86% yield, with perfect regioselectivity (>99:1) and excellent stereochemistry (98:2 dr). Repeating the sequence of ozonolysis

Investigations of amination reactions on an antimalarial 1,2,4-triazolo[4,3-a]pyrazine scaffold

• Henry S. T. Smith,
• Ben Giuliani,
• Kanchana Wijesekera,
• Kah Yean Lum,
• Sandra Duffy,
• Aaron Lock,
• Jonathan M. White,
• Vicky M. Avery and
• Rohan A. Davis

Beilstein J. Org. Chem. 2025, 21, 1126–1134, doi:10.3762/bjoc.21.90

• engrafted with human erythrocytes, after oral administration of the compounds [5][9]. Triazolopyrazines halogenated on the pyrazine ring represent synthetically useful targets for elaboration of this active scaffold, and the regioselectivity of amine nucleophiles (amongst others) has been explored by Korsik

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

• CO, Jiang and co-workers (2020) reported a Pd-catalyzed hydrocarboxylation of alkynes with high regioselectivity to obtain the corresponding cinnamic acids 281 and 282 in good yields via cyclopalladation intermediate 283 (Scheme 70A) [119]. The method has been scaled up to a gram scale operation

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

• ring was then constructed via an intramolecular reductive Heck reaction from vinyl bromide 10 with exclusive regioselectivity. Considering the strain of forming the 7-membered ring, this highly efficient 7-endo-trig (vs 6-exo-trig) transannular Heck cyclization reaction was remarkable to be realized in

Harnessing tethered nitreniums for diastereoselective amino-sulfonoxylation of alkenes

• Shyam Sathyamoorthi,
• Appasaheb K. Nirpal,
• Dnyaneshwar A. Gorve and
• Steven P. Kelley

Beilstein J. Org. Chem. 2025, 21, 947–954, doi:10.3762/bjoc.21.78

• Abstract We present the first examples of alkene amino-sulfonoxylation reactions that leverage the unique reactivity of carbamate tethered N-alkoxy nitrenium ions. In almost all cases examined, the reactions deliver product with exquisite regioselectivity and diastereoselectivity. The protocols followed

• new alkene amino-sulfonoxylation reaction that leverages the unique reactivity of carbamate tethered N-alkoxy nitrenium ions. In almost all cases examined, the reactions delivered product with exquisite regioselectivity and diastereoselectivity. The protocols followed were operationally very simple

A convergent synthetic approach to the tetracyclic core framework of khayanolide-type limonoids

• Zhiyang Zhang,
• Jialei Hu,
• Hanfeng Ding,
• Li Zhang and
• Peirong Rao

Beilstein J. Org. Chem. 2025, 21, 926–934, doi:10.3762/bjoc.21.75

• promoted by LiHMDS gave alcohol 17 with high regioselectivity (14:1 dr at C17) after an extensive screening of bases (LDA, NaHMDS, KHMDS, etc.). Drawing inspiration from the pioneering work of Birman [38], as well as Newhouse’s applications [18][19], an acylative kinetic resolution of the alcohol was

Recent advances in controllable/divergent synthesis

• Jilei Cao,
• Leiyang Bai and
• Xuefeng Jiang

Beilstein J. Org. Chem. 2025, 21, 890–914, doi:10.3762/bjoc.21.73

• ensuring high regioselectivity. In 2018, the Jiang group developed a regiodivergent synthetic method for indolo[3,2-c]coumarins 10 and benzofuro[3,2-c]quinolinones 9 via controllable palladium(II)-catalyzed carbonylative cyclization (Scheme 3) [21]. When ligand L3 coordinates with the palladium center, the

• , the Shu group developed a catalyst-controlled regioselective and enantioselective hydroamination reaction of electron-deficient alkenes (Scheme 7) [30]. By efficiently regulating the regioselectivity and enantioselectivity of alkene 23 hydrometallation through catalytic systems, they overcame the

• obtained with exclusive regioselectivity and excellent enantioselectivity. Employing a nickel catalyst, α-chiral β-amino acid derivatives 27 were synthesized with single regioselectivity and outstanding enantioselectivity. In the same year, Rong and co-workers reported a highly efficient catalyst

Cu–Bpin-mediated dimerization of 4,4-dichloro-2-butenoic acid derivatives enables the synthesis of densely functionalized cyclopropanes

• Patricia Gómez-Roibás,
• Andrea Chaves-Pouso and
• Martín Fañanás-Mastral

Beilstein J. Org. Chem. 2025, 21, 877–883, doi:10.3762/bjoc.21.71

• the copper–boron bond into 1. The dual functionality of this substrate imposed a question related to the regioselectivity of the Cu–Bpin insertion since it can potentially behave as an α,β-unsaturated ester or an allylic substrate [16][17][18][19]. To shed some light into this issue, we ran the

Regioselective formal hydrocyanation of allenes: synthesis of β,γ-unsaturated nitriles with α-all-carbon quaternary centers

• Seeun Lim,
• Teresa Kim and
• Yunmi Lee

Beilstein J. Org. Chem. 2025, 21, 800–806, doi:10.3762/bjoc.21.63

• catalysis; hydrocyanation; regioselectivity; tosyl cyanide; Introduction Acyclic nitriles that incorporate α-all-carbon quaternary centers are highly valuable structural motifs typically found in natural products, biologically active compounds, and synthetic pharmaceuticals [1][2][3][4][5]. These compounds

• ]. The limited investigation of allene hydrocyanation can be attributed to the significant challenges posed by the two orthogonal π-systems in allenes. These challenges include achieving high regioselectivity and controlling (E)/(Z)-stereoselectivity, as 1,2-addition processes to allenes can generate up

• for the in situ generation of hydrogen cyanide (Scheme 1a). This method achieved high regioselectivity and enantioselectivity, highlighting the potential of allene hydrocyanation for the synthesis of complex nitrile-containing products. In another approach, the Minakata group used electrophilic

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

• ferrocene and ruthenocene via coupling reaction. This method provides an efficient and versatile synthetic approach for producing phosphorylated metallocenes but also aids in interpreting the regioselectivity and reactivity of C−H functionalization in unsymmetric metallocenes. They used a platinum electrode

• , or phenyl groups at the α-position. The researchers noted that the lower yields were due to substrate decomposition or poor conversion rather than regioselectivity issues. Additionally, this method was also suitable for the phosphorylation of ferrocenes. For mechanistic studies, the reaction was

Recent advances in allylation of chiral secondary alkylcopper species

• Minjae Kim,
• Gwanggyun Kim,
• Doyoon Kim,
• Jun Hee Lee and
• Seung Hwan Cho

Beilstein J. Org. Chem. 2025, 21, 639–658, doi:10.3762/bjoc.21.51

• eponymous Tsuji–Trost reaction, they faced a significant limitation: poor regioselectivity with non-symmetrical allylic substrates 2. This constraint led to the predominant development of Pd-catalyzed methods using symmetric 1,3-disubstituted allylic substrates 1 that contain a leaving group in the allylic

• substitution reactions began to develop with the groundbreaking work of Takeuchi and Kashio, and subsequent research has revealed that iridium catalysts behave quite differently from their palladium counterparts [18]. The most notable distinction lies in their contrasting regioselectivity patterns. Palladium

• regioselectivity (SN2/SN2' = >99:1). The reaction with 3-methylbut-2-en-1-yl bromide (15) was particularly noteworthy, as it exhibited superior selectivity compared to the corresponding phosphates. The high efficiency of this protocol was demonstrated through the synthesis of various functionalized alkenes with

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

• catalysis, respectively [86][93]. They extended the scope of the reaction to a wider range of amidines and isocyanides using glyoxylic acid in 50% aqueous solution, with HClO4 as acid catalyst (Scheme 35) [86]. Under these conditions, the yield, the scope, and the regioselectivity of the reaction increased

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

• biologically active compounds, particularly antibacterial and antifungal agents [13][14]. This class of functionalized nitrogen heterocycles is notable for its synthetic versatility, because it shows different nucleophilic positions, making regioselectivity a synthetic challenge. Numerous studies have reported

Beyond symmetric self-assembly and effective molarity: unlocking functional enzyme mimics with robust organic cages

• Keith G. Andrews

Beilstein J. Org. Chem. 2025, 21, 421–443, doi:10.3762/bjoc.21.30

• hydrophobic catalysis as for the macrocycles discussed in the previous section [115], and so remain prone to product inhibition [113], though not exclusively [120]. Size- and regioselectivity are possible [121]. As with the two identical halves of a tennis ball/softball, it is harder to conceive unsymmetric

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

• cyclohexadiene did not react even with acetylacetone, and for 2,3-dimethylbutadiene, target compound 13 was obtained in 41% yield. In all cases, no formation of even trace amounts of the hetero-Diels–Alder reaction adducts II was detected. The regioselectivity of the cycloaddition of methylidene intermediates

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

• -fluorobenzene (see Scheme 2 and Supporting Information File 1 for details). Copper(I)-catalyzed three-component coupling reaction of alkyne 8, THIQ 9, and benzaldehyde, proceeded with exquisite control of regioselectivity to afford 10 in an excellent yield of 92% [43][44][45][46]. This efficient cascade