Efficient solid-phase synthesis and structural characterization of segetalins A–H, J and K

• Liangyu Liu,
• Wanqiu Lu,
• Quanping Guo and
• Zhaoqing Xu

Beilstein J. Org. Chem. 2025, 21, 2612–2617, doi:10.3762/bjoc.21.202

• ) and G (7) using a pseudoprolinic acid strategy to induce cis-amide bond formation, followed by desulfurization [19]. Despite achieving cyclization, this route involves intricate procedures, expensive starting materials, and has limited applicability to other segetalins. Given the limitations of

Silica gel with covalently attached bambusuril macrocycle for dicyanoaurate sorption from water

• Michaela Šusterová and
• Vladimír Šindelář

Beilstein J. Org. Chem. 2025, 21, 2604–2611, doi:10.3762/bjoc.21.201

• (HOBt) and 1,3-diisopropylcarbodiimide (DIC) in DMF, resulting in SG-NHCO-BU1 with BU1 covalently attached through amide bonds (Scheme 1). The material was thoroughly washed with DMF, water, and methanol to remove byproducts and unreacted BU1. The grafting reaction was conducted using a 9:1 (w/w) ratio

• groups onto the silica gel surface, confirming the formation of a-SG. Upon modification of a-SG with BU1, additional bands characteristic of BU1 appeared. When comparing BU1 with the SG-NHCO-BU1 material, the C=O vibration band shifted from 1703 cm−1 to 1696 cm−1 indicating the formation of an amide bond

• . Additionally, a new absorption band at 1558 cm−1 was observed in the spectra of SG-NHCO-BU1 further confirming covalent attachment of BU1 through an amide bond. In the case of SG-BU1, a C=O vibrational band is observed at 1705 cm−1, which corresponds to the vibration of the C=O of BU1 carboxylic acid groups

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

• , particularly the synergistic combination of N-heterocyclic carbenes (NHCs) with organic photocatalysts, has opened new avenues in molecular construction, particularly for the novel, practical preparation of carbonyl group-containing compounds [13][14][15][16]. These ubiquitous ketone, ester, and amide

• , and advanced optical and energy materials. Review Visible-light-driven NHC/4CzIPN-catalyzed reactions Recently, Shu and co-workers developed a direct and innovative preparation of highly functionalized aryl amide derivatives 3 from aryl aldehydes 1 and substituted imines 2 under mild conditions in the

• of single-electron NHC catalysis by incorporating oxidatively generated aryloxymethyl radicals A as a key intermediate. A variety of γ-aryloxy ketones 12 were successfully prepared in the presence of NHC (15 mol %), photocatalyst (2 mol %), using 467 nm LED and a combination of alkene 11, amide 9

Ni-promoted reductive cyclization cascade enables a total synthesis of (+)-aglacin B

• Si-Chen Yao,
• Jing-Si Cao,
• Jian Xiao,
• Ya-Wen Wang and
• Yu Peng

Beilstein J. Org. Chem. 2025, 21, 2548–2552, doi:10.3762/bjoc.21.197

• File 1). The generated ester 10 was then converted into the corresponding acyl chloride by saponification and subsequent reaction with pivaloyl chloride. The resulting acyl chloride was then trapped by (S)-4-phenyl-2-oxazolidinone (11) to produce the desired α,β-unsaturated amide 7. Next, the

Synthesis and characterization of a isothiouronium-calix[4]arene derivative: self-assembly and anticancer activity

• Giuseppe Granata,
• Loredana Ferreri,
• Claudia Giovanna Leotta,
• Giovanni Mario Pitari and
• Grazia Maria Letizia Consoli

Beilstein J. Org. Chem. 2025, 21, 2535–2541, doi:10.3762/bjoc.21.195

• into the calixarene skeleton to develop anticancer derivatives, including proline [34], carbonyl amide [35], glycoureido [36], ureido [37], picolylamine [38], 5-bromopentyltrimethylammonium bromide and 3-bromopropyltriphenylphosphonium bromide [39], among others. Isothiouronium salts represent another

Isoorotamide-based peptide nucleic acid nucleobases with extended linkers aimed at distal base recognition of adenosine in double helical RNA

• Grant D. Walby,
• Brandon R. Tessier,
• Tristan L. Mabee,
• Jennah M. Hoke,
• Hallie M. Bleam,
• Angelina Giglio-Tos,
• Emily E. Harding,
• Vladislavs Baskevics,
• Martins Katkevics,
• Eriks Rozners and
• James A. MacKay

Beilstein J. Org. Chem. 2025, 21, 2513–2523, doi:10.3762/bjoc.21.193

• functionalized. We noted that isoorotic acid offered an opportune core from which to prepare extended nucleobase monomers through amide bond formation (Figure 3a) [34]. Secondly, the work began with the initial goal to find an extended nucleobase scaffold capable of strong binding to A and then reverse its point

• nucleobases that showed enhanced triplex stability through cooperative effects compared to the control thymine base. In a follow up study, the pendant amide was removed from the Io core to determine the importance of the third hydrogen bond. To our surprise, these second-generation Io derivatives retained

• containing functional groups in the linker including an amine (Db1), an amide based on the V linker (Db2), and an aniline (Db3). In the case of Db1, physiological conditions would afford a protonated amine functionality that may allow for stabilization of the triplex through electrostatic interactions

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

• 1,3-dipole and/or dipolarophile and therefore, in some cases, cis-diastereoselectivity arises [85][114][115][116][117]. For instance, in the [3 + 2] cycloaddition reactions examined in earlier studies, intramolecular H-bonding, facilitated by the amide or alcohol functionality present in the nitrone

• optimized [3 + 2] cycloaddition conditions. The primary strategy for the selection of these compounds as catalysts is predicated on their capacity to function as H-bond acceptors and/or H-bond donors. As has been documented in previous research, imine-based templates or [2]rotaxane that possess an amide

Rotaxanes with integrated photoswitches: design principles, functional behavior, and emerging applications

• Jullyane Emi Matsushima,
• Khushbu,
• Zuliah Abdulsalam,
• Udyogi Navodya Kulathilaka Conthagamage and
• Víctor García-López

Beilstein J. Org. Chem. 2025, 21, 2345–2366, doi:10.3762/bjoc.21.179

• form selective hydrogen bonds between the carbonyl oxygen of the fumaramide unit and the N–H groups of benzylic amide rings. Upon isomerization to the cis isomer, the hydrogen-bonding interactions are weakened, enabling the macrocycle to migrate to a second recognition station [61]. Despite their

• delivery and microscale chemical reactions, by allowing the controlled merging of droplets containing different reactants without the need for traditional reaction vessels. Furthermore, Zhu and co-workers developed a rotaxane-based fluorescence switch in which photoinduced shuttling of the benzylic amide

• macrocycle occurs along a thread containing fumaramide and succinic amide ester units as recognition sites, with highly fluorescent perylene bisimide and pyrene serving as stoppers [67]. The macrocycle features two pyridine units that, upon protonation, effectively quench the fluorescence of both

Comparative analysis of complanadine A total syntheses

• Reem Al-Ahmad and
• Mingji Dai

Beilstein J. Org. Chem. 2025, 21, 2334–2344, doi:10.3762/bjoc.21.178

• , which continued with an amide-ketone condensation to finally produce 31 in this highly efficient one-step biomimetic cascade sequence. The secondary amine of 31 was selectively protected as a Boc carbamate and the dihydropyridone moiety was oxidized to a pyridone with Pb(OAc)4. Pyridone 32 was prepared

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

• pyrrolidine-derived phenyl keto amide substrate 91 with blue LEDs produces the pyrrolidine-fused 4-oxazolidinone (N,O-acetal) 92, precluding preparation of the pyrrolidine analog of lycoplatyrine A (94) by this method. Compound 92 is presumably formed via either the radical mechanism [41] or possibly

• . Asymmetric total synthesis of lycoplatyrine A. Photoreaction of pyrrolidine-derived phenyl keto amide. Photoredox reactions of naphthoquinones. Synthetic study toward γ-rubromycin. Substituent-dependent conformational preferences. Total synthesis of preussomerins EG1, EG2, and EG3. Acknowledgements This

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

• acted as nucleophile, the stable imine–gold–aryl cation–π–π interaction precluded rearrangement and promoted the capture of imine to form spiro[indoline-3,3'-pyridine] derivatives 67. The Ph3PAuCl/AgNTf2-catalyzed cyclization of N-propargyl-tethered amide enynes efficiently afforded four distinct

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

• ], sultam-fused pyridinone [106] as well as cyclicphosphinic amide [107] were produced by electrochemical cyclization of alkyne. Especially, the electrochemical organic transformation of alkyne was widely applied to build five-membered rings. For example, benzimidazole-fused isoindole was generated by

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

• HFO with benzoic acid amide or furan-2-carboxamide in 1:1 molar ratio at 70 °C for 4–8 h (Scheme 42, path c) [132]. The reaction of HFO with 2-methylfuran in a 1:2.2 molar ratio in diethyl ether solution at room temperature in the presence of catalytic amounts of perchloric acid for 5 hours led to the

• synthesize photoluminescence-active polyamides from renewable furfural and 2,5-furandicarboxylic acid with diamine and isocyanide (Scheme 62). The intramolecular hydrogen bonding between the secondary amide and furan oxygen atom promote the strong fluorescence of the polyamides. These furfural-based

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

α-Ketoglutaric acid in Ugi reactions and Ugi/aza-Wittig tandem reactions

• Vladyslav O. Honcharov,
• Yana I. Sakhno,
• Olena H. Shvets,
• Vyacheslav E. Saraev,
• Svitlana V. Shishkina,
• Tetyana V. Shcherbakova and
• Valentyn A. Chebanov

Beilstein J. Org. Chem. 2025, 21, 2021–2029, doi:10.3762/bjoc.21.157

• compared to compounds 5, which can be clearly seen in the spectrum of compound 8h with both substituted ortho-positions of the amine moiety. In our opinion, this indicates the presence of rotamerism [59][60] caused by the restricted rotation of the sterically hindered amide group. The 1H NMR spectra of

• –7.81 ppm, corresponding to 16 protons, multiplets for CH2 groups at 1.78–2.96 ppm, and two signals for tert-butyl groups protons at 1.21–1.24 ppm. The increase in signal multiplicity compared to compounds 5 could indicate the presence of diastereomerism and restricted amide rotation in compounds 6. In

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

• amino acids [8][9][10]. Sets of reactive probes are generally prepared using robust reactions, most usually amide formation, chosen from the toolkit that currently dominates medicinal chemistry [11] which may, in turn, limit probe structural diversity. We have developed a unified connective approach for

• -catalysed reaction between an α-diazo amide substrate bearing a warhead, and a co-substrate. The structural diversity of the probe set was increased by the multiple possible reaction modes of rhodium carbenoids, which enabled many different co-substrate classes and catalyst-driven selectivities to be

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

• oxidation of amide and other amino acid side‐chain fragments. By tracking changes in this oxidation signal upon addition of an alkylating agent, we can infer whether the agent has effectively reacted with (and thus structurally altered) the protein. As illustrated by the black trace in the LSV plot, pure

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

Synthesis of chiral cyclohexane-linked bisimidazolines

• Changmeng Xi,
• Qingshan Sun and
• Jiaxi Xu

Beilstein J. Org. Chem. 2025, 21, 1786–1790, doi:10.3762/bjoc.21.140

• -protected amino group. On the basis of the previous report [28], a possible reaction mechanism is presented in Scheme 3. The reaction of triphenylphosphine oxide and triflic anhydride first generates an activating agent, the Hendrickson reagent (A). The amide in cyclohexane-1,2-dicarboxamides 4

Research progress on calixarene/pillararene-based controlled drug release systems

• Liu-Huan Yi,
• Jian Qin,
• Si-Ran Lu,
• Liu-Pan Yang,
• Li-Li Wang and
• Huan Yao

Beilstein J. Org. Chem. 2025, 21, 1757–1785, doi:10.3762/bjoc.21.139

• Biotin-SAC4A by modifying SAC4A with biotin. (Figure 16) [124]. Monocarboxylated azocalixarene and aminated biotin were synthesized. Subsequently, using a coupling agent, the carboxyl group of the azocalixarene was modified through amidation to obtain biotin-modified SAC4A. The formation of amide bonds

Unique halogen–π association detected in single crystals of C–N atropisomeric N-(2-halophenyl)quinolin-2-one derivatives and the thione analogue

• Mai Uchibori,
• Nanami Murate,
• Kanako Shima,
• Tatsunori Sakagami,
• Ko Kanehisa,
• Gary James Richards,
• Akiko Hori and
• Osamu Kitagawa

Beilstein J. Org. Chem. 2025, 21, 1748–1756, doi:10.3762/bjoc.21.138

• intermolecular interaction (halogen bonding) between chiral compounds possessing an amide group and a thioamide group are quite rare [21]. We were curious as to whether the chirality (racemate/optically pure form)- and the functional group (C=O/C=S)-dependent halogen bonds found in I and II are also observed in

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

• ][24] (Scheme 1). The proposed strategy relied on the N-deprotection of the intermediate ester 3d inducing O-to-N rearrangement to form amide 5 as a precursor of vinyloxazoline 6. For this purpose, Alloc (allyloxycarbonyl) turned out to be a suitable N-protecting group as it was compatible with the

• trans-isomer of amide 5. Results and Discussion The protected furfuryl amino alcohols S-2d and R-2d were prepared by reductive amination of furfural (1) with ʟ- and ᴅ-valinol followed by N-protection with Alloc-Cl (Scheme 2). The amino alcohols S-2d and R-2d were then subjected to electrochemical

• material S-3d but provided a mixture of cis- and trans-amides cis-S-5 and trans-S-5 (Scheme 3). The use of PdCl2(S-BINAP) complex as a precatalyst resulted in a longer reaction time and an exclusive formation of amide trans-S-5 with isomerized double bond (Scheme 4). The amide trans-R-5 was prepared

Catalytic asymmetric reactions of isocyanides for constructing non-central chirality

• Jia-Yu Liao

Beilstein J. Org. Chem. 2025, 21, 1648–1660, doi:10.3762/bjoc.21.129

• ]. Encouraged by the above results, we turned our attention to biaryl lactams [49]. However, in this case, the inherent resonance stability of the amide bond makes the ring-opening process rather challenging. To solve this problem, we envisioned that a cooperative catalytic system merging silver catalysis and

pH-Controlled isomerization kinetics of ortho-disubstituted benzamidines: E/Z isomerism and axial chirality

• Ryota Kimura,
• Satoshi Ichikawa and
• Akira Katsuyama

Beilstein J. Org. Chem. 2025, 21, 1568–1576, doi:10.3762/bjoc.21.120

• substitution of an ortho-disubstituted benzamide (DiBA) increases the rotational barrier of the C–N and C–N/C–C concerted rotation (Figure 1a,b) [20]. The observation can be explained mainly by the double-bond nature of the chalcogen amide C–N bond, which is attributed to a zwitterionic resonance structure of

• chalcogen amide. It has been shown that a late periodic chalcogen amide has a lower energy π* orbital (C=S or C=Se), resulting in an increase in the contribution of the zwitterionic resonance structure [21][22][23]. Based on this consideration, an ortho-disubstituted benzamidine, which is generated by

• various fields, such as functional materials, biological probes, and drugs. a) Structural features of DiBA. b) Resonance structure of the amide moiety of DiBA. c) Molecular form and protonated structure of ortho-disubstituted benzamidine. Rotational barriers of 2-bromo-N,N,6-trimethylbenzimidamide and its

Azide–alkyne cycloaddition (click) reaction in biomass-derived solvent Cyrene^TM under one-pot conditions

• Zoltán Medgyesi and
• László T. Mika

Beilstein J. Org. Chem. 2025, 21, 1544–1551, doi:10.3762/bjoc.21.117

• , a wide range of organic reactions, e.g., urea and amide formation [32][33], amide coupling [34], aldol condensation [35], C–H difluoromethylation [36], aromatic substitution [37], and MOFs synthesis [38] were demonstrated in CyreneTM. Very recently, Fasano and Citarella first reported a CuAAC