Dioxazolones as electrophilic amide sources in copper-catalyzed and -mediated transformations

• Seungmin Lee,
• Minsuk Kim,
• Hyewon Han and
• Jongwoo Son

Beilstein J. Org. Chem. 2025, 21, 200–216, doi:10.3762/bjoc.21.12

• dioxazolone 7. Subsequently, nitrene insertion of INT-12 into the Cu–C bond, forms INT-13, which then undergoes isomerization and protodemetalation, followed by catalyst regeneration, as suggested by the DFT calculations. Finally, the nucleophilic addition of the amine to the electrophilic intermediate INT-15

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

• the product are accessible by adjusting the two distinct chiral catalysts. C–N Bond formation In 2018, Mei et al. developed the electrochemical C–H amination of arenes with amine electrophiles using copper catalysis, which provided a step-economical approach for the synthesis of aromatic amines by

• Figure 11. Initially, the Cu(II) catalyst 50 coordinates with substrate 47 and amine electrophile 48 to generate Cu(II) intermediate 51, which is then oxidized by the iodine radical to form Cu(III) complex 52. Cu(III) complex 52 undergoes electron transfer to produce radical cation intermediate 53

• . Subsequent intramolecular amine transfer to the radical cation intermediate 53, followed by ligand exchange, yields amination product 49 and Cu(I) species 55. Cu(II) catalyst 50 is regenerated by anodic oxidation, thereby completing the catalytic cycle. In 2019, Nicholls et al. reported a Cu-catalyzed

Cu(OTf)₂-catalyzed multicomponent reactions

• Sara Colombo,
• Camilla Loro,
• Egle M. Beccalli,
• Gianluigi Broggini and
• Marta Papis

Beilstein J. Org. Chem. 2025, 21, 122–145, doi:10.3762/bjoc.21.7

• counteranion. The use of a carbamate among the substrates instead of the amine allowed the synthesis of propargylcarbamates 11. This reaction, effective only for the aromatic aldehydes, did not require other co-catalysts or ligands (Scheme 8) [21]. Three-component reactions of alkynes, alkyltrifluoroborates

• Pd-catalyzed cross-coupling reactions, allowing the formation of C–C and C–N bonds in the o-position of the aryl chalcogen compounds. α-Aminophosphonates 14 were the result of a one-pot condensation of an aldehyde, a primary amine and phosphite P(OMe)3 with copper triflate acting as Lewis acid

• reaction between the anhydride and the amine suggested the subsequent reaction with the ketone to give an imine intermediate XXIV. This latter can undergo intramolecular nucleophilic attack affording the quinazolinone derivative 26 (Scheme 20) [37]. Polysubstituted pyrroles 27 were obtained in a cascade

Recent advances in organocatalytic atroposelective reactions

• Henrich Szabados and
• Radovan Šebesta

Beilstein J. Org. Chem. 2025, 21, 55–121, doi:10.3762/bjoc.21.6

Hot shape transformation: the role of PSar dehydration in stomatocyte morphogenesis

• Remi Peters,
• Levy A. Charleston,
• Karinan van Eck,
• Teun van Berlo and
• Daniela A. Wilson

Beilstein J. Org. Chem. 2025, 21, 47–54, doi:10.3762/bjoc.21.5

• glutamate) (PBLG) as the hydrophobic block, which was done to prevent ending on a primary amine in the final product which could disrupt self-assembly due to its ionizable nature. Subsequently, PBLG served as a macroinitiator for the polymerization of sarcosine NCA, yielding the final polymer with high

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

• ]. One of the most studied and inexpensive routes to synthesize substituted phenethylamines focuses on the reduction of their α,β-unsaturated nitroalkene analogue (β-nitrostyrene), where both the double bond and the nitro group need to be reduced to deliver the corresponding primary amine. Their

• precipitated under stirring with an excess of 2 N HCl in diethyl ether solution and the vessel was cooled to 5 °C. The solid was filtered, washed with cold diethyl ether, and dried under reduced pressure as the amine hydrochloride salt. (II) An excess of 4 N HCl in dioxane solution was added and the filtrate

• was stirred for 30 minutes. The residue was concentrated under reduced pressure, suspended in dry cold acetone, and stirred vigorously for 1 hour. The suspension was filtered and washed with a minimum amount of cold acetone to deliver the product as hydrochloride salt. 2-Phenylethan-1-amine

Reactivity of hypervalent iodine(III) reagents bearing a benzylamine with sulfenate salts

• Beatriz Dedeiras,
• Catarina S. Caldeira,
• José C. Cunha,
• Clara S. B. Gomes and
• M. Manuel B. Marques

Beilstein J. Org. Chem. 2024, 20, 3281–3289, doi:10.3762/bjoc.20.272

• benziodoxol(on)es can be found in the literature, including reagents featuring cyclic aliphatic amine moieties (III) [15], phthalimidates (IV) [16], and carbazoles (VII) [19]. Minakata and co-workers proposed an innovative approach for transferring imine groups using iodane-containing (diarylmethylene)amino

• groups (V), which proved to be useful in the transfer of imine radicals [17]. Bolm et al. contributed also to this topic by introducing a sulfoximidoyl-containing benziodoxolone (VI) [18]. Recently, our group disclosed the first HIRs bearing a primary amine moiety, the benzylamine benziodoxolone reagent

• benziodoxolone was generated in situ, via a reaction of chlorobenziodoxolone with sulfinate salts, followed by the addition of amines or hydrazines, respectively. On the follow-up on our research, we envisaged to extend the diversity of BBX reagents as electrophilic amine reagents and investigated their

Non-covalent organocatalyzed enantioselective cyclization reactions of α,β-unsaturated imines

• Sergio Torres-Oya and
• Mercedes Zurro

Beilstein J. Org. Chem. 2024, 20, 3221–3255, doi:10.3762/bjoc.20.268

• -raising activation (amine-based catalysis and N-heterocyclic carbenes), and iii) LUMO-lowering and HOMO-raising activation (bifunctional thioureas and squaramides). Due to the ubiquitous nature of non-covalent interactions in organic systems, they can play a decisive role in asymmetric transformations [15

• Michael addition product was obtained with low diastereoselectivity. The mechanism is described in Scheme 4: the bifunctional squaramide activates the azadiene through hydrogen bonding while the malononitrile is deprotonated by the tertiary amine present in the backbone of the catalyst, establishing

• hydrogen bonding with the protonated tertiary amine. Then, a Michael addition of malononitrile to the azadiene takes place to obtain exclusively the (S)-intermediate A. Subsequently an intramolecular nucleophilic addition of the nitrile leads to the intermediate B, which undergoes tautomerization to

Discovery of ianthelliformisamines D–G from the sponge Suberea ianthelliformis and the total synthesis of ianthelliformisamine D

• Sasha Hayes,
• Yaoying Lu,
• Bernd H. A. Rehm and
• Rohan A. Davis

Beilstein J. Org. Chem. 2024, 20, 3205–3214, doi:10.3762/bjoc.20.266

• commercially available primary amine, 1-(3-aminopropyl)pyrrolidin-2-one completed the total synthesis of the natural product in an overall yield of 1.5%. The NMR data comparison of the natural product and our synthetic compound was essentially identical. Due to our interest in the identification of potential

• –activity relationship data, leading to speculation over the moieties responsible for their antibiotic effects. A reduction in the number of amines in the polymeric chain and the absence of a primary amine was noted to decrease bioactivity by Xu et al. [7]. Research reported by Khan et al. in 2014 [9] also

Synthesis of 2H-azirine-2,2-dicarboxylic acids and their derivatives

• Anastasiya V. Agafonova,
• Mikhail S. Novikov and
• Alexander F. Khlebnikov

Beilstein J. Org. Chem. 2024, 20, 3191–3197, doi:10.3762/bjoc.20.264

• reaction conditions for the preparation of amides from azirine-2-carbonyl chlorides [27] are not suitable for obtaining bis-amides from azirine-2,2-dicarbonyl dichlorides. In order to obtain a maximum yield, it is better in this case, to carry out the reaction with 2 equiv of the amine in the presence of 4

• equiv of Cs2CO3 to trap hydrogen chloride. Additionally, the workup procedure, in which the product is isolated by filtration through celite after reaction with the amine, often allows one to obtain higher yields than an aqueous treatment of the reaction mixture. A number of amides 10a–h were obtained

• -2,2-dicarboxylic acids 6. Transformations of 3-(tert-butyl)-5-chloroisoxazole-4-carbonyl chloride (1j). Synthesis of amides 10. aFiltration through celite after reaction with amine (without aqueous workup). bWork up with H2O. Synthesis of esters 11. Synthesis of dicarbonyl azide 12. Synthesis of 5

Synthesis of extended fluorinated tripeptides based on the tetrahydropyridazine scaffold

• Thierry Milcent,
• Pascal Retailleau,
• Benoit Crousse and
• Sandrine Ongeri

Beilstein J. Org. Chem. 2024, 20, 3174–3181, doi:10.3762/bjoc.20.262

• has become an essential structural motif in medicinal chemistry due to its hydrogen-bond donor capacity, its lipophilic character, and as a bioisostere for alcohol, thiol, or amine groups [16][17][18][19]. Thus, the contribution of fluorinated compounds to pharmaceuticals has been crucial for more

Multicomponent reactions driving the discovery and optimization of agents targeting central nervous system pathologies

• Lucía Campos-Prieto,
• Aitor García-Rey,
• Eddy Sotelo and
• Ana Mallo-Abreu

Beilstein J. Org. Chem. 2024, 20, 3151–3173, doi:10.3762/bjoc.20.261

• other approaches such as visible light, microwaves, heterogeneous catalysis, and ultrasound [12][13][14][15]. Due to its versatility, one of the most prevalent of these MCRs is the Ugi reaction [16]. This reaction generally combines an isocyanide with an acid, an amine, and an aldehyde or ketone to

• development as a therapeutic agent for AD. Petasis reaction: Continuing in the context of the development of MTDLs, in 2023 Madhav et al. [40] reported the synthesis of pyrazine-based MTDLs using the Petasis reaction, which involves a secondary amine, a suitable aldehyde, and a substituted boronic acid in the

• intramolecular SNAr reactions. Ugi-4CR/deprotection/cyclization (UDC) strategy: In the UDC approach a protected amine and an electrophilic functional group like esters or ketones are used. Convertible isocyanides can also be employed. Once the Ugi reaction is completed, the protecting group is removed, and the

Advances in the use of metal-free tetrapyrrolic macrocycles as catalysts

• Mandeep K. Chahal

Beilstein J. Org. Chem. 2024, 20, 3085–3112, doi:10.3762/bjoc.20.257

• one remaining –NH group is catalytically active while both tri- and tetraalkylated analogues 40 and 41, without an –NH unit, are not. Further, the authors performed 1H NMR experiments with a different substrate:macrocycle ratio and suggested a bifunctional reaction mechanism involving both inner amine

• ones with secondary amine side arm (48d, 48g, h) were catalytically active for Michael additions, providing 60–71% yields (Table 3), whereas tetraalkylated analogues (49a–g) and dialkylated OxPs without a secondary amine side arm (48a–c, 48e and 48i) were not. Based on these results, the authors have

• secondary amine 57. They have hypothesized that the organocatalytic activity of the aggregates is based on two types of interactions, i.e., electrostatic interactions of α,β-unsaturated iminium cations derived from cinnamaldehyde and the cyclic secondary amine with anionic sulfonate groups and π–π

Synthesis of the 1,5-disubstituted tetrazole-methanesulfonylindole hybrid system via high-order multicomponent reaction

• Cesia M. Aguilar-Morales,
• América A. Frías-López,
• Nadia V. Emilio-Velázquez,
• Alejandro Islas-Jácome,
• Angelica Judith Granados-López,
• Jorge Gustavo Araujo-Huitrado,
• Yamilé López-Hernández,
• Hiram Hernández-López,
• Luis Chacón-García,
• Jesús Adrián López and
• Carlos J. Cortés-García

Beilstein J. Org. Chem. 2024, 20, 3077–3084, doi:10.3762/bjoc.20.256

• trifluoroethanol as the solvent and at room temperature [23][24][25][26]. In the initial reaction, propargylamine served as a bifunctional reagent, with the primary amine group participating in the first step and the terminal alkyne promoting the subsequent heteroannulation. (Scheme 2). As observed in our previous

Enantioselective regiospecific addition of propargyltrichlorosilane to aldehydes catalyzed by biisoquinoline N,N’-dioxide

• Noble Brako,
• Sreerag Moorkkannur Narayanan,
• Amber Burns,
• Layla Auter,
• Valentino Cesiliano,
• Rajeev Prabhakar and
• Norito Takenaka

Beilstein J. Org. Chem. 2024, 20, 3069–3076, doi:10.3762/bjoc.20.255

• quenching with aqueous NaOH or NaHCO3 solutions. Results and Discussion Our group recently reported that N,N-diisopropylethylamine required for the synthesis of propargyltrichlorosilane isomerized it to allenyltrichlorosilane in the absence of solvents, and that removal of the amine before the distillation

• prevent a direct Si–N interaction. From Rprop, the amine group of N,N-diisopropylethylamine abstracts the H1 proton with a barrier of 14.2 kcal/mol to form an intermediate (IN1). The intermediate IN1 is unstable (endergonic by 14.0 kcal/mol) and will immediately stabilize to another intermediate (IN2

Chemical structure metagenomics of microbial natural products: surveying nonribosomal peptides and beyond

• Thomas Ma and
• John Chu

Beilstein J. Org. Chem. 2024, 20, 3050–3060, doi:10.3762/bjoc.20.253

• to fully understand the determinant(s) of NRP topology. There are many ways to classify NRPs when topology and chemical structural features are considered simultaneously. For example, a macrocycle may be a lactam or a lactone depending on whether the internal nucleophile is an amine or an alcohol

Tailored charge-neutral self-assembled L₂Zn₂ container for taming oxalate

• David Ocklenburg and
• David Van Craen

Beilstein J. Org. Chem. 2024, 20, 3007–3015, doi:10.3762/bjoc.20.250

• ligand resulted in no clean formation of a charge-neutral metallocontainer with zinc(II) acetate. We believe that the modification with benzoyl chloride does not only alter the solubility but also shields the secondary amine which might act as additional coordination site. Binding of monocarboxylate

Advances in radical peroxidation with hydroperoxides

• Oleg V. Bityukov,
• Pavel Yu. Serdyuchenko,
• Andrey S. Kirillov,
• Gennady I. Nikishin,
• Vera A. Vil’ and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2024, 20, 2959–3006, doi:10.3762/bjoc.20.249

• proposed mechanism of amine 72 peroxidation is the oxidation of Cu(I) with TBHP, resulting in the formation of tert-butoxy radical A, which abstracts the hydrogen atom from substrate 72 to form the C-centered radical B. The generated Cu(II) oxidizes TBHP to form tert-butylperoxy radical C, which recombines

Recent advances in transition-metal-free arylation reactions involving hypervalent iodine salts

• Ritu Mamgain,
• Kokila Sakthivel and
• Fateh V. Singh

Beilstein J. Org. Chem. 2024, 20, 2891–2920, doi:10.3762/bjoc.20.243

• group with a less hindered portion is observed. The mechanism revealed the reaction undergoes the homolytic cleavage of the diaryliodonium salt to produce an iodoaryl radical cation, which further reacts with the amine to acquire the corresponding diaryl amines. Moreover, a similar reaction tried with a

• diaryliodonium salts 40 (Scheme 18) [69], which however, does not produce the diarylated compounds. The intramolecular aryl migration from the iodine to the nitrogen leads to a quaternary ammonium ion intermediate A. Consequently, a nucleophilic ring opening of cyclic amine in 42 occurred via cleavage of the

N-Glycosides of indigo, indirubin, and isoindigo: blue, red, and yellow sugars and their cancerostatic activity

• Peter Langer

Beilstein J. Org. Chem. 2024, 20, 2840–2869, doi:10.3762/bjoc.20.240

• -glycoside 11a (Scheme 7) [20]. Debenzylation gave product 11b which was transformed to akashin A (11c) by reduction of the azide to the amine in the presence of propane-1,3-dithiol and subsequent debenzoylation. Akashin A was transformed to akashins B and C by acetylation and reaction with diacetyl

• -mannose (14) afforded indigo-N-mannoside α-15a, albeit, in low yield (Scheme 11) [21]. Deacetylation afforded product α-15b. Indirubin-N-glycosides (red sugars) In contrast to indigo, indirubin is a non-symmetrical compound containing an amine- and an amide-type nitrogen atom. In our group, we developed a

• -glycosides containing the carbohydrate moiety located at the amine-type nitrogen atom (Scheme 18) [25]. For this purpose, we decided to react isatins with N-glycosylated indoxyls which were entirely unknown at that time. The reaction of ʟ-rhamnose α/β-4c with indoline afforded α/β-25a (β:α ≈ 4:1

Multicomponent synthesis of α-branched amines using organozinc reagents generated from alkyl bromides

• Baptiste Leroux,
• Alexis Beaufils,
• Federico Banchini,
• Olivier Jackowski,
• Alejandro Perez-Luna,
• Fabrice Chemla,
• Marc Presset and
• Erwan Le Gall

Beilstein J. Org. Chem. 2024, 20, 2834–2839, doi:10.3762/bjoc.20.239

• 16 h at 80 °C (Table 1, entry 2). However, its suitability in the multicomponent coupling with an amine and an aldehyde still had to be demonstrated as there was no precedent for such a Mannich multicomponent coupling involving nonstabilized organozinc halides using THF or 2-MeTHF as solvent. To our

• species 2 were collected using a syringe and allowed to react with an amine 3 and an aldehyde 4 under moderate heating (Scheme 2). The multicomponent couplings proceeded smoothly, with an acceptable yield of the α-branched amine being obtained after 3 h at 50 °C. A range of secondary amines as well as

• various aromatic aldehydes could be used in the multicomponent coupling. Interestingly, functionalized organozinc reagents gave the multicomponent coupling product, except for the cyanated organozinc compound 2d, which only provided traces of the expected α-branched amine. It can be noted that in sharp

Synthesis of tricarbonylated propargylamine and conversion to 2,5-disubstituted oxazole-4-carboxylates

• Kento Iwai,
• Akari Hikasa,
• Kotaro Yoshioka,
• Shinki Tani,
• Kazuto Umezu and
• Nagatoshi Nishiwaki

Beilstein J. Org. Chem. 2024, 20, 2827–2833, doi:10.3762/bjoc.20.238

• anhydride, the intermediately formed hemiacetal underwent acetylation, leading to N,O-acetals 1. In this method, an acid amide can be used as an amine masked with an acyl group. Subsequent elimination of acetic acid occurred to afford 2 in situ upon treatment with a base, enabling nucleophilic addition with

• nucleophiles to synthesize PCPAs, and their ring closures were also investigated. Results and Discussion NAI 2 can be generated by treating N,O-acetal 1 with a base, such as triethylamine. However, the addition of an amine was omitted because lithium acetylide functions both as nucleophile and base. When 1a

Investigation of a bimetallic terbium(III)/copper(II) chemosensor for the detection of aqueous hydrogen sulfide

• Parvathy Mini,
• Michael R. Grace,
• Genevieve H. Dennison and
• Kellie L. Tuck

Beilstein J. Org. Chem. 2024, 20, 2818–2826, doi:10.3762/bjoc.20.237

• , highly sensitive chemosensors via a facile synthetic route/method, we have explored three chelates for lanthanide ions (DO3A, 2,6-pyridinedicarboxylic acid and DO2A), resulting in complexes with different overall charges. Additionally we have explored two copper(II) binding groups (di(2-picolyl)amine and

Synthesis and antimycotic activity of new derivatives of imidazo[1,2-a]pyrimidines

• Dmitriy Yu. Vandyshev,
• Daria A. Mangusheva,
• Khidmet S. Shikhaliev,
• Kirill A. Scherbakov,
• Oleg N. Burov,
• Alexander D. Zagrebaev,
• Tatiana N. Khmelevskaya,
• Alexey S. Trenin and
• Fedor I. Zubkov

Beilstein J. Org. Chem. 2024, 20, 2806–2817, doi:10.3762/bjoc.20.236

• , it is worth mentioning the work of Li and co-workers (2011) [20], who described a single example of the formation of such structures by carrying out an organocatalytic domino aza-Michael–Mannich reaction between benzylidene-1H-imidazol-2-amine and cinnamaldehyde. Although the imidazo[1,2-a

Access to optically active tetrafluoroethylenated amines based on [1,3]-proton shift reaction

• Yuta Kabumoto,
• Eiichiro Yoshimoto,
• Bing Xiaohuan,
• Masato Morita,
• Motohiro Yasui,
• Shigeyuki Yamada and
• Tsutomu Konno

Beilstein J. Org. Chem. 2024, 20, 2776–2783, doi:10.3762/bjoc.20.233

• amides in moderate three-step yields. Keywords: amine; chirality transfer; [1,3]-proton shift reaction; tetrafluoroethylene fragment; Introduction A fluorine atom has quite peculiar chemical and physical properties compared to others, and hence changes in molecular properties resulting from the

• 22b could not be completely suppressed. The thus obtained [1,3]-proton shift product (S)-20b was subjected to 2 N HCl aq in Et2O for 2 h, and subsequently 2 N NaOH aq, affording the corresponding free amine (S)-17b. Then, treatment of the amine with CbzCl and pyridine in CH2Cl2 gave the corresponding

• good yield and a high asymmetric transfer was achieved. As a result, it was found that various optically active amine derivatives could be obtained with high optical purity. Various applications of tetrafluoroethylenated molecules. Precedent synthetic approaches to optically active compounds possessing