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

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

• (Scheme 16) [33]. The reaction, which occurs with formation of C–C, C–N and C–O bonds, involves a nucleophilic addition of the activated alkyne XIV to the in situ-generated iminium ion XV, followed by cyclization to form a quinoxalin-2-one intermediate XVI. A subsequent 5-endo-dig cyclization involving

• corresponding saturated compounds. Subsequent nucleophilic addition of the cyclic vinyl ether to the iminium salt generates an intermediate XXI susceptible of intramolecular electrophilic attack to give a tricyclic structure XXII. The final deprotonation provides the desired product 24. The multicomponent

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

• intermediate Int-9. As the assumed rate-determining step the intramolecular nucleophilic addition takes place, followed by further cyclization and finally, release of the organocatalyst to form the axially chiral product 9. Various aryl-substituted indolines 9 were obtained in good yields and high enantiomeric

• enantioselectivity during the nucleophilic addition, and the subsequent aromatization completes central-to-axial chirality conversion delivering products 68. Dynamic kinetic resolution of naphthylindoles 69 was performed by reaction with bulky electrophiles such as azodicarboxylates 70 or o-hydroxybenzyl alcohols 72

• . The proposed reaction pathway follows hydrogen bonding with alkynylnaphthylamine and later nucleophilic addition of the allene intermediate. The synthesis on the preparative scale provided product 183 with almost no deterioration in yield or enantioselectivity (90%, 91% ee). This product could then be

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

• 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

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

• mainly include: nucleophilic addition or nucleophilic substitution with H2O2 or ROOH [17][18], autoxidation with O2, pericyclic reactions of unsaturated bonds with O3 or O2, and metal-catalyzed peroxidation (Isayama–Mukaiyama hydrosilylperoxidation [19][20], for example) [21][22][23]. As the topic is

• to generate the iodoperoxidate intermediate C. Finally, nucleophilic addition of anion of carboxylic acid to intermediate C generates the desired product 216. Based on the iodination/peroxidation strategy the approach to α-hydroxy-β-peroxyethylarenes 219 and α-alkoxy-β-peroxyethylarenes 218 from

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

• ] because of their easily modifiable dipeptide frameworks. Several methods exist for accessing PCPAs, such as the amination of 1-halo-1-alkynes [16][17], tandem reactions of α-imino esters with nucleophiles and electrophiles [18], and the nucleophilic addition of an acetylide to α-carbonylated N-acylimines

• derivative has been employed (Scheme 1) [13][14]. Recently, we have demonstrated that the central carbonyl group of DEMO is highly electrophilic, facilitating the nucleophilic addition of less reactive reagents such as acid amides [23][24][25][26]. When the reaction was conducted in the presence of acetic

• 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

Base-promoted cascade recyclization of allomaltol derivatives containing an amide fragment into substituted 3-(1-hydroxyethylidene)tetronic acids

• Andrey N. Komogortsev,
• Constantine V. Milyutin and
• Boris V. Lichitsky

Beilstein J. Org. Chem. 2024, 20, 2585–2591, doi:10.3762/bjoc.20.217

• was isolated in unchanged form. It should be mentioned that the key step of the studied recyclization is an intramolecular nucleophilic addition of a nitrogen atom at the double bond of the pyranone ring. Comparing the chemical properties of the considered amides and hydrazides it can be assumed that

Photoredox-catalyzed intramolecular nucleophilic amidation of alkenes with β-lactams

• Valentina Giraldi,
• Giandomenico Magagnano,
• Daria Giacomini,
• Pier Giorgio Cozzi and
• Andrea Gualandi

Beilstein J. Org. Chem. 2024, 20, 2461–2468, doi:10.3762/bjoc.20.210

• , Via Gobetti 85, 40129 Bologna, Italy 10.3762/bjoc.20.210 Abstract The direct nucleophilic addition of amides to unfunctionalized alkenes via photoredox catalysis represents a facile approach towards functionalized alkylamides. Unfortunately, the scarce nucleophilicity of amides and competitive side

• reactions limit the utility of this approach. Herein, we report an intramolecular photoredox cyclization of alkenes with β-lactams in the presence of an acridinium photocatalyst. The approach uses an intramolecular nucleophilic addition of the β-lactam nitrogen atom to the radical cation photogenerated in

• functionalization of amides with alkenes under photoredox conditions. Another viable approach for amide functionalization through photoredox catalysis involves the nucleophilic addition, in the presence of base, of an amide to a radical cation obtained by oxidation of an unfunctionalized alkene moiety (Figure 1A

Facile preparation of fluorine-containing 2,3-epoxypropanoates and their epoxy ring-opening reactions with various nucleophiles

• Yutaro Miyashita,
• Sae Someya,
• Tomoko Kawasaki-Takasuka,
• Tomohiro Agou and
• Takashi Yamazaki

Beilstein J. Org. Chem. 2024, 20, 2421–2433, doi:10.3762/bjoc.20.206

• anionic species from, for example, malonate. One reason could be because of the formation of the less stable alkoxide by the progress of the nucleophilic addition. If this is really the case, the presence of the strongly electron-withdrawing fluorine-containing groups in our instance should nicely affect

Asymmetric organocatalytic synthesis of chiral homoallylic amines

• Nikolay S. Kondratyev and
• Andrei V. Malkov

Beilstein J. Org. Chem. 2024, 20, 2349–2377, doi:10.3762/bjoc.20.201

• highly enantioselective nucleophilic addition of primary (10), secondary, and even tertiary allylboronates, as well as allenylboronates to a broad set of imines, bearing the N-phosphinoyl group. The new approach allowed the activation of both the substrate and the reagent using aminophenol organocatalyst

• -Fmoc-aryl- and -alkylimines, catalysed by a chiral disulfonimide 45 (Scheme 10). Since allyltrimethylsilane (46) belongs to the type 2 allylation reagents [33], the nucleophilic addition proceeds via an open transition state (Figure 1). Two possible mechanistic pathways were proposed, where the Fmoc

• enantioselective allylation of imines was described by Ryu’s group as a part of a wider asymmetric nucleophilic addition methodology [37]. The method is based on the use of 20 mol % of sterically hindered chiral oxazaborolidinium ion (COBI) 63, that can be readily prepared from a relatively inexpensive

Stereoselective mechanochemical synthesis of thiomalonate Michael adducts via iminium catalysis by chiral primary amines

• Michał Błauciak,
• Dominika Andrzejczyk,
• Błażej Dziuk and
• Rafał Kowalczyk

Beilstein J. Org. Chem. 2024, 20, 2313–2322, doi:10.3762/bjoc.20.198

• catalysis with hydrogen bonding units has been essential for achieving high reactivity and enantioselectivities [21][22]. Additionally, the reactivity of the nucleophilic addition is influenced by substitutions near the electron-poor double bond. This approach requires 30 mol % of catalyst and a reaction

• efficiency. Motivated by our curiosity surrounding the reactivity of alicyclic enones with bis-thiomalonates, we embarked on a study to evaluate a chosen catalytic system's efficacy under both standard conditions and mechanochemical milling. We aimed to facilitate the nucleophilic addition of 1–4 to 4

Catalysing (organo-)catalysis: Trends in the application of machine learning to enantioselective organocatalysis

• Stefan P. Schmid,
• Leon Schlosser,
• Frank Glorius and
• Kjell Jorner

Beilstein J. Org. Chem. 2024, 20, 2280–2304, doi:10.3762/bjoc.20.196

Selective hydrolysis of α-oxo ketene N,S-acetals in water: switchable aqueous synthesis of β-keto thioesters and β-keto amides

• Haifeng Yu,
• Wanting Zhang,
• Xuejing Cui,
• Zida Liu,
• Xifu Zhang and
• Xiaobo Zhao

Beilstein J. Org. Chem. 2024, 20, 2225–2233, doi:10.3762/bjoc.20.190

• thioesters and acyl chlorides (Scheme 1a, path 7) [30]. For β-keto amides, they could be efficiently synthesized from the nucleophilic substitution reactions of amines with β-keto acids (Scheme 1b, path 1) [31][32][33], β-keto esters (Scheme 1b, path 2) [34] and the nucleophilic addition reactions of amines

Heterocycle-guided synthesis of m-hetarylanilines via three-component benzannulation

• Andrey R. Galeev,
• Maksim V. Dmitriev,
• Alexander S. Novikov and
• Andrey N. Maslivets

Beilstein J. Org. Chem. 2024, 20, 2208–2216, doi:10.3762/bjoc.20.188

• of acetone and amines 2 leads to the formation of acetone imine/enamine (reaction 1, Scheme 6). Nucleophilic addition of an enamine to the most electron-deficient carbonyl group (C1=O, adjacent to the EWG) of the 1,3-diketones 1 gives the acyclic carbinol I (reaction 2, Scheme 6), followed by the

Multicomponent syntheses of pyrazoles via (3 + 2)-cyclocondensation and (3 + 2)-cycloaddition key steps

• Ignaz Betcke,
• Alissa C. Götzinger,
• Maryna M. Kornet and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2024, 20, 2024–2077, doi:10.3762/bjoc.20.178

• , product 17a shows cytotoxic activity against Hep G2 hepatocellular carcinoma and MCF-7 breast carcinoma cell lines. The synthesis of 3,5-bis(arylamino)pyrazoles 21 involves the preparation of bisarylthioamides 22 via nucleophilic addition and double retro-Claisen condensation of isothiocyanates 19 and

• -hydroxypyrazoles 143 and not tautomeric 3-pyrazolones. Alternative access to alkynones can be achieved by nucleophilic addition of lithiated alkynes to N-substituted phthalimides 145, followed by ring opening to give, upon the addition of water, the corresponding 3-hydroxyindolines. These intermediates are in

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

• undergo deprotonation delivering the oxadiazole 24a. Alternatively, from 23b (R2 ≠ H), nucleophilic addition of methanol to oxycarbenium 26b yielded the oxadiazoline 24b (Scheme 6) [41][42]. In 2020, Lei, Zhang and Gao et al. described the electrooxidative cyclization of in situ-generated α-keto acid

• the electrolysis was a four-electron oxidative process. Based on this study, the authors proposed the initial anodic oxidation of hydrazone 44 through the loss of two electrons and one proton to form cation 47. Subsequent nucleophilic addition of the azaarene led to new highly acidic cationic species

• species to be oxidized, initial SET anodic oxidation of the hydrazone furnishes the highly electrophilic radical cation species D, which undergo nucleophilic addition of the second partner and deprotonation to produce hydrazinyl radical F (route a). Alternatively, if the partner possesses a lower

The Groebke–Blackburn–Bienaymé reaction in its maturity: innovation and improvements since its 21st birthday (2019–2023)

• Cristina Martini,
• Muhammad Idham Darussalam Mardjan and
• Andrea Basso

Beilstein J. Org. Chem. 2024, 20, 1839–1879, doi:10.3762/bjoc.20.162

• intramolecular nucleophilic addition of the secondary amines to the internal alkyne was expected to occur, forming a new pyrrole ring in 93 through a 5-endo-dig cyclization. Unexpectedly, they observed the generation of 95 with a new pyridine ring. The authors proposed that the benzylamine unit of 92 was

Syntheses and medicinal chemistry of spiro heterocyclic steroids

• Laura L. Romero-Hernández,
• Ana Isabel Ahuja-Casarín,
• Penélope Merino-Montiel,
• Sara Montiel-Smith,
• José Luis Vega-Báez and
• Jesús Sandoval-Ramírez

Beilstein J. Org. Chem. 2024, 20, 1713–1745, doi:10.3762/bjoc.20.152

• -lactone motif on an estradiol backbone [17]. Beginning with the 7α-alkanamidoestrone derivative 17, a nucleophilic addition by the anion of the THP propargyl ether occurred stereoselectively and provided the alkyne 18 in a 75% yield. Afterwards, the catalytic hydrogenation of the alkyne with a 1:1 mixture

Synthesis of 2-benzyl N-substituted anilines via imine condensation–isoaromatization of (E)-2-arylidene-3-cyclohexenones and primary amines

• Lu Li,
• Na Li,
• Xiao-Tian Mo,
• Ming-Wei Yuan,
• Lin Jiang and
• Ming-Long Yuan

Beilstein J. Org. Chem. 2024, 20, 1468–1475, doi:10.3762/bjoc.20.130

• -cyclohexenones with nucleophilic nitrogen sources like ammonia, amines and hydrazine [14]. The reactions were regarded as via simple nucleophilic addition along with Pd-catalyzed dehydrogenative aromatization in these elegant works (Scheme 1, (1)). The Semmler–Wolff reaction is often implemented in the synthesis

Rapid construction of tricyclic tetrahydrocyclopenta[4,5]pyrrolo[2,3-b]pyridine via isocyanide-based multicomponent reaction

• Xiu-Yu Chen,
• Ying Han,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2024, 20, 1436–1443, doi:10.3762/bjoc.20.126

• polycyclic compounds. At first, the nucleophilic addition of alkyl isocyanide to dialkyl but-2-ynedioate afforded the expected Huisgen’s 1,4-dipolar intermediate A. Secondly, the sequential addition of the Huisgen’s 1,4-dipole A to the second molecular dialkyl but-2-ynedioate resulted in a 1,5-dipolar

• -deficient alkynes [59][60][61][62][63]. The in situ generated cyclic intermediate C has a resonance hybrid C’. Then, the further nucleophilic addition of the electron-rich enamino unit to 5-(alkylimino)cyclopenta-1,3-diene intermediate C gave intermediate D. At last, the coupling of the iminium cation with

Challenge N- versus O-six-membered annulation: FeCl₃-catalyzed synthesis of heterocyclic N,O-aminals

• Giacomo Mari,
• Lucia De Crescentini,
• Gianfranco Favi,
• Fabio Mantellini,
• Diego Olivieri and
• Stefania Santeusanio

Beilstein J. Org. Chem. 2024, 20, 1412–1420, doi:10.3762/bjoc.20.123

• . Based on our previous findings [17][18][19], the initial nucleophilic addition of α-aminoacetals 2a,b as nitrogen source to the activated heterodiene system of 4-methoxycarbonyl-DDs 1a–f in dichloromethane (DCM) or ethanol (EtOH) at room temperature affords N-aminohydrazone derivatives I (Scheme 2

• , promoting, via hydrazone–enamine tautomerization [17][24][25], the nucleophilic addition which concludes with the construction of the heterocyclic N,O-aminal 5 through the intramolecular N–C bond formation. The FeCl3 can also interact with the newly formed N,O-aminals 5, giving rise to the second parallel

Hypervalent iodine-catalyzed amide and alkene coupling enabled by lithium salt activation

• Akanksha Chhikara,
• Fan Wu,
• Navdeep Kaur,
• Prabagar Baskaran,
• Alex M. Nguyen,
• Zhichang Yin,
• Anthony H. Pham and
• Wei Li

Beilstein J. Org. Chem. 2024, 20, 1405–1411, doi:10.3762/bjoc.20.122

• positive charge was likely built up on the olefin prior to the nucleophilic addition. On the other hand, the electronic nature of the para-substituted benzamides had little impact on the overall reaction rate as both electron-rich and electron-deficient benzamides proceeded with similar kinetic profiles

(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

• substrate. Employing Lewis acid catalysis Deng and co-workers reported an alternative pathway to indole-derived BCHs. Polysubstituted BCHs were accessed by nucleophilic addition of the indole to the activated bicyclobutane followed by a Mannich cyclisation [81]. The synthesis of wide variety of tri- and

SOMOphilic alkyne vs radical-polar crossover approaches: The full story of the azido-alkynylation of alkenes

• Julien Borrel and
• Jerome Waser

Beilstein J. Org. Chem. 2024, 20, 701–713, doi:10.3762/bjoc.20.64

• -2. Finally, nucleophilic addition of the alkynyl-trifluoroborate onto the benzylic carbocation would afford homopropargylic azide 4 [45]. Conclusion In summary, an azido-alkynylation of styrenes to access homopropargylic azides was developed. The reaction was initially investigated using EBX

Palladium-catalyzed three-component radical-polar crossover carboamination of 1,3-dienes or allenes with diazo esters and amines

• Geng-Xin Liu,
• Xiao-Ting Jie,
• Ge-Jun Niu,
• Li-Sheng Yang,
• Xing-Lin Li,
• Jian Luo and
• Wen-Hao Hu

Beilstein J. Org. Chem. 2024, 20, 661–671, doi:10.3762/bjoc.20.59

• alkene followed by a nucleophilic addition, is unknown (Scheme 1b, bottom). The radical-polar crossover strategy has been steadily emerging in synthetic organic chemistry during the last few years [43][44][45][46]. This strategy allows complex chemicals to be assembled with high step economy that would

• 7 and 8 were produced in high yields through LiAlH4 conditions or nucleophilic addition of methylmagnesium bromide. Moreover, product 4a could be easily transformed to unsaturated ε-amino amide 9 in total 76% yield. Likewise, Weinreb amide 10 was produced and further transformed into ketone 11 in 84