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

• bisimidazolines are efficient chiral ligands in metal-catalyzed asymmetric organic transformations. Chiral cyclohexane-linked bisimidazolines were prepared from optically active cyclohexane-1,2-dicarboxylic acid and 1,2-diphenylethane-1,2-diamines via the monosulfonylation of 1,2-diphenylethane-1,2-diamines

• bisoxazolines [1][2][3][4][5][6][7][8][9] and bisimidazolines [10][11][12][13][14][15] are efficient chiral ligands and have been widely applied in various metal-catalyzed asymmetric organic transformations. Various chiral bisoxazoline ligands have been prepared from diacids and enantiopure vicinal amino

• alcohols and utilized in different metal-catalyzed asymmetric organic reactions [1][2][3][4][5][6][7][8][9]. In comparison with bisoxazoline ligands, relatively less attention has been paid to bisimidazoline ligands [10][11][12][13][14][15]. Some well investigated bisimidazoline ligands are pyridine-linked

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

• ; single crystals; thiones; Introduction In the past several years, C–N atropisomers (C–N axially chiral compounds) owing to the rotational restriction around a C–N single bond have received great attention as new target molecules for catalytic asymmetric reactions. Highly enantioselective syntheses of

• chemistry but also medicinal chemistry [10][11][12][13]. For example, 3-(2-bromophenyl)-2-methylquinazolin-4-one (I), which has a high rotational barrier about the N3–Ar bond, is known as mebroqualone possessing GABA agonist activity (Figure 1) [14][15]. Our group has been exploring asymmetric synthesis of

• C–N atropisomers and their structural properties for over 25 years [16][17]. As a part of the C–N atropisomeric chemistry, we succeeded in the asymmetric synthesis of mebroqualone (I) and the thione analogue II [18][19]. In the course of this study, it was found that intermolecular association 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

• conditions compatible with the double bond and acetal functions. In this work, we present Torii-type electrosynthesis of ester 3d (PG = Alloc) and its transformation to the enantioenriched vinyloxazoline building block 6, which can be used for the asymmetric synthesis of complex molecules [19][20][21][22][23

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

• Jia-Yu Liao College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, 310058, China 10.3762/bjoc.21.129 Abstract Beyond the conventional carbon-centered chirality, catalytic asymmetric transformations of isocyanides have recently emerged as a powerful strategy for the efficient synthesis

• attention due to its broad applications in various fields, including but not limited to drug discovery, asymmetric catalysis, and materials science (Figure 1b). Consequently, the development of efficient and stereoselective methods for assembling such scaffolds with respect to structural diversity has

• ], insertion reactions [16][17][18], cycloaddition reactions (e.g., [4 + 1], [3 + 2]) [19][20], and others [21][22][23]. Particularly, isocyanides have been widely exploited toward the preparation of centrally chiral structures through transition-metal-catalyzed or organocatalytic asymmetric reactions [24][25

Formal synthesis of a selective estrogen receptor modulator with tetrahydrofluorenone structure using [3 + 2 + 1] cycloaddition of yne-vinylcyclopropanes and CO

• Jing Zhang,
• Guanyu Zhang,
• Hongxi Bai and
• Zhi-Xiang Yu

Beilstein J. Org. Chem. 2025, 21, 1639–1644, doi:10.3762/bjoc.21.127

• asymmetric Lu [3 + 2] cycloaddition reaction [20][21] between indanone and allenyl ketone. Then hydrogenation and Robinson annulation delivered the core of the target molecule. Some other excellent synthetic routes for tetrahydrofluorenone derivates have been developed [12][13][14][15][16][17][18][19] but

Thermodynamic equilibrium between locally excited and charge transfer states in perylene–phenothiazine dyads

• Issei Fukunaga,
• Shunsuke Kobashi,
• Yuki Nagai,
• Hiroki Horita,
• Hiromitsu Maeda and
• Yoichi Kobayashi

Beilstein J. Org. Chem. 2025, 21, 1577–1586, doi:10.3762/bjoc.21.121

• absorption spectra and dynamics observed were generally similar to those of Pe–PTZ(TPA)2 (Supporting Information File 1, Figure S29c). However, the broad band between 700–800 nm is split into two peaks at 720 and 790 nm, likely due to asymmetric substitution of a single TPA group. The time constants of

• . Conversely, the deceleration of the early component (6.2 ps vs 2.4 ps for PTZ(TPA)2), likely associated with solvent reorientation, may be explained by the larger dipole rearrangement induced by excitation in this asymmetric molecular framework, which in turn requires more time for the reorganization of the

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

• community in that it elegantly reviews recent advances in allylation reactions of copper-catalyzed asymmetric allylic substitution reactions of chiral secondary alkylcopper species [5]. In summary, the contribution includes stereospecific transmetalations of organolithium and -boron compounds, copper

Advances in nitrogen-containing helicenes: synthesis, chiroptical properties, and optoelectronic applications

• Meng Qiu,
• Jing Du,
• Nai-Te Yao,
• Xin-Yue Wang and
• Han-Yuan Gong

Beilstein J. Org. Chem. 2025, 21, 1422–1453, doi:10.3762/bjoc.21.106

• applications in asymmetric catalysis [1][2], molecular recognition [3], and organic electronics [4][5]. In recent years, the incorporation of heteroatoms – particularly nitrogen – into the helicene backbone, giving rise to so-called "azahelicenes", has emerged as a powerful strategy to modulate electronic

• chiroptical and photophysical properties, highlighting the expanding potential of these molecules in chiral optoelectronics. Yorimitsu’s group developed a series of dihetero[8]helicenes through a systematic asymmetric synthesis. Among these, diaza[8]helicene 5 exhibited pronounced chiroptical activity, with

• , the team achieved the enantioselective synthesis of heterodehydrospiroenes on a gram scale using chiral vanadium(V) complexes – marking a significant advancement in asymmetric electrochemical catalysis. In a complementary study that same year, they reported a two-step electrochemical synthesis of a

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

• catalysis and proceed through a double addition mechanism. In 2011, Mikami et al. developed a catalytic asymmetric oxetane synthesis from silyl enol ethers 89 and trifluoropyruvate 90 using a chiral Cu(II) complex (Scheme 24) [67]. Besides excellent yields, they also observed very high cis/trans ratios and

• cases and worked very well for both aromatic and aliphatic amides, as well as sterically hindered oxetanes. The authors further proved the robustness of this reaction by preparing various bisoxazolines 189, compounds which are common bidentate ligands in asymmetric catalysis [99]. Over the years 2019

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

• -withdrawing or electron-donating substituents at the 6- (35a, 35b) and 7- (35c) positions, yielding pyrroloquinazolinones in 67–72% yields. Additionally, another heteroaromatic quinazolinone derivative 35g was obtained in satisfactory yield. In terms of malonates, asymmetric C–H radical precursors, including

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

• synthesis of polydeoxypropionate based on iridium-catalyzed asymmetric hydrogenation of α-substituted acrylic acid [40]. This method was subsequently applied to the synthesis of a promising vaccine candidate (+)-phthioceranic acid, as well as key intermediates for two natural products, ionomycin and

• borrelidin (C3–C11). The synthesis involved three main steps: (1) carboxymethylation using Meldrum’s acid, (2) alkenylation with Eschenmoser’s salt, and (3) asymmetric hydrogenation catalyzed by iridium complex (Ra)-50 or (Sa)-50. The authors began their investigation by performing the hydrogenation of α

• reacting it with Eschenmoser’s salt, followed by hydrolysis with lithium hydroxide. The resulting unsaturated acid 54, isolated in 92% yield, underwent asymmetric hydrogenation using both (Ra)-50 and (Sa)-50 catalysts. This step provided the respective compounds 55 and 56 in excellent high yield and

Salen–scandium(III) complex-catalyzed asymmetric (3 + 2) annulation of aziridines and aldehydes

• Linqiang Wang and
• Jiaxi Xu

Beilstein J. Org. Chem. 2025, 21, 1087–1094, doi:10.3762/bjoc.21.86

• moieties of biologically active compounds. A salen–scandium triflate complex-catalyzed asymmetric (3 + 2) annulation of dialkyl 1-sulfonylaziridine-2,2-dicarboxylates and aldehydes generated optically active functionalized oxazolidine derivatives in moderate to good yields and good to excellent

• [5] and the FDA-approved antibiotic linezolid [6] (Figure 1). Both chiral oxazolidines [7][8] and oxazolidinones [9][10] have been utilized as chiral auxiliary groups in many asymmetric organic transformations. Oxazolidine derivatives have been prepared mainly from condensation of vicinal amino

• derivatives were obtained under asymmetric catalysis with a Ni(II)–bisoxazoline complex [15] and a Nd(OTf)3/N,N'-dioxide/LiNTf2 delay catalytic system [16], respectively (Scheme 1b and c). However, further exploration for convenient asymmetric catalytic synthetic methods is still in demand because the former

Pd-Catalyzed asymmetric allylic amination with isatin using a P,olefin-type chiral ligand with C–N bond axial chirality

• Natsume Akimoto,
• Kaho Takaya,
• Yoshio Kasashima,
• Kohei Watanabe,
• Yasushi Yoshida and
• Takashi Mino

Beilstein J. Org. Chem. 2025, 21, 1018–1023, doi:10.3762/bjoc.21.83

• asymmetric allylic amination of allylic esters with isatin derivatives 11 as nucleophiles. The reaction proceeds efficiently, yielding the products (S)-13 with good-to-high enantioselectivity. A scale-up reaction was also successfully conducted at a 1 mmol scale. Additionally, when malononitrile was added to

• the resulting product (S)-13a in the presence of FeCl3 as the catalyst, the corresponding malononitrile derivative (S)-16 was obtained without any loss in optical purity. Keywords: asymmetric allylic amination; axial chirality; isatin; palladium catalysis; P,olefin-type chiral ligand; Introduction

• few studies have reported the use of isatin as a nucleophile in asymmetric reactions [9][10][11]. On the other hand, it has been revealed that compounds in which the carbon bonded to the nitrogen atom of newly constructed N-substituted isatin becomes a chiral center exhibit pharmacological properties

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

• -catalyzed asymmetric [2 + 3] annulation of tertiary enamides with enoldiazoacetates, enabling highly efficient total syntheses of Cephalotaxus alkaloids (Scheme 4) [27]. In their recent study, the homopiperonyl alcohol 26 was transformed into tricyclic enamide 28 in five steps in a decagram scale. As no

• cephalotaxine and cephalezomine H. Collective total syntheses of Cephalotaxus alkaloids. Asymmetric tandem cyclization/Pictet–Spengler reaction of tertiary enamides. Tandem cyclization/Pictet–Spengler reaction for the synthesis of chiral tetracyclic compounds. Total synthesis of (−)-cephalocyclidin A. Funding

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

• represents a highly challenging direct C(sp3)–H asymmetric amination. Mechanistic insights: When using a bulky, electron-rich chiral bisphosphine ligand L6, the glycine ester substrate coordinates with the copper catalyst to form a key intermediate complex Int-26. The sterically hindered and electron-rich

• -controlled regio- and enantioselective hydroalkylation reaction, enabling the divergent synthesis of chiral C2- and C3-alkylated pyrrolidines through desymmetrization of readily available 3-pyrrolines (Scheme 8) [31]. The cobalt catalytic system (CoBr₂ with modified bisoxazoline ligands) achieved asymmetric

• achieved selective synthesis of either enantiomer of a target product by controlling the reaction duration (Scheme 13) [42]. When performing the asymmetric intermolecular allylic amination of 6-hydroxyisoquinoline (49) with tert-butyl(1-phenylallyl)carbonate ((rac)-50) using an Ir catalyst derived from [Ir

4-(1-Methylamino)ethylidene-1,5-disubstituted pyrrolidine-2,3-diones: synthesis, anti-inflammatory effect and in silico approaches

• Nguyen Tran Nguyen,
• Vo Viet Dai,
• Luc Van Meervelt,
• Do Thi Thao and
• Nguyen Minh Thong

Beilstein J. Org. Chem. 2025, 21, 817–829, doi:10.3762/bjoc.21.65

• the weaker base, 4-methoxybenzylamine. X-ray study of 4-(1-methylamino)ethylidene-1,5-diphenylpyrrolidine-2,3-dione (5a) Compound 5a crystallizes in the triclinic space group P−1, with one molecule in the asymmetric unit (Figure 2). The pyrrolidine ring is planar (r.m.s. deviation = 0.004 Å) and forms

New advances in asymmetric organocatalysis II

• Radovan Šebesta

Beilstein J. Org. Chem. 2025, 21, 766–769, doi:10.3762/bjoc.21.60

• Radovan Sebesta Department of Organic Chemistry, Faculty of Natural Sciences, Comenius University in Bratislava, Mlynská dolina, Ilkovičova 6, 842 15 Bratislava, Slovakia 10.3762/bjoc.21.60 Keywords: asymmetric organocatalysis; covalent activation; noncovalent activation; Organocatalysis is

• organocatalysis. Even toward the end of the 20th century, there have been a few pioneering studies that should be counted as examples of asymmetric organocatalysis. The works of Jacobsen, Miller, Shi, and Denmark et al. marked the early sparks of interest in this type of chemistry based on catalysis by peptides

• prominent Hayashi–Jørgensen catalyst. This prolinol silyl ether was independently discovered by the respective Hayashi and Jørgensen research teams in 2005 [13][14]. Interestingly, the use of prolinol alkyl ethers for asymmetric Michael additions, although at the time added in a stoichiometric manner, has

Development and mechanistic studies of calcium–BINOL phosphate-catalyzed hydrocyanation of hydrazones

• Carola Tortora,
• Christian A. Fischer,
• Sascha Kohlbauer,
• Alexandru Zamfir,
• Gerd M. Ballmann,
• Jürgen Pahl,
• Sjoerd Harder and
• Svetlana B. Tsogoeva

Beilstein J. Org. Chem. 2025, 21, 755–765, doi:10.3762/bjoc.21.59

• Erlangen-Nürnberg, Nikolaus-Fiebiger Strasse 10, 91058 Erlangen, Germany Department of Chemistry and Pharmacy, Chair of Inorganic and Organometallic Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstrasse 1, 91058 Erlangen, Germany 10.3762/bjoc.21.59 Abstract Asymmetric

• enantioselectivity achieved with the calcium catalyst remains modest, mainly due to competing pathways for the Z- and E-hydrazone isomers leading to opposite enantiomers. The experimental results confirm these computational proposals. Keywords: asymmetric synthesis; calcium–BINOL phosphate catalysis; hydrocyanation

• through calcium catalysis [8][9][10]. Asymmetric synthesis has also been achieved via, e.g., 1,4-addition and [3 + 2] cycloaddition of 3-tetrasubstituted oxindoles with a calcium Pybox catalyst [11][12], or through enantioselective Friedel–Crafts and carbonyl–ene reactions [13]. Since the pioneering

Asymmetric synthesis of fluorinated derivatives of aromatic and γ-branched amino acids via a chiral Ni(II) complex

• Maurizio Iannuzzi,
• Thomas Hohmann,
• Michael Dyrks,
• Kilian Haoues,
• Katarzyna Salamon-Krokosz and
• Beate Koksch

Beilstein J. Org. Chem. 2025, 21, 659–669, doi:10.3762/bjoc.21.52

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

• Abstract The transition-metal-catalyzed asymmetric allylic substitution represents a pivotal methodology in organic synthesis, providing remarkable versatility for complex molecule construction. Particularly, the generation and utilization of chiral secondary alkylcopper species have received considerable

• attention due to their unique properties in stereoselective allylic substitution. This review highlights recent advances in copper-catalyzed asymmetric allylic substitution reactions with chiral secondary alkylcopper species, encompassing several key strategies for their generation: stereospecific

• asymmetric allylic alkylation (AAA) has been remarkable since its initial development in 1995, when Bäckvall and van Koten first reported moderate enantioselectivity using Grignard reagents with allylic acetates [21][22]. This discovery triggered extensive research endeavors, significantly expanding the

Asymmetric synthesis of β-amino cyanoesters with contiguous tetrasubstituted carbon centers by halogen-bonding catalysis with chiral halonium salt

• Yasushi Yoshida,
• Maho Aono,
• Takashi Mino and
• Masami Sakamoto

Beilstein J. Org. Chem. 2025, 21, 547–555, doi:10.3762/bjoc.21.43

• of its unique interaction in organic synthesis. Chiral halonium salts have been found to have strong halogen-bonding-donor abilities and work as powerful asymmetric catalysts. Recently, we have developed binaphthyl-based chiral halonium salts and applied them in several enantioselective reactions

• , which formed the corresponding products in high to excellent enantioselectivities. In this paper, the asymmetric synthesis of β-amino cyanoesters with contiguous tetrasubstituted carbon stereogenic centers by the Mannich reaction through chiral halonium salt catalysis is presented, which provided the

• corresponding products in excellent yields with up to 86% ee. To the best of our knowledge, the present paper is the first to report the asymmetric construction of β-amino cyanoesters with contiguous tetrasubstituted carbon stereogenic centers by the catalytic Mannich reaction. Keywords: asymmetric catalysis

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

• diastereoselectivity at 50 °C (Table 1, entry 16). Finally, the addition of molecular sieves was evaluated (Table 1, entries 17 and 18) affording in both cases lower yields for the reaction product. We also attempted asymmetric reactions using chiral organocatalysts to achieve an enantioselective outcome; however, we

• observed only racemic mixtures, likely due to the occurrence of a background reaction (details for asymmetric trials are provided in Supporting Information File 1). On the view of the results of the optimization process, we decided to study the reaction scope using the reaction conditions of entries 10 and

Unprecedented visible light-initiated topochemical [2 + 2] cycloaddition in a functionalized bimane dye

• Metodej Dvoracek,
• Brendan Twamley,
• Mathias O. Senge and
• Mikhail A. Filatov

Beilstein J. Org. Chem. 2025, 21, 500–509, doi:10.3762/bjoc.21.37

• bimanes studied: a) Cl2B (B), representing 90% of the disordered asymmetric unit, b) Me2B, not disordered with dotted line representing an intramolecular hydrogen bond, and c) Me4B showing the majority occupied (55%) N–N moiety. View of the molecular structure in the crystal of a) symmetry generated by

Organocatalytic kinetic resolution of 1,5-dicarbonyl compounds through a retro-Michael reaction

• James Guevara-Pulido,
• Fernando González-Pérez,
• José M. Andrés and
• Rafael Pedrosa

Beilstein J. Org. Chem. 2025, 21, 473–482, doi:10.3762/bjoc.21.34

• olefins with a wide range of nucleophiles, with many organocatalyzed asymmetric examples highlighted in the literature [23][24]. We have observed that the enantioenriched 1,5-dicarbonyl Michael adducts, synthesized via organocatalyzed reaction of cinnamaldehyde with benzyl phenyl ketone, undergo

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

• selective substrate and transition-state binding, and for which extensive synthetic development is known [350][351][352][353][354][355]; (iii) they are the lowest possible symmetry polymacrocyclic structure (removing one edge piece will result in a macrocycle) [356][357], meaning ordered asymmetric