The application of desymmetric enantioselective reduction of cyclic 1,3-dicarbonyl compounds in the total synthesis of terpenoid and alkaloid natural products

• Dong-Xing Tan and
• Fu-She Han

Beilstein J. Org. Chem. 2025, 21, 2085–2102, doi:10.3762/bjoc.21.164

• shortage of natural product sources. Nevertheless, the asymmetric total synthesis of terpenoid and alkaloid natural products presents significant challenges due to their complex and diverse ring systems and the presence of multiple stereocenters, including all-carbon quaternary stereocenters. Consequently

• , the development of novel methods and strategies to achieve efficient asymmetric total synthesis of complex terpenoid and alkaloid natural products has drawn considerable attention from synthetic chemists. Over the past decades, the development of desymmetric enantioselective reduction strategy of

• co-workers accomplished the first asymmetric total synthesis of (+)-aplysiasecosterol A (6) by employing a desymmetric enantioselective reduction strategy of 1,3-cyclopentanedione derivative as the key transformation [14]. Their synthesis features a highly efficient desymmetric enantioselective

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

• catalytic asymmetric methods [26], we intended to probe this biomimetic oxidative cyclization transformation [27][28]. In 2013, we first used monocerin as a model target molecule to initiate our study (Scheme 3a). Starting from benzaldehyde 11 with an isopropyl group on the hydroxy group in 4-position

• powerful routes to the asymmetric total synthesis of these bioactive molecules. The precursors of the key bioinspired transformations 36, 38 and 40 were efficiently synthesized from simple fragments aryl aldehyde 42 or 43, phenylboronic acid 44 and chiral auxiliary-containing building block 45, through

Measuring the stereogenic remoteness in non-central chirality: a stereocontrol connectivity index for asymmetric reactions

• Ivan Keng Wee On,
• Yu Kun Choo,
• Sambhav Baid and
• Ye Zhu

Beilstein J. Org. Chem. 2025, 21, 1995–2006, doi:10.3762/bjoc.21.155

• Ivan Keng Wee On Yu Kun Choo Sambhav Baid Ye Zhu Department of Chemistry, Faculty of Science, National University of Singapore, 3 Science Drive 2, Singapore 117543 10.3762/bjoc.21.155 Abstract Despite the rapid development of asymmetric synthesis, judging the remoteness of stereocontrol has

• remained an intuitive and empirical practice, particularly for reactions that create non-central chirality. We put forward a stereocontrol connectivity index to parameterize asymmetric reactions according to the bond connectivity relationships between the prochiral stereogenic elements, the reactive sites

• chiral molecules. Keywords: asymmetric reactions; axial chirality; catalysis; planar chirality; stereocontrol; Introduction Chirality is a ubiquitous and fundamental phenomenon in nature and thus holds an irreplaceable position in organic synthesis. At its most rudimental definition, chirality in a

Asymmetric total synthesis of tricyclic prostaglandin D2 metabolite methyl ester via oxidative radical cyclization

• Miao Xiao,
• Liuyang Pu,
• Qiaoli Shang,
• Lei Zhu and
• Jun Huang

Beilstein J. Org. Chem. 2025, 21, 1964–1972, doi:10.3762/bjoc.21.152

• available has prevented its practical use, and synthesis methods for tricyclic-PGDM methyl ester are required. Based on the utilization of oxidative radical cyclization for the stereoselective construction of the cyclopentanol subunit with three consecutive stereocenters, we describe an asymmetric total

• synthesis of tricyclic-PGDM methyl ester in 9 steps and 8% overall yield. Keywords: asymmetric total synthesis; oxidative radical cyclization; tricyclic prostaglandin D2 metabolite methyl ester; Introduction Prostaglandins (PGs), a family of hormone-like lipid compounds, are ubiquitous natural products

• ring system with the appropriate functional groups in place for attaching the remaining groups is a highly important task for the asymmetric total synthesis of PGs and analogues [10][11][12][13]. The groups of Aggarwal [14], Hayashi [15], and Zhang [16] have reported bond-disconnection strategies for

Enantioselective desymmetrization strategy of prochiral 1,3-diols in natural product synthesis

• Lihua Wei,
• Rui Yang,
• Zhifeng Shi and
• Zhiqiang Ma

Beilstein J. Org. Chem. 2025, 21, 1932–1963, doi:10.3762/bjoc.21.151

• biologically active molecules. Based on the reaction types, three strategies are discussed: enzymatic acylation, transition-metal-catalyzed acylation, and local desymmetrization. Keywords: asymmetric synthesis; desymmetrization; 1,3-diols; natural product; total synthesis; Introduction Natural products

• isolated from organisms are often asymmetric in their spatial structures, and these unique spatial structures are precisely what lead to their diverse biological activities [1][2][3][4]. For the synthesis of these natural products or bioactive molecules, chemists usually need to consider how to carry out

• asymmetric synthesis of them, driving the advancement of asymmetric methodologies [5][6][7][8][9]. Enantioselective desymmetrization of symmetric substrates has emerged as a pivotal methodology for the construction of chiral centers over the past few decades [10][11][12][13]. A series of reaction types have

Synthesis of N-doped chiral macrocycles by regioselective palladium-catalyzed arylation

• Shuhai Qiu and
• Junzhi Liu

Beilstein J. Org. Chem. 2025, 21, 1917–1923, doi:10.3762/bjoc.21.149

• that inherently lacks symmetry [8][9]. One of the most typical representatives are calix[4]arenes (Figure 1a), first reported by Böhmer in 1994 [10], where asymmetric substitutions on the macrocyclic rim induce inherent chirality. Subsequent advancements have identified other inherent chiral systems

• asymmetric geometry due to the fusion of the pyrene unit (Figure 2c). The two pyrene units are oriented antiparallel, which is distinctive from that observed in 3a and MC2. Notably, the pyrene-fused moiety is highly curved with a bending angle of 85.3° as defined by the angle of the planes of the terminal

Stereoselective electrochemical intramolecular imino-pinacol reaction: a straightforward entry to enantiopure piperazines

• Margherita Gazzotti,
• Fabrizio Medici,
• Valerio Chiroli,
• Laura Raimondi,
• Sergio Rossi and
• Maurizio Benaglia

Beilstein J. Org. Chem. 2025, 21, 1897–1908, doi:10.3762/bjoc.21.147

• products, agrochemicals, and pharmacologically active compounds. Enantiomerically pure 1,2-diamines and their derivatives are also increasingly used in stereoselective synthesis, particularly as chiral auxiliaries or as ligands for metal complexes in asymmetric catalysis [1]. Metal-based reductants

Chiral phosphoric acid-catalyzed asymmetric synthesis of helically chiral, planarly chiral and inherently chiral molecules

• Wei Liu and
• Xiaoyu Yang

Beilstein J. Org. Chem. 2025, 21, 1864–1889, doi:10.3762/bjoc.21.145

• with the more recently introduced inherent chirality. As one of the most prominent chiral organocatalysts, chiral phosphoric acid (CPA) catalysis has proven highly effective in synthesizing centrally and axially chiral molecules. However, its potential in the asymmetric construction of other types of

• molecular chirality has been investigated comparatively less. This Review provides a comprehensive overview of the recent emerging advancements in asymmetric synthesis of planarly chiral, helically chiral and inherently chiral molecules using CPA catalysis, while offering insights into future developments

• within this domain. Keywords: asymmetric catalysis; chiral phosphoric acid; helical chirality; inherent chirality; planar chirality; Introduction Since the seminal works by Akiyama [1] and Terada [2] et al. in 2004 demonstrated the application of BINOL-derived chiral phosphoric acids (CPAs) in

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

• , bottom), the thermal lifetimes drop significantly [38]. It is thus crucial to take into account the asymmetric nature of the imine bond and the steric hindrance of the substituents in the design of these photoswitches. For a detailed analysis of the structure–property relationship of these compounds we

• be synthesised through oxidation of aminoheteroarenes 12 (Scheme 4A) or reduction of nitroheteroarenes 13 (B). Bayer–Mills coupling (Scheme 4C) is suitable for both symmetric and asymmetric targets, usually in acidic conditions. Basic conditions [14] are more effective with very electron-poor

• aromatic amines. Another strategy for both symmetric and asymmetric targets is the azo coupling of a diazonium salt 15 (Scheme 5A) with a nucleophile, which can be a (hetero)aromatic 16 [29] (B), a lithiated ring 19 [39] (C), or a precursor 20a,b [29][32][40] (D). In case of more than one reactive position

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