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Search for "chiral" in Full Text gives 1039 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.
Stereoselective electrochemical intramolecular imino-pinacol reaction: a straightforward entry to enantiopure piperazines
Beilstein J. Org. Chem. 2025, 21, 1897–1908, doi:10.3762/bjoc.21.147
- Margherita Gazzotti Fabrizio Medici Valerio Chiroli Laura Raimondi Sergio Rossi Maurizio Benaglia Dipartimento di Chimica, Università degli Studi di Milano, via Golgi 19, IT-20133 Milano, Italy 10.3762/bjoc.21.147 Abstract The stereoselective electroreductive intramolecular coupling of chiral
- applications in the preparation of chiral ligands. Keywords: chiral piperazines; electrosynthesis; flow chemistry; green chemistry; imino-pinacol coupling; Introduction Vicinal diamines represent a highly valuable class of compounds that, over the past decades, have found widespread application in natural
- 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
Beilstein J. Org. Chem. 2025, 21, 1864–1889, doi:10.3762/bjoc.21.145
- .21.145 Abstract Chiral molecules, distinguished by nonsuperimposability with their mirror image, play crucial roles across diverse research fields. Molecular chirality is conventionally categorized into the following types: central chirality, axial chirality, planar chirality and helical chirality, along
- 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
Photoswitches beyond azobenzene: a beginner’s guide
Beilstein J. Org. Chem. 2025, 21, 1808–1853, doi:10.3762/bjoc.21.143
- also been explored. Unlike sulphoxides, sulphones are not chiral. Both sulphone and sulphoxide are more electron-deficient than hemithioindigo, which induces a blue-shift of the absorption spectrum (Figure 16, centre) [88]. The photophysical properties of iminothioindoxyl 72 (Scheme 22, top), although
- on the desired indigoid photoswitch, synthesis may show varying levels of difficulty. Nevertheless, if compared to diarylethenes or fulgides, indigoids are typically easier to obtain. Examples The chiral hemithioindigo sulphoxide 98 has been demonstrated to have unidirectional rotation upon
Synthesis of chiral cyclohexane-linked bisimidazolines
Beilstein J. Org. Chem. 2025, 21, 1786–1790, doi:10.3762/bjoc.21.140
- Changmeng Xi Qingshan Sun Jiaxi Xu State Key Laboratory of Chemical Resource Engineering, Department of Organic Chemistry, College of Chemistry, Beijing University of Chemical Technology, Beijing 100029, People’s Republic of China 10.3762/bjoc.21.140 Abstract Both chiral bisoxazolines and
- 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
- , condensation of N-sulfonylated 1,2-diphenylethane-1,2-diamines and cyclohexane-1,2-dicarboxylic acid, and the final cyclization with the in situ generated Hendrickson reagent. Keywords: bisimidazoline; cyclohexane; cyclohexane-1,2-dicarboxylic acid; 1,2-diphenylethane-1,2-diamine; Introduction Chiral
Research progress on calixarene/pillararene-based controlled drug release systems
Beilstein J. Org. Chem. 2025, 21, 1757–1785, doi:10.3762/bjoc.21.139
- chiral CA named chiral azo-calix[4]arene derivative (FC4AD) (Figure 10) [117]. Its interaction with enantiomers of aminoindanol in solution was investigated. It was found that FC4AD has high selective binding and release for (1R,2S)-1-amino-2-indanol, forming a 1:1 complex. S-phenethylamine was used as a
- chiral ligand, which was modified on the upper rim of calixarene through hydrogen bonding. An azobenzene group was introduced as the photo-regulating part at the upper edge of calixarene. The alkyne at the lower edge of FC4AD was used to form self-assembled monolayers (SAMs) on a silicon surface through
- Cu-catalyzed click chemistry to construct a photo-responsive macroscopic switch. This switch can achieve photo-controlled chiral reversible recognition of (1R,2S)-1-amino-2-indanol through changes in contact angle, and it holds promise for applications in chiral drug controlled release and other
Unique halogen–π association detected in single crystals of C–N atropisomeric N-(2-halophenyl)quinolin-2-one derivatives and the thione analogue
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
- halogen may act as an electron donor rather than an acceptor, and the interaction can be better described as an n–π* interaction involving the lone pair on the halogen atom. The results shown in Figure 1 suggest that in the case of chiral compounds, the corresponding racemic and enantioenriched forms
- 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
Beilstein J. Org. Chem. 2025, 21, 1737–1741, doi:10.3762/bjoc.21.136
- chiral HPLC. This confirmed that no erosion of enantiomeric purity had happened during the deprotection stage. With the enantioenriched vinyloxazoline S-6 in hand, we explored the reaction scope involving its electron-deficient double bond. Unfortunately, the olefin appeared unreactive or gave a mixture
- . Further scale-up could be achieved by switching to flow conditions, or designing a continuous tank reactor [27]. Several attempts were made to explore enantioenriched vinyloxazoline 6 as a chiral building block. While additions to the double bond were not successful, vinyloxazoline 6 was found to be a
3,3'-Linked BINOL macrocycles: optimized synthesis of crown ethers featuring one or two BINOL units
Beilstein J. Org. Chem. 2025, 21, 1719–1729, doi:10.3762/bjoc.21.134
- , 45141 Essen, Germany 10.3762/bjoc.21.134 Abstract Chiral macrocycles hold significant importance in various scientific fields due to their unique structural and chemical properties. By controlling their size, shape, and substituents, chiral macrocycles offer a platform for designing and synthesizing
- highly efficient catalysts, chemosensors, and functional materials. We have recently made strides in developing macrocyclic organocatalysts; however, their synthesis remains challenging. In this work, we aimed to discover a straightforward method for producing a diverse range of chiral macrocycles
- , thereby enabling further exploration in the field of interlocked and macrocyclic organocatalysts. We successfully established optimized synthetic routes for the synthesis of chiral macrocycles containing one or two stereogenic units, featuring varying ring sizes and substituents (21 examples in total
Catalytic asymmetric reactions of isocyanides for constructing non-central chirality
Beilstein J. Org. Chem. 2025, 21, 1648–1660, doi:10.3762/bjoc.21.129
- ], 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
- ][26]. Beyond these great developments, recent efforts have successfully expanded the utility of isocyanides to access structurally diverse non-central chiral frameworks, further expanding their synthetic potential. The following sections highlight these fruitful achievements, organized by both the
- iodides (Scheme 1a) [27]. This transformation proceeded via two key steps, isocyanide insertion and desymmetric C(sp2)–H bond activation. By using phosphoramidite L1 as the chiral ligand, planar chiral pyridoferrocenes 2 were obtained in 61–99% yield with 72–99% ee. In addition, this catalytic system
Synthesis of optically active folded cyclic dimers and trimers
Beilstein J. Org. Chem. 2025, 21, 1603–1612, doi:10.3762/bjoc.21.124
- structures, such as one-handed helical and propeller-shaped structures, can be constructed by folding the π-conjugated system using [2.2]paracyclophane as the chiral crossing unit, leading to circularly polarized luminescence (CPL) properties. Chiral cyclic dimers and trimers were synthesized using planar
- chiral [2.2]paracyclophane-containing enantiopure ribbon-shaped compounds as the chiral monomers. Unicursal π-conjugated systems were folded at the [2.2]paracyclophane units, and exhibited good photoluminescence quantum efficiencies and CPL anisotropy factors. Opposite chiroptical properties were
- observed between the dimer and trimer, despite the same absolute configuration of the planar chiral [2.2]paracyclophane units, which was reproduced by theoretical studies. Keywords: circularly polarized luminescence; oligomer; [2.2]paracyclophane; planar chirality; Introduction Cyclophane is a general
pH-Controlled isomerization kinetics of ortho-disubstituted benzamidines: E/Z isomerism and axial chirality
Beilstein J. Org. Chem. 2025, 21, 1568–1576, doi:10.3762/bjoc.21.120
- axially chiral anilines [10][11] and a triazine molecule [9]. In particular, protonation of a remote basic site in N–C axially chiral anilines significantly increases the rotational barrier by attenuating resonance stabilization in the transition state. One important issue in this field is the development
- effect of the C–N rotation due to the decrease in pH. As the rotation of the C–N bond of the ortho-disubstituted benzamidine could be controlled by the protonation of the amidine moiety, we then focused on the chiral axis of the ortho-disubstituted benzamidine. Our DFT calculations suggested that the
- stability of the chiral axis, amidine 1, which has identical substituents on the amidine nitrogen and thus does not generate E/Z isomers, was selected. In the chiral HPLC analysis using an acidic eluent [MeCN/H2O (containing 0.5% CF3CO2H) 20:80], the trifluoroacetate salt of amidine 1 was observed as two
Synthesis of an aza[5]helicene-incorporated macrocyclic heteroarene via oxidation of an o-phenylene-pyrrole-thiophene icosamer
Beilstein J. Org. Chem. 2025, 21, 1561–1567, doi:10.3762/bjoc.21.119
- ] and pyrenylenes [17][18] were reported to adopt unique chiral arrangements depending on their stereochemistry. Helical motifs such as carbo[4]helicene and oxa[5]helicene were incorporated into cyclic structures, giving rise to cyclic carbo[4]helicenylene A and cyclic oxa[5]helicenylene-biphenylene B
Copper catalysis: a constantly evolving field
Beilstein J. Org. Chem. 2025, 21, 1477–1479, doi:10.3762/bjoc.21.109
- substitution reactions [1]. In particular, the authors elaborate the concept and recent developments in this field, which allows access to enantioenriched chiral enynes. Interestingly, the article also illustrates the effects of the copper salt and the ligand employed, as well as the influence of the substrate
- 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
Wittig reaction of cyclobisbiphenylenecarbonyl
Beilstein J. Org. Chem. 2025, 21, 1454–1461, doi:10.3762/bjoc.21.107
- Cyclobisbiphenylenecarbonyl (CBBC) represents a readily available chiral figure-eight macrocycle containing two carbonyl groups. However, the transformation of the carbonyl groups has been unexplored. Herein, we conducted the Wittig reaction of CBBC with methylenetriphenylphosphorane to furnish two chiral macrocycles
- formation between carbonyl and alkene units. Keywords: bathtub; chirality; cyclobisbiphenylenecarbonyl; figure-eight; Wittig reaction; Introduction Figure-eight π-conjugated molecules represent chiral macrocycles with a twisted crossover structure [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15
- ]. Various figure-eight π-systems including aromatic hydrocarbons, belt-type extended π-systems, and porphyrinoids have been reported. The structural twisting in figure-eight macrocycles leads to cross-linked conjugation at the molecular center and a highly symmetric chiral structure with D2-symmetry
Advances in nitrogen-containing helicenes: synthesis, chiroptical properties, and optoelectronic applications
Beilstein J. Org. Chem. 2025, 21, 1422–1453, doi:10.3762/bjoc.21.106
- versatile scaffolds for chiral optoelectronic applications. The incorporation of nitrogen enables precise modulation of electronic structures, redox characteristics, and intermolecular interactions, thereby enhancing performance in circularly polarized luminescence (CPL), thermally activated delayed
- fluorescence (TADF), and chiral sensing. Notably, recent developments have yielded π-extended, structurally robust, and stimuli-responsive azahelicenes exhibiting record-high dissymmetry factors (|gabs| and |glum|), elevated CPL brightness (BCPL), and efficient integration into CPL-OLEDs and redox-switchable
- , emphasizing their potential as next-generation chiral optoelectronic materials and outlining future directions toward multifunctional integration and quantum technological applications. Keywords: azahelicene; chiroptical properties; circularly polarized luminescence (CPL); heteroatom containing
Reactions of acryl thioamides with iminoiodinanes as a one-step synthesis of N-sulfonyl-2,3-dihydro-1,2-thiazoles
Beilstein J. Org. Chem. 2025, 21, 1397–1403, doi:10.3762/bjoc.21.104
- yields of 1,2-thiazoles 3aa–ae are slightly lower (70 vs 78%) than by method A. We also investigated the effect of chiral catalysts or ligands in the reaction of thioamide 1a with 2a; however, we were unable to achieve high enantiomeric purity of product 3aa (see Supporting Information File 1, Table S1
Oxetanes: formation, reactivity and total syntheses of natural products
Beilstein J. Org. Chem. 2025, 21, 1324–1373, doi:10.3762/bjoc.21.101
- 23) based on the rebound triplet mechanism [64]. The stereochemical behaviour of the reaction is controlled by a novel hydrogen-bonding chiral iridium photocatalyst 86, delivering oxetane products 87 in excellent enantiomeric excess. In this unique photocycloaddition mechanism, previously described
- 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
Recent advances and future challenges in the bottom-up synthesis of azulene-embedded nanographenes
Beilstein J. Org. Chem. 2025, 21, 1272–1305, doi:10.3762/bjoc.21.99
- CHCl3, AcOH and o-DCB [44]. The resulting mixture of brominated PAHs 30 and 31 was then subjected to single or double [3 + 2] annulation with various alkynes, leading to the extended structures 32 and 33. Notably, compound 33d can undergo Pd-catalysed dimerization, resulting in the formation of a chiral
- fused product 93, but only in 8% yield after oxidation with FeCl3, while the major product was 1,1′-biazulene 94, obtained in 88% yield (Scheme 14). Compound 94 could further be oxidized using FeCl3 to yield the partially fused chiral compound 95. More recently, Morin and co-workers explored various
Synthesis of β-ketophosphonates through aerobic copper(II)-mediated phosphorylation of enol acetates
Beilstein J. Org. Chem. 2025, 21, 1192–1200, doi:10.3762/bjoc.21.96
- various synthetically useful transformations, including alkene synthesis via Horner–Wadsworth–Emmons reaction [14][15], heterocycle construction [16][17], and the synthesis of chiral β-amino and β-hydroxy phosphonic acids [18][19]. Furthermore, they exhibit metal-complexing abilities [20], and anti
Synthetic approach to borrelidin fragments: focus on key intermediates
Beilstein J. Org. Chem. 2025, 21, 1135–1160, doi:10.3762/bjoc.21.91
- alcohols, 34 and ent-34, after recrystallization from hot hexane (100% ee by chiral phase HPLC, yield not reported). These alcohols were then treated with triphenylphosphine and iodine in the presence of imidazole to yield the iodides 35 and ent-35 (Scheme 2). The iodide intermediates were subsequently
- simple impurity removal from the key chiral intermediates through recrystallization, from which their exact structures could be elucidated by XRD crystallography. Zhou’s approach for constructing Omura’s C3–C11 fragment In 2018, Zhou and co-workers developed an efficient, high-yielding iterative
- stereoselectivity. The authors emphasized that, as the alkene moiety in 54 was in a terminal position, the stereoselectivity of the products was determined solely by the chiral environment of the catalysts. The application of this method to construct the C3–C11 fragment 60 of borrelidin is summarized in Scheme 8
A versatile route towards 6-arylpipecolic acids
Beilstein J. Org. Chem. 2025, 21, 1104–1115, doi:10.3762/bjoc.21.88
- aryl modifications in C6 position by utilising the chiral pool of a non-proteinogenic amino acid in combination with transition metal-catalysed cross-coupling reactions. Moreover, we present an in-depth NMR analysis of the key intermediate steps, which illustrates the conformational constraints in
- acid (7-ACA) from cephalosporin C by cephalosporin C acylase [37], was used as a chiral starting material. After esterification of both carboxylic acid functions followed by cyclization to the lactam [38][39], the six-membered ring structure was established as (R)-methyl 6-oxopipecolate (7) with a high
- abundant chiral pool building block provides an entry into ᴅ-pipecolic acid derivatives. However, the synthetic strategy is of course applicable to ʟ-aminoadipic acid as well. The minor diastereomer of the catalytic hydrogenation was assigned as (2R,6R)-9, based on the analysis of the coupling constants
Salen–scandium(III) complex-catalyzed asymmetric (3 + 2) annulation of aziridines and aldehydes
Beilstein J. Org. Chem. 2025, 21, 1087–1094, doi:10.3762/bjoc.21.86
- [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
- require dineopentyl aziridine-2,2-dicarboxylates to realize high enantioselectivity, while the synthesis of the chiral ligand N,N'-dioxide requires multiple steps. Herein, we present a convenient highly diastereo- and enantioselective synthesis of dialkyl 2,5-diaryl-1-sulfonyloxazolidine-2,2
- 35 h in the presence of commercially available Sc(OTf)3 (0.01 mmol, 5 mol %), only a trace amount of product 3aa was observed (Table 1, entry 1). When chiral ligand L1 (0.01 mmol) was added, a trace amount of product 3aa was obtained with 17% ee (Table 1, entry 2). The enantioselectivity increased to
Recent advances in synthetic approaches for bioactive cinnamic acid derivatives
Beilstein J. Org. Chem. 2025, 21, 1031–1086, doi:10.3762/bjoc.21.85
- -workers (2019) reported an enantioselective esterification via oxidative N-heterocyclic carbene (NHC)-catalyzed phthalaldehyde activation to form azolium ester intermediate 147 to give the chiral phthalidyl ester 146 with excellent enantiomeric ratio (Scheme 45B) [85]. Additionally, the reaction capacity
Pd-Catalyzed asymmetric allylic amination with isatin using a P,olefin-type chiral ligand with C–N bond axial chirality
Beilstein J. Org. Chem. 2025, 21, 1018–1023, doi:10.3762/bjoc.21.83
- Advanced Academic Research (IAAR), Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan 10.3762/bjoc.21.83 Abstract In this study, we implemented the P,olefin-type chiral ligand (aR)-(−)-6, which contains a cyclohexyl group and a cinnamoyl group on the nitrogen atom, in the Pd-catalyzed
- 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
Beilstein J. Org. Chem. 2025, 21, 999–1009, doi:10.3762/bjoc.21.81
- column chromatography was required during this process, the synthetic route is highly practical. The enantioselective annulation of tertiary enamide 28 with enoldiazoacetate 29 was then explored under the catalysis of a chiral dirhodium catalyst. While Doyle and co-workers had previously reported an
- elegant [2 + 3] cycloaddition of secondary enecarbamates [28], the extension of this reaction to enamides lacking an N–H group is a notable advancement. After extensive optimization, the chiral dirhodium catalyst cat. 1 was found to be most capable in terms of both stereocontrol and efficiency. The use of
- alkaloids, though it features a truncated cyclopentane rather than the characteristic cyclohexane or cyclohexene. In their optimization studies, the authors found the sequential catalysis of a chiral binol–Ti complex and BF3·Et2O to be the most efficient, providing products 39 in high yields with excellent
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