Search results

Search for "chiral" in Full Text gives 980 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.

Formaldehyde surrogates in multicomponent reactions

  • Cecilia I. Attorresi,
  • Javier A. Ramírez and
  • Bernhard Westermann

Beilstein J. Org. Chem. 2025, 21, 564–595, doi:10.3762/bjoc.21.45

Graphical Abstract
  • is a very interesting alternative for the synthesis of P-chiral α-aminophosphorous compounds without formaldehyde due to the straightforward procedure, the good yields observed, and the absence of byproducts compared to more conventional methods (Pudovik reaction or Kabachnik–Fields MCR reaction) [72
PDF
Album
Review
Published 13 Mar 2025

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

Graphical Abstract
  • , Chiba 263-8522, Japan 10.3762/bjoc.21.43 Abstract β-Amino cyanoesters are important scaffolds because they can be transformed into useful chiral amines, amino acids, and amino alcohols. Halogen bonding, which can be formed between halogen atoms and electron-rich chemical species, is attractive because
  • 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
PDF
Album
Supp Info
Letter
Published 12 Mar 2025

Binding of tryptophan and tryptophan-containing peptides in water by a glucose naphtho crown ether

  • Gianpaolo Gallo and
  • Bartosz Lewandowski

Beilstein J. Org. Chem. 2025, 21, 541–546, doi:10.3762/bjoc.21.42

Graphical Abstract
  • – anionic, Lys – cationic, Leu – hydrophobic) affects their binding by the receptor. Additionally, to probe whether the chiral glucose backbone of the receptor allows to achieve selective binding of one enantiomer of tryptophan over the other we used both ʟ- and ᴅ-tryptophan as guests. The binding of amino
PDF
Album
Supp Info
Letter
Published 10 Mar 2025

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

Graphical Abstract
  • 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
PDF
Album
Supp Info
Letter
Published 10 Mar 2025

Synthesis of the aggregation pheromone of Tribolium castaneum

  • Biyu An,
  • Xueyang Wang,
  • Ao Jiao,
  • Qinghua Bian and
  • Jiangchun Zhong

Beilstein J. Org. Chem. 2025, 21, 510–514, doi:10.3762/bjoc.21.38

Graphical Abstract
  • is a destructive stored product pest. The aggregation pheromone of this pest was prepared via a new and effective strategy. The key steps include the ring-opening reaction of chiral 2-methyloxirane, the stereospecific inversion of chiral secondary tosylate, Li2CuCl4-catalyzed coupling of tosylate
  • with Grignard reagent, and oxidation with RuCl3/NaIO4. Keywords: aggregation pheromone; chiral 2-methyloxirane; red flour beetle; total synthesis; Introduction The red flour beetle, Tribolium castaneum Herbst (Coleoptera: Tenebrionidae), is a cosmopolitan, destructive stored product pest [1], which
  • , Mori and Phillips achieved the complete separation of the derivatives from the four stereoisomers by reversed-phase HPLC at −54 °C, and revealed that the natural pheromone consists of four stereoisomers of 4,8-dimethyldecanal (Figure 1) [16][17]. Previous syntheses mainly focused on chiral sources of
PDF
Album
Supp Info
Letter
Published 06 Mar 2025

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

Graphical Abstract
  • separated using chiral resolution. This involves separating the two enantiomers by converting the racemic mixture into a pair of diastereoisomers with the help of a chiral compound. The resulting diastereoisomers can be separated based on their physical properties using crystallization, distillation, or
  • chromatography [1]. Sometime later, kinetic resolution (KR) emerged. This method is based on the different reaction rates of each enantiomer in a racemic mixture when they are reacted with a reagent, a chiral catalyst, or an enzyme. This process results in obtaining the less reactive enantioenriched enantiomer
  • processes with low catalyst loading. It involves the kinetic resolution of alcohols, amines, and esters using chiral phosphoric acids [6][7][8][9][10][11][12][13] and sulfoximines with enals using chiral N-heterocyclic carbene (NHC) catalysts [14]. Additionally, these processes have been conducted using
PDF
Album
Supp Info
Full Research Paper
Published 03 Mar 2025

Electrochemical synthesis of cyclic biaryl λ3-bromanes from 2,2’-dibromobiphenyls

  • Andrejs Savkins and
  • Igors Sokolovs

Beilstein J. Org. Chem. 2025, 21, 451–457, doi:10.3762/bjoc.21.32

Graphical Abstract
  • ]. In addition, cyclic diaryl λ3-bromanes have been successfully employed as halogen-bonding organocatalysts in Michael addition [8] and their chiral variants were efficient in catalyzing enantioselective Mannich reactions of ketimines with cyanomethyl coumarins [9] and malonic esters [10]. These
PDF
Album
Supp Info
Letter
Published 27 Feb 2025

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

Graphical Abstract
  • groups) with little [73], if any, transition-state binding [36][80][81]. Thus, these macrocycles depend on the catalytic concept of organization; polarization is a minor contributor. Size-exclusion and regioselective outcomes are possible [56][82][83][84][85], and symmetric arrays of chiral units (like
  • catalysis [229]. Methods to study the structural detail of catalysis in frameworks remain limited, and crucial techniques like solution-phase NMR are rarely useful [22]. Enzyme encapsulation [230], and electro- and photocatalysis are known [228], and chiral and low symmetry MOFs are an exciting avenue
  • , although the synthesis and characterization (particularly crystallization) of low-symmetry structures remains challenging [227][231][232]. Likewise, COFs hosting chiral organocatalysts are known (Figure 6B) [226][233]. Frameworks are well-suited to hosting opposing reactive functionalities (e.g., acids and
PDF
Album
Supp Info
Perspective
Published 24 Feb 2025

The effect of neighbouring group participation and possible long range remote group participation in O-glycosylation

  • Rituparna Das and
  • Balaram Mukhopadhyay

Beilstein J. Org. Chem. 2025, 21, 369–406, doi:10.3762/bjoc.21.27

Graphical Abstract
  • ether-type chiral auxiliary group for protection of the hydroxy group in the C-2 position was devised by Boons et al. in 2005 which opened a new avenue in oligosaccharide synthesis. Auxiliary group indicates a substituted ethyl protection which has a nucleophilic centre that can donate electrons in the
  • tartgeted reaction [148]. A proper modulation of the stereochemistry of the chiral auxiliary group allows to obtain both the 1,2-cis and 1,2-trans stereoselective glycoside product (Scheme 17) [149]. An O-2 chiral auxiliary group in the glycoside donor interacts with the anomeric carbon to produce a decalin
  • 1,2-cis decalin 101 facilitating the formation of 1,2-trans glycosidic product 102. This protocol was further demonstrated successfully by the same research group by using the easily available R and S enantiomers of the first-generation chiral auxiliary, ethyl mandelate. Similarly, a (1S)-phenyl-2
PDF
Album
Review
Published 17 Feb 2025

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

Graphical Abstract
  • , the Chang group elegantly unveiled a protocol for an enantioselective C–N bond formation, introducing δ-lactams from dioxazolones using a copper(I) catalyst and a chiral BOX ligand [74]. As shown in Scheme 2, dioxazolones containing aryl and heteroaryl groups were converted into the corresponding
  • amidation process of dioxazolones. Dioxazolone 1 binds to the chiral copper complex 3, generating the adduct INT-1. Decarboxylation then occurs, forming the copper nitrenoid intermediate INT-2, subsequently undergoing hydrogen atom transfer in a regioselective manner to afford INT-3. The related acyl
  • nitrenoid intermediate was characterized by the same group [75]. Further radical rebound from INT-4 induces the enantioselective C–N bond formation. Finally, the desired product 2 is released from INT-4, regenerating the active chiral copper species to participate in the catalytic cycle. 1.2 C(sp2)–H
PDF
Album
Review
Published 22 Jan 2025

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

Graphical Abstract
  • ][22][23][24]. Moreover, copper-catalyzed asymmetric radical cross-coupling has advanced significantly over the past decade [25][26][27], with notable examples including Liu and Stahl’s enantioselective cyanation of benzylic C–H bonds using a Cu/chiral bisoxazoline catalyst [28], along with the Peters
  • enantioselective C–H alkynylation of ferrocene carboxamides with terminal alkynes by using Cu/BINOL and an electrocatalytic system (Figure 5) [49]. 8-Aminoquinoline-assisted C–H functionalization provided planar chiral ferrocenes with high yield and enantioselectivity. This reaction can be applied to a wide range
  • asymmetric C(sp3)–H alkynylation of tertiary cyclic amines by merging Cu(II)/TEMPO catalysis with electrochemistry to yield chiral C1-alkynylated tetrahydroisoquinolines (THIQs) (Figure 5) [50]. As a co-catalytic redox mediator, TEMPO plays an essential role in the formation of iminium intermediate 15 and in
PDF
Album
Review
Published 16 Jan 2025

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

Graphical Abstract
  • -methylthiazole-2-carboxaldehyde as chelating agent, in the presence of copper triflate and the chiral diamine ligand 28. The stereoselectivity was directed by the formation of a proposed catalyst complex 29 involving two molecules of Schiff base (Scheme 22) [39]. The three-component annulation of aldehydes
PDF
Album
Review
Published 14 Jan 2025

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

Graphical Abstract
  • becoming increasingly relevant also in medicine. Many axially chiral compounds are important as catalysts in asymmetric catalysis or have chiroptical properties. This review overviews recent progress in the synthesis of axially chiral compounds via asymmetric organocatalysis. Atroposelective
  • organocatalytic reactions are discussed according to the dominant catalyst activation mode. For covalent organocatalysis, the typical enamine and iminium modes are presented, followed by N-heterocyclic carbene-catalyzed reactions. The bulk of the review is devoted to non-covalent activation, where chiral Brønsted
  • ; Introduction Stereoselective catalytic formation of chiral compounds is one of the critical tasks of modern organic synthesis [1]. The catalytic formation of compounds with a center of chirality has been the focus of countless works and can now be considered a matured area. On the other hand, the generation of
PDF
Album
Review
Published 09 Jan 2025

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

Graphical Abstract
  • slight decrease observed for 5ac, with chiral (R)-1-((1-phenylethyl)amino)-1,2-benziodoxol-3-(1H)-one (2c), can be attributed to potential steric hindrance induced by the methyl group attached to the benzylic carbon, which may hinder the nucleophile’s access to the electrophilic center of the HIR. The
PDF
Album
Supp Info
Full Research Paper
Published 19 Dec 2024

Efficient synthesis of fluorinated triphenylenes with enhanced arene–perfluoroarene interactions in columnar mesophases

  • Yang Chen,
  • Jiao He,
  • Hang Lin,
  • Hai-Feng Wang,
  • Ping Hu,
  • Bi-Qin Wang,
  • Ke-Qing Zhao and
  • Bertrand Donnio

Beilstein J. Org. Chem. 2024, 20, 3263–3273, doi:10.3762/bjoc.20.270

Graphical Abstract
  • ] in combination with tunable absorption and emission of visible light. Polar nematic phase [23] and chiral columnar phase materials [24] based on polar fluorobenzene rings have also recently emerged as interesting new classes of fluorous materials, revealing their enormous potential in the high-tech
PDF
Album
Supp Info
Full Research Paper
Published 16 Dec 2024

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

Graphical Abstract
  • -heterocycles using various catalytic systems such as chiral metal catalysts, chiral Lewis acids or chiral organocatalysts. This review presents an overview of the recent advances in enantioselective cyclization reactions of 1-azadienes catalyzed by non-covalent organocatalysts. Keywords: α,β-unsaturated
  • covered in this review are hydrogen-bond donors such as thioureas and squaramides, Brønsted bases such as tertiary amines, and Brønsted acids such as chiral phosphoric acids. As depicted in Figure 4, a bifunctional squaramide is able to activate both an α,β-unsaturated imine through hydrogen bonding with
  • the squaramide moiety and a nucleophile through deprotonation as Brønsted base. On the other hand, a chiral phosphoric acid provides a confined chiral environment where the reactants are approached, activating both the azadiene by interaction with the acidic hydrogen and a dienophile bearing a
PDF
Album
Review
Published 10 Dec 2024

Ceratinadin G, a new psammaplysin derivative possessing a cyano group from a sponge of the genus Pseudoceratina

  • Shin-ichiro Kurimoto,
  • Kouta Inoue,
  • Taito Ohno and
  • Takaaki Kubota

Beilstein J. Org. Chem. 2024, 20, 3215–3220, doi:10.3762/bjoc.20.267

Graphical Abstract
  • of psammaplysin A remained ambiguous for approximately 30 years but was determined in 2015 by Kurtán, Garson, and co-workers through a comparison of experimental and calculated electronic circular dichroism data, as well as a method employing Trost's chiral anisotropic reagents [6]. More recently
PDF
Album
Supp Info
Full Research Paper
Published 09 Dec 2024

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

Graphical Abstract
  • strategy, the control of the stereoselectivity of the intramolecular aza-Michael addition could be envisaged with various chiral catalysts in further studies. These heterocyclic hydrazino acids, when incorporated into the peptidic structure, appear to confer an extended conformation. These interesting
PDF
Album
Supp Info
Full Research Paper
Published 04 Dec 2024

Hypervalent iodine-mediated intramolecular alkene halocyclisation

  • Charu Bansal,
  • Oliver Ruggles,
  • Albert C. Rowett and
  • Alastair J. J. Lennox

Beilstein J. Org. Chem. 2024, 20, 3113–3133, doi:10.3762/bjoc.20.258

Graphical Abstract
  • formed. The use of a chiral aryl iodide was tested, which gave products with low enantiomeric excess. However, these preliminary trials represent the first example of a catalytic, enantioselective HVI-mediated fluorocyclisation. The authors proposed a mechanism (Scheme 4) for this reaction that involved
  • from the styrenyl starting materials is stereoselective, giving the syn-diasteroisomer in high yields. A chiral iodoarene catalyst 16 was employed, along with a stoichiometric sacrificial oxidant, to give good to excellent levels of enantioselectivity. This elegant strategy led to a variety of β
  • aminofluorination using BF3·Et2O with a chiral aryliodide 16 catalyst (Scheme 20) [44]. The study successfully obtained various chiral fluorinated oxazine products 38 with high enantioselectivity (up to >99% ee) and diastereoselectivity (up to >20:1 dr). Control experiments showed that using Py·9HF or Et3N·3HF as
PDF
Album
Review
Published 28 Nov 2024

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

Graphical Abstract
  • enantiomeric excess (ee) up to 5.5% [70]. Related catalytic systems based on amphiphilic 5-(cyclic-secondary-amine)-10,15,20-tris(4-sulfonatophenyl)porphyrin macrocycles 58–61 act as switchable organocatalysts for Michael and aldol reactions in water [68][69]. The macrocycles 58–61 containing different chiral
  • hypothesis that the reaction would work in acidic environment using catalysts insensitive to pH-induced aggregation. In the same aldol reaction, using of macrocycles 60 and 61 containing chiral secondary amine moieties provided not only good yields, but also good diastereoselectivities; chiral HPLC analysis
  • organocatalysis can be summarized in the following statements: (1) using highly distorted nonplanar macrocyclic systems with an easy access to inner –NHs and basic imine moieties (by Senge, Hill, and co-workers [61][62][63]), (2) using monomeric and aggregated forms of achiral/chiral planar amphiphilic porphyrin
PDF
Album
Review
Published 27 Nov 2024

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

Graphical Abstract
  • ; Introduction Enantioenriched α-allenic alcohols are an important class of chiral building blocks used for the chemical synthesis of biologically relevant molecules [1][2][3][4][5]. Their strength comes from the rich synthetic versatility [6][7][8][9] and biological relevance [10] of the allene functionality
  • . Accordingly, the development of efficient access to optically active chiral α-allenic alcohols continues to be of significant interest in organic chemistry [11][12][13]. The asymmetric catalytic addition of allenylation reagents to aldehydes provides direct access to chiral α-allenic alcohols in an
  • stable allenyltrichlorosilane that affords undesired homopropargylic alcohols [35][36] (Scheme 2b). Furthermore, Iseki [35] and Nakajima [36] evaluated only one chiral catalyst in their independent studies (i.e., no catalyst structure–reactivity and selectivity relationship study). In this context, we
PDF
Album
Supp Info
Letter
Published 25 Nov 2024

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

Graphical Abstract
  • ., the type of alkylmalonate it incorporates into a growing PK intermediate [61]. Furthermore, Xiang et al. reported recently that the stereochemistry of each new chiral center resulting from each alkylmalonate BB incorporation can be predicted based on the corresponding ketoreductase domain sequence [83
PDF
Album
Perspective
Published 20 Nov 2024
Graphical Abstract
  • from the chiral nature of the CD molecule, and its behavior fits well with the theoretical consideration. As comprehensively described [32], CD-based rotaxanes are typically synthesized by two methods: (1) the end-capping method (route a1, a2) in which the formation of a pseudorotaxane structure first
PDF
Album
Review
Published 19 Nov 2024

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

Graphical Abstract
  • formation of peroxide 9. The enantioselective peroxidation of alkenes 10 with TBHP with the formation of the optically active products 11 was carried out in good yields and low ee by the use of in situ-generated chiral bisoxazoline–copper(I) complexes (Scheme 7) [43]. Studying the oxidation of α-pinene (12
  • . The oxidation of benzyl alcohol 62 with TBHP results in aldehyde C, HAT from which by tert-butoxy radical A leads to the C-centered radical D. Subsequent recombination of radicals D and B provides the target product 63. An enantioselective peroxidation method of alkylaromatics with TBHP using chiral
PDF
Album
Review
Published 18 Nov 2024

4,6-Diaryl-5,5-difluoro-1,3-dioxanes as chiral dopants for liquid crystal compositions

  • Maurice Médebielle,
  • Peer Kirsch,
  • Jérémy Merad,
  • Carolina von Essen,
  • Clemens Kühn and
  • Andreas Ruhl

Beilstein J. Org. Chem. 2024, 20, 2940–2945, doi:10.3762/bjoc.20.246

Graphical Abstract
  • Darmstadt, Germany Institute of Materials Science, Technical University of Darmstadt, Peter-Grünberg-Str. 2, D-64287 Darmstadt, Germany 10.3762/bjoc.20.246 Abstract Two racemic anti-4,6-diphenyl-5,5-difluoro-1,3-dioxanes were prepared and the corresponding enantiomers were evaluated as potential new chiral
  • dopants for liquid-crystal compositions. Keywords: chiral dopant; chirality; cholesteric phase; diols; fluorine; helical twisting power; liquid crystal; Introduction Liquid crystals for use in liquid crystal displays (LCDs) have become one of the most prominent application areas of fluoroorganic
  • chemistry [1][2][3]. In particular, cholesteric, i.e., chiral nematic, liquid crystals (LCs) are attractive for many display applications due to their chiroptical characteristics as well as the selective reflection of light giving rise to Bragg interference colors [4]. Cholesteric LCs can be obtained either
PDF
Album
Supp Info
Full Research Paper
Published 14 Nov 2024
Other Beilstein-Institut Open Science Activities