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

• prochiral 2-aryloxyisophthalaldehydes 57a,b with a range of aliphatic and aromatic alcohols 58a–g, as well as heteroaromatic amines 60 (Scheme 19). Chiral diaryl ethers of this type received increased attention lately. Biju, Gao, Zhang, and Zeng groups all reported high degrees of yields and

Towards an asymmetric β-selective addition of azlactones to allenoates

• Behzad Nasiri,
• Ghaffar Pasdar,
• Paul Zebrowski,
• Katharina Röser,
• David Naderer and
• Mario Waser

Beilstein J. Org. Chem. 2024, 20, 1504–1509, doi:10.3762/bjoc.20.134

• synthesis approaches. Our group has a longstanding focus on the development of asymmetric organocatalytic methods to access non-natural chiral α- and β-AA [14][15][16][17][18][19]. Hereby we are especially interested in utilizing simple (prochiral) starting materials and carry out stereoselective α

Synthetic applications of the Cannizzaro reaction

• Bhaskar Chatterjee,
• Dhananjoy Mondal and
• Smritilekha Bera

Beilstein J. Org. Chem. 2024, 20, 1376–1395, doi:10.3762/bjoc.20.120

• yield (92%) and formed the diol 77, after the removal of the Boc-protecting group, where the prochiral hydroxymethyl groups ultimately paved the way towards the natural products (Scheme 22). Bernhardson and coworkers developed a simple scalable route towards ertugliflozin (80), a C-glycoside containing

Enantioselective synthesis of β-aryl-γ-lactam derivatives via Heck–Matsuda desymmetrization of N-protected 2,5-dihydro-1H-pyrroles

• Arnaldo G. de Oliveira Jr.,
• Martí F. Wang,
• Rafaela C. Carmona,
• Danilo M. Lustosa,
• Sergei A. Gorbatov and
• Carlos R. D. Correia

Beilstein J. Org. Chem. 2024, 20, 940–949, doi:10.3762/bjoc.20.84

• preclude chirality as in the transformation of a prochiral molecular entity into a chiral one [1]. It is a powerful and elegant strategy in asymmetric synthesis [2], which combined with the use of chiral ligands and transition-metal catalysts enabled many valuable transformations to increase molecular

Spatial arrangements of cyclodextrin host–guest complexes in solution studied by ¹³C NMR and molecular modelling

• Konstantin Lebedinskiy,
• Ivan Barvík,
• Zdeněk Tošner,
• Ivana Císařová,
• Jindřich Jindřich and
• Radim Hrdina

Beilstein J. Org. Chem. 2024, 20, 331–335, doi:10.3762/bjoc.20.33

• modelling and solid-state X-ray analysis, provides a detailed description of the spatial arrangement of cyclodextrin host–guest complexes in solution. The chiral cavity of the cyclodextrin molecule creates an anisotropic environment for the guest molecule resulting in a splitting of its prochiral carbon

• signals in 13C NMR spectra. This signal split can be correlated to the distance of the guest atoms from the wall of the host cavity and to the spatial separation of binding sites preferred by pairs of prochiral carbon atoms. These measurements complement traditional solid-state analyses, which rely on the

• anisotropy of the chiral cavity is expressed by differences in the magnetic shielding of prochiral atoms, resulting in signal splitting of the prochiral carbons of the guest molecule in 13C NMR spectra. Adamantan-2-amine hydrochloride was used as a model guest molecule containing three sets of prochiral

Application of N-heterocyclic carbene–Cu(I) complexes as catalysts in organic synthesis: a review

• Nosheen Beig,
• Varsha Goyal and
• Raj K. Bansal

Beilstein J. Org. Chem. 2023, 19, 1408–1442, doi:10.3762/bjoc.19.102

• compounds, including diaryl- and dialkyl ketones and prochiral ketones, respectively (Scheme 36) [50]. Riant, Leyssens and co-workers investigated the mechanism of the hydrosilylation reaction of ketones using DFT, in situ FTIR, NMR, and kinetic methods [51][52]. The catalytic characteristics of sterically

Enolates ambushed – asymmetric tandem conjugate addition and subsequent enolate trapping with conventional and less traditional electrophiles

• Péter Kisszékelyi and
• Radovan Šebesta

Beilstein J. Org. Chem. 2023, 19, 593–634, doi:10.3762/bjoc.19.44

• desymmetrization step during which the chiral enolate attacks (Si-face) the prochiral cyclohexadienone ring via a chair-like transition state. The reaction requires an excess amount of base, resulting in the formation of a more favorable lithium enolate. Subsequent oxidation of the boronates gave the corresponding

Synthetic study toward tridachiapyrone B

• Morgan Cormier,
• Florian Hernvann and
• Michaël De Paolis

Beilstein J. Org. Chem. 2022, 18, 1741–1748, doi:10.3762/bjoc.18.183

• yield was actually noted with (PhSe)2 as electrophile, 5 being obtained in 62% yield, enabling thus an evaluation of the next desymmetrization step. An overview of the scientific literature revealed that, while the asymmetric desymmetrization of prochiral 2,5-cyclohexadienones is a rich topic of

Synthesis of bis-spirocyclic derivatives of 3-azabicyclo[3.1.0]hexane via cyclopropene cycloadditions to the stable azomethine ylide derived from Ruhemann's purple

• Alexander S. Filatov,
• Olesya V. Khoroshilova,
• Anna G. Larina,
• Vitali M. Boitsov and
• Alexander V. Stepakov

Beilstein J. Org. Chem. 2022, 18, 769–780, doi:10.3762/bjoc.18.77

• prochiral cyclopropene 2j from the less sterically hindered side. This is consistent with previous experiments in which 3-substituted-1,2-diphenylcyclopropenes were utilized as dipolarophiles. Regretfully, neither methyl 1-methylcycloprop-2-enecarboxylate (2k) [37] nor 3-methyl-1,2,3-triphenylcycloprop-1

The asymmetric Henry reaction as synthetic tool for the preparation of the drugs linezolid and rivaroxaban

• Martin Vrbický,
• Karel Macek,
• Jaroslav Pochobradský,
• Jan Svoboda,
• Miloš Sedlák and
• Pavel Drabina

Beilstein J. Org. Chem. 2022, 18, 438–445, doi:10.3762/bjoc.18.46

• highly efficient catalysts based on copper complexes of different types of chiral ligands, 2-(pyridin-2-yl)imidazolidine-4-ones (I–III), bis-oxazolines (IV–VII), or diamine (VIII) were chosen for the study (Figure 2). Furthermore, the modification of the structure of the prochiral aldehyde intermediates

Recent advances in the asymmetric phosphoric acid-catalyzed synthesis of axially chiral compounds

• Alemayehu Gashaw Woldegiorgis and
• Xufeng Lin

Beilstein J. Org. Chem. 2021, 17, 2729–2764, doi:10.3762/bjoc.17.185

• bulky group into the ortho-position of prochiral 3,3’-bisindoles allowed the synthesis of new members of axially chiral biaryls (3,3’-bisindole derivatives) bearing both axial and central chirality in high yields and excellent stereoselectivities. Moreover, this methodology represents a new strategy for

• the catalytic enantioselective synthesis of axially chiral 3,3’-bisindole backbones from prochiral substrates [66]. The atroposelective synthesis of a new class of 3,3'-bisindoles 51 with axial and central chirality by dynamic kinetic resolution of 2-substituted 3,3'-bisindoles via asymmetric

α-Ketol and α-iminol rearrangements in synthetic organic and biosynthetic reactions

• Scott Benz and
• Andrew S. Murkin

Beilstein J. Org. Chem. 2021, 17, 2570–2584, doi:10.3762/bjoc.17.172

• catalyst in the presence of a substrate possessing a prochiral migrating group or (2) stereospecifically by means of a chiral α-ketol. As an example of an enantioselective rearrangement, complexes of nickel(II) with a series of chiral 1,2-diaminopropane or pyridineoxazoline ligands were evaluated for their

Kinetics of enzyme-catalysed desymmetrisation of prochiral substrates: product enantiomeric excess is not always constant

• Peter J. Halling

Beilstein J. Org. Chem. 2021, 17, 873–884, doi:10.3762/bjoc.17.73

• Peter J. Halling WestCHEM, Dept Pure & Applied Chemistry, University of Strathclyde, Glasgow G1 1XL, Scotland, UK 10.3762/bjoc.17.73 Abstract The kinetics of enzymatic desymmetrisation were analysed for the most common kinetic mechanisms: ternary complex ordered (prochiral ketone reduction); ping

• -pong second (ketone amination, diol esterification, desymmetrisation in the second half reaction); ping-pong first (diol ester hydrolysis) and ping-pong both (prochiral diacids). For plausible values of enzyme kinetic parameters, the product enantiomeric excess (ee) can decline substantially as the

• study if and how the product ee declines at high conversion. Keywords: enantiomeric excess; enzyme; kinetic mechanisms; kinetic parameters; prochiral; Introduction There is great interest in using enzymatic catalysis in the synthesis of homochiral molecules. An early approach was to use

α,γ-Dioxygenated amides via tandem Brook rearrangement/radical oxygenation reactions and their application to syntheses of γ-lactams

• Mikhail K. Klychnikov,
• Radek Pohl,
• Ivana Císařová and
• Ullrich Jahn

Beilstein J. Org. Chem. 2021, 17, 688–704, doi:10.3762/bjoc.17.58

• cyclized diastereomeric radicals trans-22m,n and two radicals cis-22m,n result, which differ in their orientation with respect to the racemic silyloxy group (cf. Scheme 9). The situation in the azaspiro[4,4] and azaspiro[4][5] radicals 22m,n is, however, more complex since they are prochiral, and thus

The preparation and properties of 1,1-difluorocyclopropane derivatives

• Kymbat S. Adekenova,
• Peter B. Wyatt and
• Sergazy M. Adekenov

Beilstein J. Org. Chem. 2021, 17, 245–272, doi:10.3762/bjoc.17.25

• enantioselective functional group interconversions on prochiral or racemic difluorocyclopropane and difluorocyclopropene derivatives have provided important ways of obtaining enantiomerically pure cyclopropanes. The key reactions in this context are the enzyme-catalyzed formation and hydrolysis of esters and the

• hydrogenation of difluorocyclopropenes [73][79]. Enzymatic hydrolysis or esterification: The first example of the enzymatic resolution of gem-difluorocyclopropanes was reported by Itoh et al. [80]. The prochiral diacetate of cis-1,2-bis-(hydroxymethyl)-3,3-difluorocyclopropane was converted into the

• [81]. The authors obtained the chiral monoacetate intermediates (R)-78 and (S)-80 by lipase-catalyzed methods. The lipase-catalyzed asymmetric transesterification of prochiral diol 77 and the deacetylation of the prochiral diacetate 79 resulted in the formation of the (R)-monoacetate (R)-78 and (S

Insight into functionalized-macrocycles-guided supramolecular photocatalysis

• Minzan Zuo,
• Krishnasamy Velmurugan,
• Kaiya Wang,
• Xueqi Tian and
• Xiao-Yu Hu

Beilstein J. Org. Chem. 2021, 17, 139–155, doi:10.3762/bjoc.17.15

• photochemical reactions, including photoisomerization, photocyclodimerization, and H2 evolution [7][23]. Chirality induction in a prochiral guest via photochemical reactions is a delightful approach. This can not only transfer the chirality of the host cavity to the molecular photoproduct via excited-state

Ring-closing metathesis of prochiral oxaenediynes to racemic 4-alkenyl-2-alkynyl-3,6-dihydro-2H-pyrans

• Viola Kolaříková,
• Markéta Rybáčková,
• Martin Svoboda and
• Jaroslav Kvíčala

Beilstein J. Org. Chem. 2020, 16, 2757–2768, doi:10.3762/bjoc.16.226

• ., Flemingovo nám. 2, 166 10 Prague 6, Czech Republic 10.3762/bjoc.16.226 Abstract The prochiral 4-(allyloxy)hepta-1,6-diynes, optionally modified in the positions 1 and 7 with an alkyl or ester group, undergo a chemoselective ring-closing enyne metathesis yielding racemic 4-alkenyl-2-alkynyl-3,6-dihydro-2H

• for other catalytic reactions, e.g., for the Pauson–Khand reaction [14]. In the enantioselective RCM, prochiral trienes have been most often employed, leading to chiral cycloalkenes. The Schrock molybdenum precatalysts [15][16][17] proved to be more effective than the Grubbs or Collins ruthenium

• significantly more demanding strategy uses prochiral substrates and chiral metathesis precatalysts. Despite many examples of enantioselective RCM, only two examples of an enantioselective RCEYM have been reported (both featuring a dienyne substrate and a Schrock complex) [21][30], no enantioselective enediyne

Water-soluble host–guest complexes between fullerenes and a sugar-functionalized tribenzotriquinacene assembling to microspheres

• Si-Yuan Liu,
• Xin-Rui Wang,
• Man-Ping Li,
• Wen-Rong Xu and
• Dietmar Kuck

Beilstein J. Org. Chem. 2020, 16, 2551–2561, doi:10.3762/bjoc.16.207

• is clearly a consequence of the prochiral nature of the TBTQ core. We also note that such splitting phenomenon was reported for neither six-fold sugar-functionalized cyclotriveratrylenes [41], which are directly comparable to TBTQ-(OAcG)6, nor for six-fold sugar-functionalized triptycene [42], and

• of three magnetically equivalent tentacles at the rigid, prochiral TBTQ skeleton. The mass spectrometric characterization of TBTQ-(OAcG)6 turned out to be quite difficult. The MALDI-(+) mass spectrum (see Figure S10 and Table S1 in Supporting Information File 1), recorded with α-cyano-4

Hierarchically assembled helicates as reaction platform – from stoichiometric Diels–Alder reactions to enamine catalysis

• David Van Craen,
• Jenny Begall,
• Johannes Großkurth,
• Leonard Himmel,
• Oliver Linnenberg,
• Elisabeth Isaak and
• Markus Albrecht

Beilstein J. Org. Chem. 2020, 16, 2338–2345, doi:10.3762/bjoc.16.195

• processes based on the principle to use self-assembled coordination platforms (or as in the present case mixtures thereof) to control stereoselective C–C bond-forming reactions. Stereoinduction usually relies on spatial proximity of the prochiral carbon atoms and a chiral information of, e.g., a chiral

NHC-catalyzed enantioselective synthesis of β-trifluoromethyl-β-hydroxyamides

• Alyn T. Davies,
• Mark D. Greenhalgh,
• Alexandra M. Z. Slawin and
• Andrew D. Smith

Beilstein J. Org. Chem. 2020, 16, 1572–1578, doi:10.3762/bjoc.16.129

• stereogenic trifluoromethyl centers is through enantioselective addition of enolates or their equivalents to prochiral trifluoromethyl ketones (Figure 1A). Within this area, a common catalytic approach has utilized aliphatic ketones as enolate equivalents using prolinamide, cinchona, or hybrid catalysts that

A review of asymmetric synthetic organic electrochemistry and electrocatalysis: concepts, applications, recent developments and future directions

• Munmun Ghosh,
• Valmik S. Shinde and
• Magnus Rueping

Beilstein J. Org. Chem. 2019, 15, 2710–2746, doi:10.3762/bjoc.15.264

• of a poly-ʟ-valine 6 coated graphite cathode for asymmetric electrochemical reductions in two consecutive reports. In the first communication, they carried out the asymmetric reduction of prochiral activated olefins 5 and 8, affording 7 and 9 with optical yields of 25% and 43%, respectively (Scheme 3

• ) [23]. In the second report, the same electrode was applied for the asymmetric reduction of prochiral carbonyl compounds 10a and 12a, oximes 14 and gem-dibromo compounds 16 (Scheme 4). Among all of these the highest optical yield (16.6%) was obtained in the reduction of gem-dibromide substrates 16 to

• catalyze the enantioselective hydrogenation of prochiral ketones 18. The prochiral ketones such as acetophenone, 1-tetralone and 1-indanone were reduced to their corresponding alcohols 20a, 20b and 20c, respectively, with moderate optical yields, with formation of (S) as major enantiomer (Scheme 5). After

Chiral terpene auxiliaries V: Synthesis of new chiral γ-hydroxyphosphine oxides derived from α-pinene

• Anna Kmieciak and
• Marek P. Krzemiński

Beilstein J. Org. Chem. 2019, 15, 2493–2499, doi:10.3762/bjoc.15.242

• ligands that were obtained from readily available natural (1S)-β-pinene and (1S)-α-pinene [18]. We applied these ligands for the formation of the ruthenium complexes, which were successfully used as catalysts in asymmetric transfer hydrogenation of prochiral ketones. In continuation of our studies on the

Self-assembled coordination thioether silver(I) macrocyclic complexes for homogeneous catalysis

• Zhen Cao,
• Aline Lacoudre,
• Cybille Rossy and
• Brigitte Bibal

Beilstein J. Org. Chem. 2019, 15, 2465–2472, doi:10.3762/bjoc.15.239

• . These silver(I) complexes adopted similar structures in solution and in the solid state. As each sulfur atom in the ligand is prochiral, macrocycles L2M2 were obtained as mixtures of diastereoisomers, depending on the configurations of the sulfur atoms coordinated to silver cations. The X-ray structures

• ; homogeneous catalysis; prochiral; silver complex; thioether ligand; Introduction Since the early advances in the late eighties [1][2][3][4][5][6][7][8][9][10], silver(I) catalysis has been widely exploited based on the versatile redox and soft Lewis acid properties of this coinage metal cation. Silver

• prochiral sulfur atom of the ligand becomes asymmetric by coordination to silver(I). In absence of any chiral source, the complexes were obtained either as nonchiral coordination products with a center or an axis of symmetry (1a and 1c, with (R,S)–1 ligands) or as a racemic mixture (1d, with (R,R)–1 or (S,S

Asymmetric synthesis of a high added value chiral amine using immobilized ω-transaminases

• Antonella Petri,
• Valeria Colonna and
• Oreste Piccolo

Beilstein J. Org. Chem. 2019, 15, 60–66, doi:10.3762/bjoc.15.6

• prochiral precursor 1-Boc-3-piperidone using immobilized ω-transaminases (TAs-IMB), isopropylamine as amine donor and pyridoxal-5’-phosphate (PLP) as cofactor is described. Compared to other methods, the present approach affords the target compound in just one step with high yield and high enantiomeric

• by using resolution of racemic mixtures, preparation from chiral precursors or asymmetric synthesis from prochiral compounds [20][21][22]. In contrast, only few examples have been published on the synthesis of this molecule through biotransformations [23][24]. In these procedures TAs are used in

Ruthenium-based olefin metathesis catalysts with monodentate unsymmetrical NHC ligands

• Veronica Paradiso,
• Chiara Costabile and
• Fabia Grisi

Beilstein J. Org. Chem. 2018, 14, 3122–3149, doi:10.3762/bjoc.14.292

•  31). The catalytic performances of 164 were tested in the asymmetric ring-closing metathesis (ARCM) of prochiral trienes 166, 168 and 170 (Scheme 15, Table 6) [52][54] achieving enantiomeric excesses (ee) that were generally lower with respect to those obtained with the C2-symmetrical analogue 165