Comparative analysis of complanadine A total syntheses

• Reem Al-Ahmad and
• Mingji Dai

Beilstein J. Org. Chem. 2025, 21, 2334–2344, doi:10.3762/bjoc.21.178

• with MeI in presence of benzyltrimethylammonium fluoride (BTAF). At this stage, to prepare optically active natural product, the racemic mixture of 51 was separated using chiral HPLC to afford (+)-51 and (−)-51, which were used to prepare both enantiomers of complanadine A for biological evaluations

A chiral LC–MS strategy for stereochemical assignment of natural products sharing a 3-methylpent-4-en-2-ol moiety in their terminal structures

• Rei Suo,
• Raku Irie,
• Hinako Nakayama,
• Yuta Ishimaru,
• Yuya Akama,
• Masato Oikawa and
• Shiro Itoi

Beilstein J. Org. Chem. 2025, 21, 2243–2249, doi:10.3762/bjoc.21.171

• chiral HPLC columns and with various elution profiles, the four stereoisomers of 6 were successfully separated on a CHIRALPAK ID-3 column at 40 °C with aqueous MeOH gradient elution (Figure S3, Supporting Information File 1). The developed method for absolute configuration assignment of MPO was applied

• followed by ozonolysis to generate 3-((4-bromobenzoyl)oxy)-2-methylbutanoic acid. The four stereoisomers of this fragment were prepared through two separate Evans aldol reactions, each affording a pair of diastereomers. The final four stereoisomers were resolved by chiral HPLC (CHIRALPAK IA column with

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

• yields (ΦF up to 0.69). Furthermore, enantiomeric resolution of inherent chiral MC1 was achieved using preparative chiral HPLC, enabling detailed investigation of its chiroptical behavior through circular dichroism and circularly polarized luminescence spectroscopy. Keywords: dihydroindolocarbazole

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

• 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

Synthesis of optically active folded cyclic dimers and trimers

• Ena Kumamoto,
• Kana Ogawa,
• Kazunori Okamoto and
• Yasuhiro Morisaki

Beilstein J. Org. Chem. 2025, 21, 1603–1612, doi:10.3762/bjoc.21.124

• , respectively. Dimer (Sp)-6 (6.8 mg, 0.0062 mmol, 16%) was isolated from the first fraction by recyclable HPLC (CH2Cl2 as an eluent) as a light yellow solid. Trimer (Sp)-7 was isolated from the second fraction by recyclable HPLC (CH2Cl2 as an eluent). Further purification of (Sp)-7 was carried out using chiral

• HPLC (CH2Cl2/hexane = 5:5 v/v as an eluent) to obtain (Sp)-7 (2.0 mg, 0.0012 mmol, 3%) as a yellow solid. Enantiomers were obtained by the same procedure from (Rp)-4. (Sp)-6. Rf = 0.40 (hexane/ethyl acetate = 4:1 v/v). 1H NMR (CDCl3, 500 MHz) δ 3.12 (m, 8H), 3.46 (m, 4H), 3.60 (m, 4H), 7.23 (s, 8H

pH-Controlled isomerization kinetics of ortho-disubstituted benzamidines: E/Z isomerism and axial chirality

• Ryota Kimura,
• Satoshi Ichikawa and
• Akira Katsuyama

Beilstein J. Org. Chem. 2025, 21, 1568–1576, doi:10.3762/bjoc.21.120

• 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

• peaks corresponding to the atropisomers arising from the C–C axis. Each atropisomer could be separated by chiral HPLC, and the isomer eluting earlier was used for the following kinetic analysis. The effect of pH on the kinetics of the racemization was investigated. The isomer was heated in the buffer

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

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

• excesses were determined using chiral HPLC analysis using an Agilent 1260 LC instrument (Santa Clara, CA, USA) with Daicel Chiralcel AD-H column (Hyderabad, India) with a mixture of isopropyl alcohol and hexane as eluents. All liquid aldehydes were washed with saturated aqueous sodium bicarbonate solution

• afford the pure product 3. The enantiomeric excess was determined using chiral HPLC analysis with a mixture of iPrOH and hexane as eluent. Oxazolidine-containing bioactive compounds. Asymmetric catalytic synthetic methods of oxazolidine derivatives. Scope of aziridines and aldehydes. Proposed reaction

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

• detector and found that the C(aryl)–N(amide) bond axial chirality exists in amide compound 7. We attempted the optical resolution of racemic compound (±)-7 and obtained (+)-7 and (−)-7 using a semi-preparative chiral HPLC on 50 milligram scales. We also investigated the racemization process associated with

• steps from phosphine oxide 8. Chiral HPLC analysis confirmed its axial chirality at the C(aryl)–N(amide) bond. The optical resolution of (±)-7 yielded (+)-7 and (−)-7. The racemization barrier of (−)-7 in n-dodecane was determined to be 25.0 kcal/mol at 25 °C, with a half-life of approximately 1.3 days

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

• –240 mesh). Chiral HPLC analysis was performed using different chiral columns. IR spectra were recorded on an FTIR instrument. High-resolution mass spectra were performed by positive electrospray ionization using a quadrupole-time-of-flight detector (ESI+-Q-TOF) instrument. All compounds were purchased

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

• 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

Asymmetric organocatalytic synthesis of chiral homoallylic amines

• Nikolay S. Kondratyev and
• Andrei V. Malkov

Beilstein J. Org. Chem. 2024, 20, 2349–2377, doi:10.3762/bjoc.20.201

• separate peaks on chiral HPLC. Kinetic resolution of chiral secondary allylboronates [15][30]. (E)-Stereospecific asymmetric α-trifluoromethylallylation of cyclic imines and hydrazones [31]. Hosomi–Sakurai-type allylation of in situ-formed N-Fmoc aldimines [32]. Chiral squaramide-catalysed hydrogen bond

Natural resorcylic lactones derived from alternariol

• Joachim Podlech

Beilstein J. Org. Chem. 2024, 20, 2171–2207, doi:10.3762/bjoc.20.187

Direct synthesis of acyl fluorides from carboxylic acids using benzothiazolium reagents

• Lilian M. Maas,
• Alex Haswell,
• Rory Hughes and
• Matthew N. Hopkinson

Beilstein J. Org. Chem. 2024, 20, 921–930, doi:10.3762/bjoc.20.82

• observed (yield = 72%) with analysis by chiral HPLC revealing no erosion of the enantiomeric ratio (er = 99:1). At this stage, the suitability of BT-SCF3-mediated deoxyfluorination for the one-pot formation of peptide linkages between amino acids was investigated (Scheme 3). Treatment of N-Boc-valine under

• Campbell (Newcastle University) for assistance with chiral HPLC measurements. Funding This work is funded by the Friedrich Ebert Stiftung (scholarship to L.M.M.) and the School of Natural and Environmental Sciences at Newcastle University (studentship to A.H.). Financial support from Deutsche

Switchable molecular tweezers: design and applications

• Pablo Msellem,
• Maksym Dekthiarenko,
• Nihal Hadj Seyd and
• Guillaume Vives

Beilstein J. Org. Chem. 2024, 20, 504–539, doi:10.3762/bjoc.20.45

• enantiomers (P,P) and (M,M) were separated by chiral HPLC and displayed opposite circularly polarized luminescence (CPL) and electronic circular dichroism (ECD) properties. The addition of ZnCl2 switched the system from a compact conformation to an extended conformation, resulting in a modulation of the

Chiral phosphoric acid-catalyzed transfer hydrogenation of 3,3-difluoro-3H-indoles

• Yumei Wang,
• Guangzhu Wang,
• Yanping Zhu and
• Kaiwu Dong

Beilstein J. Org. Chem. 2024, 20, 205–211, doi:10.3762/bjoc.20.20

• spectroscopy and the ee values were determined by chiral HPLC. Structures of bioactive fluorinated indole derivatives. Proposed mechanism for the transfer hydrogenation reaction. Synthesis of chiral indolines via asymmetric reduction. Substrate scope of 3,3-difluoro-3H-indoles. Experiment at 2 mmol scale

Perspectives on push–pull chromophores derived from click-type [2 + 2] cycloaddition–retroelectrocyclization reactions of electron-rich alkynes and electron-deficient alkenes

• Michio Yamada

Beilstein J. Org. Chem. 2024, 20, 125–154, doi:10.3762/bjoc.20.13

• when the TCBD moiety was incorporated at the axial position of the subphthalocyanine (SubPc) core (Figure 3) [131]. Axially chiral SubPc–TCBD–aniline conjugates 59 and 60 were characterized via optical-resolution analysis through chiral HPLC using a Chiralpak IC column. The researchers unequivocally

• types of subporphyrin derivatives 61 and 62, wherein the subporphyrin skeleton was functionalized at its meso or axial position with the TCBD moiety (Figure 3). Although the optical resolution of 61 failed, they succeeded in achieving the optical resolution of 62 via chiral HPLC using a Chiralpak IC

A novel recyclable organocatalyst for the gram-scale enantioselective synthesis of (S)-baclofen

• Gyula Dargó,
• Dóra Erdélyi,
• Balázs Molnár,
• Péter Kisszékelyi,
• Zsófia Garádi and
• József Kupai

Beilstein J. Org. Chem. 2023, 19, 1811–1824, doi:10.3762/bjoc.19.133

• . Further details are available in Supporting Information File 1. The enantiomeric ratios of the samples were determined by chiral high-performance liquid chromatography (HPLC) measurements. The exact conditions of chiral HPLC are indicated in the experimental section of the corresponding compound

• the cyclohexyl derivative of Meldrum’s acid 15 to 4-chloro-trans-β-nitrostyrene (16).a Supporting Information Supporting Information File 28: Experimental part, NMR, IR, and chiral HPLC spectra. Acknowledgements The authors are grateful to Péter Bagi for his help with the chiral HPLC measurements

Acetaldehyde in the Enders triple cascade reaction via acetaldehyde dimethyl acetal

• Alessandro Brusa,
• Debora Iapadre,
• Maria Edith Casacchia,
• Alessio Carioscia,
• Giuliana Giorgianni,
• Giandomenico Magagnano,
• Fabio Pesciaioli and
• Armando Carlone

Beilstein J. Org. Chem. 2023, 19, 1243–1250, doi:10.3762/bjoc.19.92

• %) were added to a solution of 1 (10 mol %) in 2 mL of solvent (0.25 M) and allowed to stir for 48 hours at room temperature. Yields of isolated compounds are given. Diastereomeric ratio (dr) determined by 1H NMR analysis. Enatiomeric excess (ee) determined by chiral HPLC analysis. Original triple

Construction of hexabenzocoronene-based chiral nanographenes

• Ranran Li,
• Di Wang,
• Shengtao Li and
• Peng An

Beilstein J. Org. Chem. 2023, 19, 736–751, doi:10.3762/bjoc.19.54

• determined for the enantiopure helicenes. For compound 12, the racemization barrier was 24.8 kcal mol−1 at 298 K, which provides a racemization half-life (t1/2) of 24.4 h. For compounds 11 and 13, neither racemization nor decomposition was observed by chiral HPLC after heating hexadecane solutions of each

• through oxidative cyclodehydrogenation and imine formation in a 72% yield. It was noted that no other regioisomer was detected for the asymmetrical precursor 30. The pair of enantiomers was confirmed by the racemic structure's single-crystal X-ray diffractometry and separated by chiral HPLC, and no

• structures were confirmed by single-crystal X-ray diffractometry and chiral HPLC. The rotational isomerization barrier of C6F4 ring for the analogue of 62, with two tert-butyl groups substituted by protons was determined as 24.6 kcal/mol at 40 °C with a half-life of t1/2 = 107 min. Employing the similar

A new oxidatively stable ligand for the chiral functionalization of amino acids in Ni(II)–Schiff base complexes

• Alena V. Dmitrieva,
• Oleg A. Levitskiy,
• Yuri K. Grishin and
• Tatiana V. Magdesieva

Beilstein J. Org. Chem. 2023, 19, 566–574, doi:10.3762/bjoc.19.41

• Information File 24: Experimental details, characterization, and copies of spectra. Acknowledgements Prof. Dr. Denis Chusov is acknowledged for chiral HPLC analyses performed in the A.N. Nesmeyanov Institute of Organoelement Compounds of RAS. Funding This work was supported by the Russian Foundation for

An accelerated Rauhut–Currier dimerization enabled the synthesis of (±)-incarvilleatone and anticancer studies

• Tharun K. Kotammagari,
• Sweta Misra,
• Sayantan Paul,
• Sunita Kunte,
• Rajesh G. Gonnade,
• Manas K. Santra and
• Asish K. Bhattacharya

Beilstein J. Org. Chem. 2023, 19, 204–211, doi:10.3762/bjoc.19.19

• The total synthesis of racemic incarvilleatone has been achieved by utilizing unexplored accelerated Rauhut–Currier (RC) dimerization. The other key steps of the synthesis are oxa-Michael and aldol reactions in a tandem sequence. Racemic incarvilleatone was separated by chiral HPLC and the

• Incarvillea younghusbandii (Figure 1). This plant is used in Chinese folk medicine to treat dizziness and anemia [1]. Zhang and co-workers [1] separated the racemic incarvilleatone in two individual enantiomers, (−)-incarvilleatone [(−)-1] and (+)-incarvilleatone [(+)-1] by performing chiral HPLC. The

Enantioselective total synthesis of putative dihydrorosefuran, a monoterpene with an unique 2,5-dihydrofuran structure

• Irene Torres-García,
• Josefa L. López-Martínez,
• Rocío López-Domene,
• Manuel Muñoz-Dorado,
• Ignacio Rodríguez-García and
• Miriam Álvarez-Corral

Beilstein J. Org. Chem. 2022, 18, 1264–1269, doi:10.3762/bjoc.18.132

• stereoselective kinetic resolution of allenol 3 via lipase AK-catalyzed acetylation [15]. In this way, unaltered, (−)-hydroxyallene 3 could be separated from (+)-acetyl derivative 9 through standard column chromatography (Scheme 3). Enantiomeric excesses of (−)-3 and (+)-9 were determined by chiral HPLC analyses

A Streptomyces P450 enzyme dimerizes isoflavones from plants

• Run-Zhou Liu,
• Shanchong Chen and
• Lihan Zhang

Beilstein J. Org. Chem. 2022, 18, 1107–1115, doi:10.3762/bjoc.18.113

• and 2 with respect to atropisomerism was assessed by chiral HPLC analysis and the comparison of experimental and calculated ECD spectra. While 1 showed a ≈3:1 atropisomer ratio, with the M-atropisomer being the major form, 2 did not exhibit a Cotton effect in the ECD measurement, suggesting that it is

Anti-inflammatory aromadendrane- and cadinane-type sesquiterpenoids from the South China Sea sponge Acanthella cavernosa

• Shou-Mao Shen,
• Qing Yang,
• Yi Zang,
• Jia Li,
• Xueting Liu and
• Yue-Wei Guo

Beilstein J. Org. Chem. 2022, 18, 916–925, doi:10.3762/bjoc.18.91

• equipped with a DAD G1315D detector and an Agilent Eclipse XDB-C18 column (5 μm, 9.4 × 250 mm). In contrast, chiral HPLC separation was operated on the chromatography equipped with CHIRALPAK IB N-3 column (5 μm, 4.6 × 250 mm). All solvents used for CC and HPLC were analytical grade (Shanghai Chemical

• successively separated by Sephadex LH-20 CC (PE/CH2Cl2/MeOH, 2:1:1) and RP-HPLC (55% MeCN in H2O, 3.0 mL/min) to afford compound 6 (1.3 mg, tR = 12.4 min). The separation of racemic mixtures (4 and 5) was performed on chiral HPLC equipped with a CHIRALPAK IB N-3 column eluted with MeCN/H2O [4: 25:75, 5: 15:85