Molbank

9 pages, 1055 KiB

Open AccessShort Note

A Pyrene-Anchored Nickel N-Heterocyclic Carbene–Isoquinoline Complex Promotes CO₂ Reduction

by Xue Chen, Li-Li Yu, Shu-Ying Chen, Tong Wang and Quan Zhou

Molbank 2025, 2025(3), M2035; https://doi.org/10.3390/M2035 - 8 Jul 2025

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In this study, on the basis of a previous report, a pyrene-anchored nickel complex was designed and synthesized via five steps. The NMR spectra of the synthesized complex were found to exhibit significant proton and carbon chemical shift anisotropy. Cyclic voltammetry spectra showed [...] Read more.

In this study, on the basis of a previous report, a pyrene-anchored nickel complex was designed and synthesized via five steps. The NMR spectra of the synthesized complex were found to exhibit significant proton and carbon chemical shift anisotropy. Cyclic voltammetry spectra showed that the introduction of pyrene slightly influenced the onset potential of CO₂ reduction. Lastly, controlled-potential electrolysis experiments disclosed that a pyrene-anchored nickel carbene–isoquinoline (Ni−2) complex selectively converted CO₂ into CH₄ with a TON value of 2.3 h⁻¹. Full article

(This article belongs to the Topic Heterocyclic Carbene Catalysis)

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5 pages, 302 KiB

Open AccessShort Note

(5R,7R,11bR)-9-(di(1H-Indol-3-yl)methyl)-4,4,7,11b-tetramethyl-1,2,3,4,4a,5,6,6a,7,11,11a,11b-dodecahydrophenanthro[3,2-b]furan-5-yl Acetate

by Jessica A. Perez-Rangel, Gabriela Servín-García, Atilano Gutiérrez-Carrillo, Alejandro Islas-Jácome, Luis Chacón-García, Rosa E. del Río and Carlos J. Cortés-García

Molbank 2025, 2025(3), M2034; https://doi.org/10.3390/M2034 - 7 Jul 2025

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Abstract

The semi-synthesis of the (5R,7R,11bR)-9-(di(1H-indol-3-yl)methyl)-4,4,7,11b-tetramethyl-1,2,3,4,4a,5,6,6a,7,11,11a,11b-dodecahydrophenanthro[3,2-b]furan-5-yl acetate was performed via a pseudo-multicomponent reaction involving a double Friedel–Crafts alkylation between the natural product-derived aldehyde 6β-acetoxyvouacapane and the corresponding indole. The transformation was carried [...] Read more.

The semi-synthesis of the (5R,7R,11bR)-9-(di(1H-indol-3-yl)methyl)-4,4,7,11b-tetramethyl-1,2,3,4,4a,5,6,6a,7,11,11a,11b-dodecahydrophenanthro[3,2-b]furan-5-yl acetate was performed via a pseudo-multicomponent reaction involving a double Friedel–Crafts alkylation between the natural product-derived aldehyde 6β-acetoxyvouacapane and the corresponding indole. The transformation was carried out under solvent-free mechanochemical conditions using mortar and pestle grinding, with ZnCl₂ as the catalyst. Structural elucidation of the target compound was accomplished using 1D and 2D NMR spectroscopy (¹H, ¹³C, COSY, HSQC, and HMBC), FT-IR, and high-resolution mass spectrometry (HRMS). Full article

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7 pages, 1961 KiB

Open AccessShort Note

3′H-Spiro[dibenzo[c,h]xanthene-7,1′-isobenzofuran]-3′-one

by Brian A. Chalmers, David B. Cordes, Aidan P. McKay, Iain L. J. Patterson, Nadiia Vladymyrova and Iain A. Smellie

Molbank 2025, 2025(3), M2033; https://doi.org/10.3390/M2033 - 7 Jul 2025

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Abstract

Target compound 3′H-spiro[dibenzo[c,h]xanthene-7,1′-isobenzofuran]-3′-one (1) has long been known to be a by-product obtained from the preparation of naphtholphthalein. The structure of compound 1 was elucidated in the early 20th century; however, this compound has not [...] Read more.

Target compound 3′H-spiro[dibenzo[c,h]xanthene-7,1′-isobenzofuran]-3′-one (1) has long been known to be a by-product obtained from the preparation of naphtholphthalein. The structure of compound 1 was elucidated in the early 20th century; however, this compound has not previously been fully characterized using modern techniques. In this report, ¹H NMR and ¹³C NMR spectra are provided. X-ray crystallography is also used to characterize the title compound for the first time. Full article

(This article belongs to the Section Structure Determination)

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9 pages, 2968 KiB

Open AccessShort Note

Diethyl 3-(4-Bromobenzoyl)-7-(4-pyridyl)indolizine-1,2-dicarboxylate

by Mihaela Cristea, Mihai Răducă, Maria Gdaniec, Sergiu Shova, Nicoleta Doriana Banu and Florea Dumitrascu

Molbank 2025, 2025(3), M2032; https://doi.org/10.3390/M2032 - 7 Jul 2025

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Abstract

The title compound, C₂₆H₂₁BrN₂O₅ (Compound 4), was obtained via our previously described procedure with modifications, i.e., via a facile one-pot three component reaction starting from commercially available materials. Compound 4 was crystallized from nitromethane. It [...] Read more.

The title compound, C₂₆H₂₁BrN₂O₅ (Compound 4), was obtained via our previously described procedure with modifications, i.e., via a facile one-pot three component reaction starting from commercially available materials. Compound 4 was crystallized from nitromethane. It crystalized in a triclinic crystal system, in the P-

\bar{1}

space group. The crystal structure of 4 is described herein. Hirsfeld surface analysis, generated by the Crystal Explorer 21 software, was used to visualize the intermolecular close contacts in the title compound. The electrostatic, dispersion, and total energies in the crystal structure were calculated using the same program. Full article

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10 pages, 1171 KiB

Open AccessShort Note

N,N,N′-Tris(trimethylsilyl)-2-pyridinecarboximidamide

by Mukaila A. Ibrahim, Kathryn E. Preuss and René T. Boeré

Molbank 2025, 2025(3), M2031; https://doi.org/10.3390/M2031 - 3 Jul 2025

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Abstract

N,N,N′-tris(trimethylsilyl)-carboximidamides are effective reagents in synthetic chemistry in reactions with both non-metal and metal halides, because the side product is the mild and volatile ClSi(CH₃)₃ rather than corrosive HCl. The title compound inserts the 2-pyridylamidinate [...] Read more.

N,N,N′-tris(trimethylsilyl)-carboximidamides are effective reagents in synthetic chemistry in reactions with both non-metal and metal halides, because the side product is the mild and volatile ClSi(CH₃)₃ rather than corrosive HCl. The title compound inserts the 2-pyridylamidinate fragment into several non-metal systems, including custom chelating radical ligands. The single-crystal X-ray diffraction structure was determined and modeled by Hirshfeld atom refinement using custom aspherical atomic scattering factors. Excellent data quality led to a model with enhanced precision of all interatomic distances and free refinement of H-atom positions and anisotropic displacement ellipsoids. This structure model is compared to the four previously published analogous structures. Full article

(This article belongs to the Section Structure Determination)

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4 pages, 265 KiB

Open AccessShort Note

[1,2,5]Thiadiazolo[3,4-b]pyrazine-5,6(4H,7H)-dione

by Lidia S. Konstantinova, Natalia V. Obruchnikova and Oleg A. Rakitin

Molbank 2025, 2025(3), M2030; https://doi.org/10.3390/M2030 - 1 Jul 2025

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Abstract

Fused 1,2,5-chalcogenadiazoles are often used as biologically active compounds and organic optovoltaic materials. [1,2,5]Thiadiazolo[3,4-b]pyrazines are much less studied due to difficulties in their preparation. In this communication, [1,2,5]thiadiazolo[3,4-b]pyrazine-5,6(4H,7H)-dione, a key precursor for the synthesis of [...] Read more.

Fused 1,2,5-chalcogenadiazoles are often used as biologically active compounds and organic optovoltaic materials. [1,2,5]Thiadiazolo[3,4-b]pyrazines are much less studied due to difficulties in their preparation. In this communication, [1,2,5]thiadiazolo[3,4-b]pyrazine-5,6(4H,7H)-dione, a key precursor for the synthesis of 5,6-dihalo-[1,2,5]thiadiazolo[3,4-b]pyrazines, was prepared via condensation of 1,2,5-thiadiazole-3,4-diamine with oxalic acid or oxalyl chloride. The structure of the newly synthesized compound was established by elemental analysis, high-resolution mass spectrometry, ¹H and ¹³C NMR, IR spectroscopy, and mass spectrometry. Full article

(This article belongs to the Collection Heterocycle Reactions)

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Scheme 1

10 pages, 1743 KiB

Open AccessShort Note

4-(4-Formyl-3,5-dimethoxyphenoxy)butyric Acid (BAL)

by Alex Lovstedt, Tracy R. Thompson and George Barany

Molbank 2025, 2025(3), M2029; https://doi.org/10.3390/M2029 - 26 Jun 2025

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Abstract

The title compound, 4-(4-formyl-3,5-dimethoxyphenoxy)butyric acid (BAL), is an important “handle” for solid-phase synthesis of peptides and related compounds. Reported here is an X-ray single crystal structural analysis of BAL. The molecule is almost entirely flat, and the crystal is held together by π-stacking [...] Read more.

The title compound, 4-(4-formyl-3,5-dimethoxyphenoxy)butyric acid (BAL), is an important “handle” for solid-phase synthesis of peptides and related compounds. Reported here is an X-ray single crystal structural analysis of BAL. The molecule is almost entirely flat, and the crystal is held together by π-stacking and hydrogen bonding. Full article

(This article belongs to the Section Structure Determination)

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7 pages, 1118 KiB

Open AccessShort Note

4-([1,1′:3′,1′′-terphenyl]-2′-yloxy)-5-chlorophthalonitrile

by Dmitry Erzunov, Vyacheslav Baklagin, Igor Abramov, Vladimir Maizlish, Roman Rumyantsev and Arthur Vashurin

Molbank 2025, 2025(3), M2028; https://doi.org/10.3390/M2028 - 24 Jun 2025

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Abstract

The study focuses on the synthesis and detailed crystal structure analysis of 4-([1,1′:3′,1′′-terphenyl]-2′-yloxy)-5-chlorophthalonitrile. Using X-ray diffraction methods, the authors achieved the precise refinement of the atomic arrangement, revealing the specific spatial organization of molecules within the crystal lattice. The manuscript thoroughly discusses the [...] Read more.

The study focuses on the synthesis and detailed crystal structure analysis of 4-([1,1′:3′,1′′-terphenyl]-2′-yloxy)-5-chlorophthalonitrile. Using X-ray diffraction methods, the authors achieved the precise refinement of the atomic arrangement, revealing the specific spatial organization of molecules within the crystal lattice. The manuscript thoroughly discusses the key intermolecular interactions—such as hydrogen bonding and π-π stacking—that govern the crystal packing. These interactions play a crucial role in stabilizing the structure and have a direct impact on the material’s physical and chemical properties, including its thermal stability and optical characteristics. Full article

(This article belongs to the Section Structure Determination)

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10 pages, 4166 KiB

Open AccessCommunication

The Absolute Configuration Determination of Patagonic Acid

by Eva E. Soto-Guzmán, Hilda J. Pagaza-Ibarra, Antonio J. Oliveros-Ortiz, Gabriela Rodríguez-García, Yliana López, Brenda Y. Bedolla-García, Carlos M. Cerda-García-Rojas, Christine Thomassigny, Mario A. Gómez-Hurtado, Armando Talavera-Alemán and Rosa E. del Río

Molbank 2025, 2025(3), M2027; https://doi.org/10.3390/M2027 - 23 Jun 2025

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Abstract

(−)-Patagonic acid (1) is a clerodane diterpene isolated from several plants from the Alismataceae, Asteraceae, Euphorbiaceae, Fabaceae, Lamiaceae, Salicaceae, Sapindaceae, and Velloziaceae families, and its biological potential as an inhibitor of butyrylcholinesterase (BChE) and acetylcholinesterase (AChE) and as an anti-inflammatory compound [...] Read more.

(−)-Patagonic acid (1) is a clerodane diterpene isolated from several plants from the Alismataceae, Asteraceae, Euphorbiaceae, Fabaceae, Lamiaceae, Salicaceae, Sapindaceae, and Velloziaceae families, and its biological potential as an inhibitor of butyrylcholinesterase (BChE) and acetylcholinesterase (AChE) and as an anti-inflammatory compound has been described. Furthermore, the enantiomer (+)-1 is also described in Fabaceae and Verbenaceae. A lack of formal studies about the absolute configuration (AC) determination of 1 is emphasized. Thus, the present manuscript describes the AC determination of patagonic acid (1). The chemical correlation of (−)-1 from (−)-hardwickiic acid (2) was achieved by a simplistic oxidative process. The specific rotation value and electronic circular dichroism (ECD) analysis allowed for the AC determination of (−)-1 as (5R,8R,9S,10R)-(−)-patagonic acid. ECD revealed a positive exciton chirality (EC) phenomenon in both (−)-1 and (−)-2, which is directly associated with their configuration and conformational preferences, which were assessed by DFT calculations at the B3LYP/DGDZVP level of theory. Since the NMR data of (+)-1 are fully coincident with those from its enantiomer studied herein, the chirality of (5S,8S,9R,10S)-(+)-patagonic acid could also be determined. These experimental conclusions deeply complement the literature related to clerodane compounds biosynthesized in several families of plants of scientific interest. Full article

(This article belongs to the Section Natural Product Chemistry)

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5 pages, 335 KiB

Open AccessShort Note

2-(2-(Benzylamino)-2-Oxoethyl)-1-Methyl-1H-Pyrrole-3-Carboxylic Acid

by Monika Fryc, Beata Gryzło, Pravin Kumar and Agnieszka Zagórska

Molbank 2025, 2025(3), M2026; https://doi.org/10.3390/M2026 - 20 Jun 2025

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Abstract

Here, 2-(2-(Benzylamino)-2-oxoethyl)-1-methyl-1H-pyrrole-3-carboxylic acid was efficiently synthesised in good yield via an amide coupling reaction between 2-carboxymethyl-1-methyl-1H-pyrrole-3-carboxylic acid and benzylamine, employing TBTU as the coupling reagent and DIPEA as the base. The reaction was carried out in dichloromethane at room [...] Read more.

Here, 2-(2-(Benzylamino)-2-oxoethyl)-1-methyl-1H-pyrrole-3-carboxylic acid was efficiently synthesised in good yield via an amide coupling reaction between 2-carboxymethyl-1-methyl-1H-pyrrole-3-carboxylic acid and benzylamine, employing TBTU as the coupling reagent and DIPEA as the base. The reaction was carried out in dichloromethane at room temperature. The compound was characterised by melting point determination, ¹H and ¹³C NMR, IR spectroscopy, and mass spectrometry. The combined analytical data confirm the target molecule’s successful synthesis and structural integrity. Full article

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6 pages, 1320 KiB

Open AccessShort Note

N-(2-((2-(1H-indol-3-yl)ethyl)carbamoyl)phenyl)furan-2-carboxamide

by Diyana Dimitrova, Iliyan Ivanov, Stanimir Manolov and Dimitar Bojilov

Molbank 2025, 2025(3), M2025; https://doi.org/10.3390/M2025 - 20 Jun 2025

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Abstract

In the present study, we describe the synthesis of N-(2-((2-(1H-indol-3-yl)ethyl)carbamoyl)phenyl)furan-2-carboxamide via a two-step reaction sequence. Initially, isatoic anhydride was reacted with tryptamine to afford the corresponding intermediate, which was subsequently subjected to acylation using furan-2-carbonyl chloride. The final product was [...] Read more.

In the present study, we describe the synthesis of N-(2-((2-(1H-indol-3-yl)ethyl)carbamoyl)phenyl)furan-2-carboxamide via a two-step reaction sequence. Initially, isatoic anhydride was reacted with tryptamine to afford the corresponding intermediate, which was subsequently subjected to acylation using furan-2-carbonyl chloride. The final product was comprehensively characterized by melting point analysis, ¹H and ¹³C NMR, HSQC, IR, and MS spectrometry. The combined spectroscopic and analytical data unequivocally confirm the successful synthesis and structural integrity of the target compound. Full article

(This article belongs to the Section Structure Determination)

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Molbank, Volume 2025, Issue 3 (September 2025) – 11 articles

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