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9 pages, 1321 KiB

Open AccessArticle

Direct Synthesis of Allylic Sulfones via Hydrosulfonylation of 1,3-Dienes with Sulfinic Acids

by Ke Guo, Shuaichen Zhang, Jing Zhang, Yu Ren, Xiaoqiang Chang and Peng Sun

Molecules 2025, 30(8), 1785; https://doi.org/10.3390/molecules30081785 - 16 Apr 2025

Viewed by 638

Catalyst- and additive-free reactions for synthesizing valuable organic compounds have garnered significant attention in the context of sustainable development. As crucial structural motifs, allylic sulfones find extensive applications in pharmaceutical development and organic synthesis. Despite remarkable advances in allylic sulfone construction, catalyst-free and [...] Read more.

Catalyst- and additive-free reactions for synthesizing valuable organic compounds have garnered significant attention in the context of sustainable development. As crucial structural motifs, allylic sulfones find extensive applications in pharmaceutical development and organic synthesis. Despite remarkable advances in allylic sulfone construction, catalyst-free and additive-free methodologies remain an underexplored frontier. Herein, we present an environmentally benign and atom-economical approach for synthesizing allylic sulfones by reacting electron-rich aryl-1,3-dienes with sulfinic acids, achieving yields of 10–94%. This transformation proceeds under ambient air at room temperature, eliminating the need for catalysts or additives. The protocol demonstrates exceptional regio- and chemo-selectivity, streamlined operational simplicity, and excellent scalability potential. This methodology establishes a sustainable and cost-effective paradigm for allylic sulfone synthesis, aligning with green chemistry principles. Full article

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21 pages, 11946 KiB

Open AccessReview

The Versatility of the Roskamp Homologation in Synthesis

by Margherita Miele, Aljoša Smajić and Vittorio Pace

Molecules 2025, 30(6), 1192; https://doi.org/10.3390/molecules30061192 - 7 Mar 2025

Viewed by 1396

Abstract

Modern organic synthesis continues to benefit from the flexibility of α-diazo carbonyl intermediates. In the context of homologation processes, the Roskamp reaction—first introduced in 1989—has become a valuable tool due to its selectivity and mild condition reactions for accessing important synthons amenable to [...] Read more.

Modern organic synthesis continues to benefit from the flexibility of α-diazo carbonyl intermediates. In the context of homologation processes, the Roskamp reaction—first introduced in 1989—has become a valuable tool due to its selectivity and mild condition reactions for accessing important synthons amenable to further functionalization as β-keto esters. The fine-tuning of reaction parameters—including the nature of Lewis acids, solvents, and temperature—has enabled the development of catalyzed continuous-flow methodologies, as well as a series of asymmetric variants characterized by high transformation rates, excellent stereocontrol, and formidable chemoselectivity. This review aims to emphasize the attractive features of the Roskamp reaction and its applicability for addressing challenging homologation processes. Full article

(This article belongs to the Section Organic Chemistry)

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22 pages, 2638 KiB

Open AccessArticle

Computational and Experimental Studies on the α-Functionalization of Ketones Using Domino Reactions: A Strategy to Increase Chemoselectivity at the α-Carbon of Ketones

by Hui Sun, Li-Heng Yang, Meng-Yun Fu and Bin Cui

Molecules 2025, 30(5), 1114; https://doi.org/10.3390/molecules30051114 - 28 Feb 2025

Viewed by 657

Abstract

A facile strategy to increase the chemoselectivity of domino reactions was proposed and successfully applied in the α-functionalization of ketones. The strategy involved widening the activation energy of the main reaction and side reaction through intermolecular interactions, thereby increasing the chemoselectivity of the [...] Read more.

A facile strategy to increase the chemoselectivity of domino reactions was proposed and successfully applied in the α-functionalization of ketones. The strategy involved widening the activation energy of the main reaction and side reaction through intermolecular interactions, thereby increasing the chemoselectivity of the domino reaction. In the proposed α-functionalization reaction, TMSCF₃ acted as an excellent reagent which increased the nucleophilicity of DMF through the Van der Waals force and reduced the nucleophilicity of H₂O through a hydrogen bond. We found that TMSCF₃ can increase the activation energy difference between the main reaction and side reaction using DFT calculations, which greatly increased chemoselectivity and avoided the formation of by-products. TMSCF₃ was recycled by rectification, and the average recovery rate was 87.2%. DFT calculations, XRD experiments, and control experiments were performed to support this mechanism. We are confident that this strategy has the potential to deliver significant practical advancements while simultaneously fostering broader innovation in the field of domino synthesis. Full article

(This article belongs to the Special Issue Novel Methodologies of Organic Synthesis)

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8 pages, 1001 KiB

Open AccessArticle

Copper-Catalyzed Four-Component A³-Based Cascade Reaction: Facile Synthesis of 3-Oxetanone-Derived Spirocycles

by Rongkang Zhang, Liliang Huang, Aiguo Gu and Huangdi Feng

Chemistry 2025, 7(1), 19; https://doi.org/10.3390/chemistry7010019 - 4 Feb 2025

Viewed by 1563

Abstract

3-Oxetanone-derived spirooxazolidines represent a class of building blocks for accessing diverse saturated heterocycles, but their synthetic methods remain unexplored. Herein, we demonstrate a highly atom-economic approach for the synthesis of diverse 3-oxetanone-derived N-propargyl spirooxazolidines via a CuBr₂/TFA co-catalyzed four-component A [...] Read more.

3-Oxetanone-derived spirooxazolidines represent a class of building blocks for accessing diverse saturated heterocycles, but their synthetic methods remain unexplored. Herein, we demonstrate a highly atom-economic approach for the synthesis of diverse 3-oxetanone-derived N-propargyl spirooxazolidines via a CuBr₂/TFA co-catalyzed four-component A³-based cascade reaction of a 1,2-amino alcohol, a 3-oxetanone, a formaldehyde, and an alkyne. This strategy is characterized by a wide substrate range and excellent chemoselectivity. In addition, the synthesized spirocycles could also be easily converted into other valuable compounds, facilitating potentially useful synthetic applications. Full article

(This article belongs to the Special Issue Oxygen-Containing Heterocyclic Compounds: Recent Advances in Chemistry)

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20 pages, 5031 KiB

Open AccessArticle

5-Aminopyrazole Dimerization: Cu-Promoted Switchable Synthesis of Pyrazole-Fused Pyridazines and Pyrazines via Direct Coupling of C-H/N-H, C-H/C-H, and N-H/N-H Bonds

by Yi-Xin Chai, Jun-Jie Ren, Yi-Ming Li, Yi-Cheng Bai, Qing-Qing Zhang, Yi-Zhen Zhao, Xue Yang, Xiao-Han Zhang, Xin-Shuang Zhang, An-Xin Wu, Yan-Ping Zhu and Yuan-Yuan Sun

Molecules 2025, 30(2), 381; https://doi.org/10.3390/molecules30020381 - 17 Jan 2025

Viewed by 1878

Abstract

A Cu-promoted highly chemoselective dimerization of 5-aminopyrazoles to produce pyrazole-fused pyridazines and pyrazines is reported. The protocol generates switchable products via the direct coupling of C-H/N-H, C-H/C-H and N-H/N-H bonds, with the merits of broad substrate scope and high functional group compatibility. Gram-scale [...] Read more.

A Cu-promoted highly chemoselective dimerization of 5-aminopyrazoles to produce pyrazole-fused pyridazines and pyrazines is reported. The protocol generates switchable products via the direct coupling of C-H/N-H, C-H/C-H and N-H/N-H bonds, with the merits of broad substrate scope and high functional group compatibility. Gram-scale experiments demonstrated the potential applications of this reaction. Moreover, the preliminary fluorescence results uncovered that dipyrazole-fused pyridazines and pyrazines may have some potential applications in materials chemistry. Full article

(This article belongs to the Special Issue Cyclization Reactions in the Synthesis of Heterocyclic Compounds)

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14 pages, 3491 KiB

Open AccessFeature PaperArticle

Selective Synthesis of Isoquinoline-1-Carboxamides via Palladium-Catalyzed Aminocarbonylation in DMF and Biomass-Derived Solvents

by László Kollár, Nuray Uzunlu Ince, Alexandra Zugó, Ágnes Dörnyei and Attila Takács

Catalysts 2025, 15(1), 78; https://doi.org/10.3390/catal15010078 - 15 Jan 2025

Viewed by 1479

Abstract

In this study, the palladium-catalyzed aminocarbonylation of 1-iodoisoquinoline was accomplished in the presence of various amines. While the reactions with simple primary and secondary amines were carried out by using the well-known Pd(OAc)₂/PPh₃ catalyst, the application of amines with lower [...] Read more.

In this study, the palladium-catalyzed aminocarbonylation of 1-iodoisoquinoline was accomplished in the presence of various amines. While the reactions with simple primary and secondary amines were carried out by using the well-known Pd(OAc)₂/PPh₃ catalyst, the application of amines with lower basicity (e.g., aromatic amines) or more difficult structures (e.g., amino acid methyl esters, nortropine, diethyl (α-aminobenzyl)phosphonate) required the use of bidentate XantPhos ligand to achieve complete conversion in short reaction time (2–8 h). In this way, several valuable isoquinoline-1-carboxamides were synthesized in chemoselective carbonylation and isolated in good to high yields (55–89%). Furthermore, the aminocarbonylation of the model compound in the presence of several amines was also investigated in three biomass-derived solvents (GVL, ethyl levulinate, and 2-MeTHF). After comparing the outcome of the reactions in DMF and the above green solvents, similar reactivity was observed, justifying that they could be considered a feasible alternative reaction medium. Full article

(This article belongs to the Special Issue Catalysis in Heterocyclic and Organometallic Synthesis, 3rd Edition)

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16 pages, 3432 KiB

Open AccessArticle

Chemoselective Transfer Hydrogenation over MgO as the Catalyst: Acetylnaphthalenes, Diacylbenzenes, Acetophenone, Benzaldehyde, and Various Aliphatic Ketones as Hydrogen Acceptors

by Marek Gliński, Olga Dubinin, Klaudia Rostek and Patrycja Waniek

Reactions 2025, 6(1), 4; https://doi.org/10.3390/reactions6010004 - 4 Jan 2025

Cited by 2 | Viewed by 1118

Abstract

Liquid and vapor phase transfer hydrogenation with 2-alkanols as hydrogen donors in the presence of MgO as a catalyst was studied. A series of dicarbonyl compounds as well as the equimolar mixtures of various monocarbonyl compounds were used as hydrogen acceptors in order [...] Read more.

Liquid and vapor phase transfer hydrogenation with 2-alkanols as hydrogen donors in the presence of MgO as a catalyst was studied. A series of dicarbonyl compounds as well as the equimolar mixtures of various monocarbonyl compounds were used as hydrogen acceptors in order to determine the chemoselectivity (ChS) in the reduction of their carbonyl groups. Thus, 1,4-diacetylbenzene was reduced to 1-(4-acetylphenyl)-1-ethanol with 89% ChS and 1,3-diacetyl-4,6-dimethylbenzene with 100% ChS. Mesitylene diacyl derivatives were unreactive in the studied reaction. CTH of an equimolar mixture of benzaldehyde and acetophenone gave benzyl alcohol and 1-PhEtOH with yields of 91 and 3%, respectively (97% ChS). An equimolar mixture of acetophenone and 6-undecanone underwent CTH with yields of the corresponding alcohols of 89 and 2%, respectively, with 98% ChS towards 1-PhEtOH. Significant differences in reactivity in CTH were reported for an equimolar mixture of regioisomeric 1- and 2-acetylnaphthalenes. The yields of the corresponding alcohols were 20 and 68% with a ChS of 77% towards 2-NphCH(OH)Me. In the case of CTH of 3-oxo-2,2-dimethylbutanal and 2,4-bis(spirocyclohexyl)-1,3-cyclobutanedione with 2-propanol, only the solvolysis of the substrates was observed. The products were methyl isopropyl ketone and isopropyl formate for the former diketone and 1-(cyclohexylcarbonyl)-1-(carboisopropoxy)cyclohexane for the latter. Full article

(This article belongs to the Special Issue Feature Papers in Reactions in 2024)

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20 pages, 2879 KiB

Open AccessReview

Recent Progress on the Production of Liquid Fuel 2,5-Dimethylfuran via Chemoselective Hydrogenolysis Biomass-Derived 5-Hydroxymethylfurfural

by Jiadai He, Jiayi Peng, Renhui Ling and Jianjian Wang

Catalysts 2025, 15(1), 31; https://doi.org/10.3390/catal15010031 - 31 Dec 2024

Cited by 2 | Viewed by 1374

Abstract

5-Hydroxymethylfurfural (HMF) is regarded as an important representative of biomass-derived platform chemicals due to its multiple functional groups, including a hydroxyl group, aldehyde group, and furan ring within its molecular structure. Chemoselective hydrogenolysis of HMF to produce high-value-added liquid fuel 2,5-dimethylfuran (DMF) has [...] Read more.

5-Hydroxymethylfurfural (HMF) is regarded as an important representative of biomass-derived platform chemicals due to its multiple functional groups, including a hydroxyl group, aldehyde group, and furan ring within its molecular structure. Chemoselective hydrogenolysis of HMF to produce high-value-added liquid fuel 2,5-dimethylfuran (DMF) has emerged as a prominent area of research nowadays. The present review provides a comprehensive overview of the recent advancements in catalyst design for efficient DMF production from HMF, with a primary focus on elucidating the key factors influencing the hydrogenolysis reaction. This encompasses an extensive range of catalyst types and reaction conditions. Furthermore, the reaction mechanisms over the active sites of various catalysts are analyzed in depth. Drawing upon the comprehensive summary of existing research, this review discusses the future research prospects of the catalytic hydrogenolysis of HMF and provides valuable insights for the efficient conversion of biomass resources. Full article

(This article belongs to the Special Issue Heterogeneous Catalysis Towards a Sustainable Future)

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26 pages, 1943 KiB

Open AccessArticle

Rh(II)/Pd(0) Dual Catalysis: Carbenoid N-H Insertion/Allylation Cascade Reaction to Construct Highly Functionalized and Polysubstituted Pyrrolidines

by Maocheng Tang, Xianyan Jiao, Deping He, Ji-Xing Zhao, Ping Liu and Chun-Tian Li

Molecules 2024, 29(24), 5880; https://doi.org/10.3390/molecules29245880 - 13 Dec 2024

Viewed by 727

Abstract

In the category of drugs approved by the U.S. FDA, pyrrolidine is the most frequently used core of five-membered nonaromatic heterocycles containing nitrogen. Herein, a Rh(II)/Pd(0) dual-catalyzed carbenoid N-H insertion/allylation cascade reaction has been developed. This protocol provide an efficient approach for the [...] Read more.

In the category of drugs approved by the U.S. FDA, pyrrolidine is the most frequently used core of five-membered nonaromatic heterocycles containing nitrogen. Herein, a Rh(II)/Pd(0) dual-catalyzed carbenoid N-H insertion/allylation cascade reaction has been developed. This protocol provide an efficient approach for the construction of diverse highly functionalized and polysubstituted pyrrolidines in high yields (up to 91%) with excellent chemoselectivities and high diastereoselectivities (>20:1) under mild reaction conditions. Full article

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13 pages, 3781 KiB

Open AccessCommunication

Initial Examinations of the Diastereoselectivity and Chemoselectivity of Intramolecular Silyl Nitronate [3+2] Cycloadditions with Alkenyl/Alkynyl Nitroethers

by Katelyn Stevens, Shik Ki Li, Emily Kaufman, Annika Schull, Katie Hassebroek, Joseph Stevens, Matthew Grandbois, Arlen Viste and Jetty Duffy-Matzner

Molecules 2024, 29(24), 5816; https://doi.org/10.3390/molecules29245816 - 10 Dec 2024

Viewed by 1113

Abstract

This study examined the chemoselectivity and diastereoselectivity of silyl nitronate alkenyn-nitroethers in Intramolecular Silyl Nitronate Cycloadditions (ISNCs) to produce isoxazole derivatives with interesting medicinal properties. These reactions resulted in the formation of either dihydrofuro[3,4-c]isoxazolines/isoxazolidines and/or alkynyl moieties attached to 2,5-dihydrofuryl carbonyls. This study [...] Read more.

This study examined the chemoselectivity and diastereoselectivity of silyl nitronate alkenyn-nitroethers in Intramolecular Silyl Nitronate Cycloadditions (ISNCs) to produce isoxazole derivatives with interesting medicinal properties. These reactions resulted in the formation of either dihydrofuro[3,4-c]isoxazolines/isoxazolidines and/or alkynyl moieties attached to 2,5-dihydrofuryl carbonyls. This study also discerned the diastereoselectivities of the resulting cyclic adducts and compared them to previous findings. The reactions were also investigated with Spartan molecular modeling computations to aid in the understanding of any displayed chemo- and/or stereoselectivity. These [3+2]-cycloaddition reactions demonstrated excellent to complete chemospecificity. The cycloadditions also demonstrated remarkable diastereospecificity in that each diastereomer of the nitroethers resulted in the formation of only one of four possible diastereomeric outcomes. The stereochemistry of the major diastereomers did not agree with previously published findings. Full article

(This article belongs to the Special Issue Synthesis of Heterocyclic Compounds via Cycloadditions: Applications in Medicinal Chemistry)

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21 pages, 7077 KiB

Open AccessReview

Transition-Metal-Catalyzed C(sp³)–H Alkylation of Methyl Heteroarenes with Alcohols

by Bin Guo, Jing Zhang, Lin He, Xin-Yuan Zhou, Kai-Wen Xing, David J. Young and Hong-Xi Li

Catalysts 2024, 14(12), 881; https://doi.org/10.3390/catal14120881 - 3 Dec 2024

Cited by 1 | Viewed by 1588

Abstract

Transition-metal-catalyzed C(sp³)-H bond functionalization is a useful transformation for the construction of C–C bonds. A versatile and easy-to-perform protocol in this respect is the C-alkylation of methyl heteroarenes with alcohols using auto-transfer hydrogenative (ATH) reactions. Various transition metal catalysts based on [...] Read more.

Transition-metal-catalyzed C(sp³)-H bond functionalization is a useful transformation for the construction of C–C bonds. A versatile and easy-to-perform protocol in this respect is the C-alkylation of methyl heteroarenes with alcohols using auto-transfer hydrogenative (ATH) reactions. Various transition metal catalysts based on Ir, Pt, Ru, Ni, Co, Fe and Mn have been employed for the construction of chain-elongated alkyl-substituted heterocyclic compounds using this chemistry. Water is the only byproduct and the starting alcohols are less toxic, readily available, more easily handled and more atom-economical substrates than their halogen counterparts. This review details recent advances in this synthetic methodology, describing the scope, reaction mechanism, chemo-selectivity and applications. Full article

(This article belongs to the Special Issue Catalysis in Heterocyclic and Organometallic Synthesis, 3rd Edition)

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11 pages, 2870 KiB

Open AccessArticle

Palladium-Catalyzed Selective Carbonylation Reactions of Ortho-Phenylene Dihalides with Bifunctional N,O-Nucleophiles

by Fanni Bede, Attila Takács, László Kollár and Péter Pongrácz

Molecules 2024, 29(23), 5620; https://doi.org/10.3390/molecules29235620 - 27 Nov 2024

Viewed by 1303

Abstract

Palladium-catalyzed carbonylation reactions of ortho-phenylene dihalides were studied using aminoethanols as heterobifunctional N,O-nucleophiles. The activity of aryl-iodide and -bromide as well as the chemoselective transformation of amine and hydroxyl functionalities were studied systematically under carbonylation conditions. Aminocarbonylation can be [...] Read more.

Palladium-catalyzed carbonylation reactions of ortho-phenylene dihalides were studied using aminoethanols as heterobifunctional N,O-nucleophiles. The activity of aryl-iodide and -bromide as well as the chemoselective transformation of amine and hydroxyl functionalities were studied systematically under carbonylation conditions. Aminocarbonylation can be selectively realized under optimized conditions, enabling the formation of amide alcohols, and the challenging alkoxycarbonylation can also be proved feasible, enabling amide-ester production. Intramolecular double carbonylation reaction can be achieved using 1,2-diiodobenzene and amino alcohols featuring secondary amine groups, giving oxazocine derivatives. Useful reaction scope with various amino alcohols was performed with good isolated yields of the targeted compounds. Intramolecular C-O coupling of amide alcohols possessing bromo substituent in adjacent ortho position is also demonstrated as a potential next step in benzoxazepine heterocycle formation. Full article

(This article belongs to the Special Issue Advances in Transition-Metal-Catalyzed Synthesis)

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14 pages, 5710 KiB

Open AccessArticle

Hydrogenation Versus Hydrosilylation: The Substantial Impact of a Palladium Capsule on the Catalytic Outcome

by Maxime Steinmetz, Rachel Schurhammer, Christophe Gourlaouen and David Sémeril

Molecules 2024, 29(20), 4910; https://doi.org/10.3390/molecules29204910 - 17 Oct 2024

Viewed by 1011

Abstract

A palladium capsule, made of three cavitands, namely P,P-dichlorido{5,17-bis[5-(diphenylphosphanyl)-4(24),6(10),12(16),18(22)-tetramethylenedioxy-2,8,14,20-tetrapentylresorcin[4]arenyl-17-oxymthyl]-4(24),6(10),12(16),18(22)-tetramethylenedioxy-2,8,14,20-tetrapentylresorcin[4]arene}palladium(II) (1), was synthetized by coordination of the corresponding diphosphinated ligand and the palladium precursor [PdCl₂(PhCN)₂] in 27% yield. The obtained P,P-chelate complex [...] Read more.

A palladium capsule, made of three cavitands, namely P,P-dichlorido{5,17-bis[5-(diphenylphosphanyl)-4(24),6(10),12(16),18(22)-tetramethylenedioxy-2,8,14,20-tetrapentylresorcin[4]arenyl-17-oxymthyl]-4(24),6(10),12(16),18(22)-tetramethylenedioxy-2,8,14,20-tetrapentylresorcin[4]arene}palladium(II) (1), was synthetized by coordination of the corresponding diphosphinated ligand and the palladium precursor [PdCl₂(PhCN)₂] in 27% yield. The obtained P,P-chelate complex was fully characterized by elemental analysis, NMR and mass spectrometry. Molecular dynamics simulations carried out on the metallo-capsule showed the structure made by the three cavitands was slightly distorted over the 1 μs of the simulation. The evaluation of the palladium capsule 1 in the reaction between arylacetylenes and Et₃SiH in undried conditions unequivocally demonstrates a drastic change in chemoselectivity, with the formation of the partially hydrogenation product rather than the hydrosilylation products observed with complexes whose active center is more accessible, for instance [PdCl₂(PPh₃)₂]. Full article

(This article belongs to the Section Organometallic Chemistry)

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5 pages, 1385 KiB

Open AccessShort Note

Ac-[K-Aib-C(3,9-Acm; 6,12-DFLC₍_Acm₎KKESEK)]₄-NH₂

by Vasiliki Moulasioti, Evgenia Fotou, Vassilios Moussis and Vassilios Tsikaris

Molbank 2024, 2024(4), M1887; https://doi.org/10.3390/M1887 - 25 Sep 2024

Viewed by 749

Abstract

Chemoselective reactions have played a crucial role in the development of high-molecular-weight (>3000 Da) macromolecules with a branched architecture, particularly as peptides and epitope-based vaccines have emerged as promising tools for drug development. Based on this, in this study, we designed and synthesized [...] Read more.

Chemoselective reactions have played a crucial role in the development of high-molecular-weight (>3000 Da) macromolecules with a branched architecture, particularly as peptides and epitope-based vaccines have emerged as promising tools for drug development. Based on this, in this study, we designed and synthesized the peptide macromolecule CH₃CO-[K-Aib-C(3,9-CH₂NHCOCH₃; 6,12-DFLC(CH₂NHCOCH₃)KKESEK)]₄-NH₂ [Ac-K-Aib-C(3,9-Acm); 6,12-epitope)]₄-NH₂] using chemoselective thioether bond formation between the peptide carrier CPSOC (3,9 Acm) and the IAc-DFLC_(Acm)KKESEK-NH₂ peptide epitope. The conjugate was purified via RP-HPLC and characterized via HR-ESI-MS. The epitope D¹²⁸FLCKKESEK¹³⁷ derives from the lethal toxin, ammodytoxin A, from the V. ammodytes snake species, and it was synthesized using the SPPS Fmoc/tBu methodology and characterized via HR-ESI-MS and NMR techniques. Full article

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23 pages, 4787 KiB

Open AccessArticle

The Facile Production of p-Chloroaniline Facilitated by an Efficient and Chemoselective Metal-Free N/S Co-Doped Carbon Catalyst

by Juan-José Villora-Picó, Gema Gil-Muñoz, Antonio Sepúlveda-Escribano and M. Mercedes Pastor-Blas

Int. J. Mol. Sci. 2024, 25(17), 9603; https://doi.org/10.3390/ijms25179603 - 4 Sep 2024

Viewed by 2075

Abstract

The catalytic hydrogenation of the toxic and harmful p-chloronitrobenzene to produce the value-added p-chloroaniline is an essential reaction for the sustainable chemical industry. Nevertheless, ensuring satisfactory control of its chemoselectivity is a great challenge. In this work, a N/S co-doped metal-free [...] Read more.

The catalytic hydrogenation of the toxic and harmful p-chloronitrobenzene to produce the value-added p-chloroaniline is an essential reaction for the sustainable chemical industry. Nevertheless, ensuring satisfactory control of its chemoselectivity is a great challenge. In this work, a N/S co-doped metal-free carbon catalyst has been fabricated by using cysteine as a source of C, N, and S. The presence of calcium citrate (porogen agent) in the mixture subjected to pyrolysis provided the carbon with porosity, which permitted us to overcome the issues associated with the loss of heteroatoms during an otherwise necessary activation thermal treatment. Full characterization was carried out and the catalytic performance of the metal-free carbon material was tested in the hydrogenation reaction of p-chloronitrobenzene to selectively produce p-chloroaniline. Full selectivity was obtained but conversion was highly dependent on the introduction of S due to the synergetic effect of S and N heteroatoms. The N/S co-doped carbon (CYSCIT) exhibits a mesoporous architecture which favors mass transfer and a higher doping level, with more exposed N and S doping atoms which act as catalytic sites for the hydrogenation of p-chloronitrobenzene, resulting in enhanced catalytic performance when compared to the N-doped carbon obtained from melamine and calcium citrate (MELCIT) used as a reference. Full article

(This article belongs to the Special Issue Advanced Catalytic Materials (Second Edition))

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