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13 pages, 1994 KiB

Open AccessArticle

Exploring the Photocatalytic Efficiency of Gold Nanoparticles Deposited on Ni-Al-Zr-Layered Double Hydroxides for Selective Glucose Oxidation

by Nihel Dib, Frédéric Sauvage, Lucie Quéhon, Khadidja Khaldi, Sumeya Bedrane, José Juan Calvino, Redouane Bachir, Ginesa Blanco and Gwladys Pourceau

Molecules 2025, 30(1), 13; https://doi.org/10.3390/molecules30010013 - 24 Dec 2024

Viewed by 751

Abstract

Confronting escalating challenges in energy security and environmental sustainability has intensified interest in renewable sources for fuels and chemicals. Among the most promising alternatives, sugars derived from biomass are emerging as a cornerstone in advancing an environmentally sustainable economy. Within this framework, the [...] Read more.

Confronting escalating challenges in energy security and environmental sustainability has intensified interest in renewable sources for fuels and chemicals. Among the most promising alternatives, sugars derived from biomass are emerging as a cornerstone in advancing an environmentally sustainable economy. Within this framework, the development of sunlight-driven carbohydrate oxidation is of significant interest, as it enables the production of a broad spectrum of high-value, bio-sourced chemicals through eco-friendly processes. Gold nanoparticles (Au NPs) immobilized on inorganic supports have demonstrated considerable potential in this area, although the methodology still requires further exploration. In this study, we explored the selective oxidation of glucose into the corresponding gluconic acid salt in presence of a novel Au/Ni-Al-Zr-layered double hydroxide (LDH) photocatalyst under standardized A.M. 1.5 G light illumination. To optimize the photocatalytic conditions, an experimental plan is herein proposed, highlighting the critical influences of both catalyst loading and pH. In optimal conditions, the Au catalyst demonstrated a high efficiency, achieving 87% glucose conversion and 100% selectivity towards gluconic acid in only 90 min. By means of long-pass filters to select the incident light energy to the photocatalytic reactor, we evidenced that the charge transfer processes were occurring from the Ni-Al-Zr LDH support to the gold nanoparticles, thus opening new directions towards further photocatalyst modifications. This work underlines the potential of Au/LDH materials for sunlight-driven photocatalysis and provides a pathway for the sustainable production of high-value chemicals from renewable biomass sources. Full article

(This article belongs to the Special Issue Metal-Catalyzed Organic Transformations: Expanding Horizons in Synthetic Methodology)

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14 pages, 2005 KiB

Open AccessFeature PaperArticle

Selectivity Control in Nitroaldol (Henry) Reaction by Changing the Basic Anion in a Chiral Copper(II) Complex Based on (S)-2-Aminomethylpyrrolidine and 3,5-Di-tert-butylsalicylaldehyde

by Olga V. Khromova, Lidiya V. Yashkina, Nadezhda V. Stoletova, Victor I. Maleev, Yuri N. Belokon and Vladimir A. Larionov

Molecules 2024, 29(21), 5207; https://doi.org/10.3390/molecules29215207 - 4 Nov 2024

Viewed by 1275

Abstract

This article is a continuation of our previous research on the catalytic capability of a chiral copper complex based on commercially available (S)-2-aminomethylpyrrolidine and 3,5-di-tert-butylsalicylaldehyde with various counter-anions in the asymmetric Henry reaction. Our findings indicate that depending on [...] Read more.

This article is a continuation of our previous research on the catalytic capability of a chiral copper complex based on commercially available (S)-2-aminomethylpyrrolidine and 3,5-di-tert-butylsalicylaldehyde with various counter-anions in the asymmetric Henry reaction. Our findings indicate that depending on the type of base used, chiral nitroalcohols with yields up to 98% and ee values up to 77%, as well as β-nitrostyrenes with yields up to 88%, can be produced. Additionally, it has been found that the outcome of the reaction and the catalytic properties of copper (II) complexes (S)-Cu1 and (S)-Cu2 are influenced by the structure of the aldehyde used. Full article

(This article belongs to the Special Issue Metal-Catalyzed Organic Transformations: Expanding Horizons in Synthetic Methodology)

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15 pages, 14229 KiB

Open AccessArticle

Trade-Off between Degradation Efficiency and Recyclability: Zeolite-Enhanced Ni_3−xCo_xS₄ Catalyst for Photocatalytic Degradation of Methylene Blue

by Rachel Anne E. Lagunay, Ritche Roi B. Adalim, Aruzhan Tleubekova, Diana Suleimenova, Marvin Jose F. Fernandez, Robert J. O’Reilly and Mannix P. Balanay

Molecules 2024, 29(17), 4167; https://doi.org/10.3390/molecules29174167 - 3 Sep 2024

Viewed by 1355

Abstract

We herein report successful syntheses of both nickel cobalt sulfide (NCS) and its composite with zeolite (NCS@Z) using a solvothermal method. Techniques such as EDX analysis, SEM, and molar ratio determination were used for product characterization. The incorporation of NCS significantly changed the [...] Read more.

We herein report successful syntheses of both nickel cobalt sulfide (NCS) and its composite with zeolite (NCS@Z) using a solvothermal method. Techniques such as EDX analysis, SEM, and molar ratio determination were used for product characterization. The incorporation of NCS significantly changed the surface roughness and active sites of the zeolite, improving the efficiency of methylene blue degradation and its reusability, especially under UV irradiation. In comparing the pseudo-first order rates, the highest degradation efficiency of methylene blue was achieved with NCS-2@Z, having a degradation extent of 91.07% under UV irradiation. This environmentally friendly approach offers a promising solution for the remediation of methylene blue contamination in various industries. Full article

(This article belongs to the Special Issue Metal-Catalyzed Organic Transformations: Expanding Horizons in Synthetic Methodology)

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12 pages, 1557 KiB

Open AccessArticle

Pallado-Catalyzed Cascade Synthesis of 2-Alkoxyquinolines from 1,3-Butadiynamides

by Illia Lenko, Alexander Mamontov, Carole Alayrac and Bernhard Witulski

Molecules 2024, 29(15), 3505; https://doi.org/10.3390/molecules29153505 - 26 Jul 2024

Viewed by 937

Abstract

A novel synthesis strategy to access 2-alkoxyquinoline derivatives via a palladium-driven cascade reaction is disclosed. Unlike classic methods based on the alkylation of 2-quinolones with alkyl halides, the present method benefits from the de novo assembly of the quinoline core starting from 1,3-butadiynamides. [...] Read more.

A novel synthesis strategy to access 2-alkoxyquinoline derivatives via a palladium-driven cascade reaction is disclosed. Unlike classic methods based on the alkylation of 2-quinolones with alkyl halides, the present method benefits from the de novo assembly of the quinoline core starting from 1,3-butadiynamides. Palladium-catalyzed reaction cascades with N-(2-iodophenyl)-N-tosyl-1,3-butadiynamides and primary alcohols as external nucleophiles proceed under mild reaction conditions and selectively deliver a variety of differently functionalized 4-alkenyl 2-alkoxyquinolines in a single batch transformation. Full article

(This article belongs to the Special Issue Metal-Catalyzed Organic Transformations: Expanding Horizons in Synthetic Methodology)

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16 pages, 3215 KiB

Open AccessArticle

P(V)-Promoted Rh-Catalyzed Highly Regioselective Hydroformylation of Styrenes under Mild Conditions

by Tong Ru, Yajiao Zhang, Qiuxiang Wei, Sheng Zuo, Zhenhua Jia and Fen-Er Chen

Molecules 2024, 29(9), 2039; https://doi.org/10.3390/molecules29092039 - 28 Apr 2024

Cited by 1 | Viewed by 1591

Abstract

Hydroformylation of olefins is widely used in the chemical industry due to its versatility and the ability to produce valuable aldehydes with 100% atom economy. Herein, a hybrid phosphate promoter was found to efficiently promote rhodium-catalyzed hydroformylation of styrenes under remarkably mild conditions [...] Read more.

Hydroformylation of olefins is widely used in the chemical industry due to its versatility and the ability to produce valuable aldehydes with 100% atom economy. Herein, a hybrid phosphate promoter was found to efficiently promote rhodium-catalyzed hydroformylation of styrenes under remarkably mild conditions with high regioselectivities. Preliminary mechanistic studies revealed that the weak coordination between the Rhodium and the P=O double bond of this pentavalent phosphate likely induced exceptional reactivity and high ratios of branched aldehydes to linear products. Full article

(This article belongs to the Special Issue Metal-Catalyzed Organic Transformations: Expanding Horizons in Synthetic Methodology)

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13 pages, 1869 KiB

Open AccessCommunication

Photoinduced Site-Selective Aryl C-H Borylation with Electron-Donor-Acceptor Complex Derived from B₂Pin₂ and Isoquinoline

by Manhong Li, Yi-Hui Deng, Qianqian Chang, Jinyuan Li, Chao Wang, Leifeng Wang and Tian-Yu Sun

Molecules 2024, 29(8), 1783; https://doi.org/10.3390/molecules29081783 - 14 Apr 2024

Cited by 1 | Viewed by 2291

Abstract

Due to boron’s metalloid properties, aromatic boron reagents are prevalent synthetic intermediates. The direct borylation of aryl C-H bonds for producing aromatic boron compounds offers an appealing, one-step solution. Despite significant advances in this field, achieving regioselective aryl C-H bond borylation using simple [...] Read more.

Due to boron’s metalloid properties, aromatic boron reagents are prevalent synthetic intermediates. The direct borylation of aryl C-H bonds for producing aromatic boron compounds offers an appealing, one-step solution. Despite significant advances in this field, achieving regioselective aryl C-H bond borylation using simple and readily available starting materials still remains a challenge. In this work, we attempted to enhance the reactivity of the electron-donor-acceptor (EDA) complex by selecting different bases to replace the organic base (NEt₃) used in our previous research. To our delight, when using NH₄HCO₃ as the base, we have achieved a mild visible-light-mediated aromatic C-H bond borylation reaction with exceptional regioselectivity (rr > 40:1 to single isomers). Compared with our previous borylation methodologies, this protocol provides a more efficient and broader scope for aryl C-H bond borylation through the use of N-Bromosuccinimide. The protocol’s good functional-group tolerance and excellent regioselectivity enable the functionalization of a variety of biologically relevant compounds and novel cascade transformations. Mechanistic experiments and theoretical calculations conducted in this study have indicated that, for certain arenes, the aryl C-H bond borylation might proceed through a new reaction mechanism, which involves the formation of a novel transient EDA complex. Full article

(This article belongs to the Special Issue Metal-Catalyzed Organic Transformations: Expanding Horizons in Synthetic Methodology)

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16 pages, 2692 KiB

Open AccessArticle

tert-Butyl Nitrite-Induced Radical Nitrile Oxidation Cycloaddition: Synthesis of Isoxazole/Isoxazoline-Fused Benzo 6/7/8-membered Oxacyclic Ketones

by Jian-Kang Cao, Tian-Zheng Cao, Qian-Wen Yue, Ying Ma, Chuan-Ming Yang, Hong-Xi Zhang, Ya-Chen Li, Qiao-Ke Dong, Yan-Ping Zhu and Yuan-Yuan Sun

Molecules 2024, 29(6), 1202; https://doi.org/10.3390/molecules29061202 - 7 Mar 2024

Cited by 1 | Viewed by 1814

Abstract

A practical metal-free and additive-free approach for the synthesis of 6/7/8-membered oxacyclic ketone-fused isoxazoles/isoxazolines tetracyclic or tricyclic structures is reported through C_sp³–H bond radical nitrile oxidation and the intramolecular cycloaddition of alkenyl/alkynyl-substituted aryl methyl ketones. This convenient approach enables the [...] Read more.

A practical metal-free and additive-free approach for the synthesis of 6/7/8-membered oxacyclic ketone-fused isoxazoles/isoxazolines tetracyclic or tricyclic structures is reported through C_sp³–H bond radical nitrile oxidation and the intramolecular cycloaddition of alkenyl/alkynyl-substituted aryl methyl ketones. This convenient approach enables the simultaneous formation of isoxazole/isoxazoline and 6/7/8-membered oxacyclic ketones to form polycyclic architectures by using tert-butyl nitrite (TBN) as a non-metallic radical initiator and N–O fragment donor. Full article

(This article belongs to the Special Issue Metal-Catalyzed Organic Transformations: Expanding Horizons in Synthetic Methodology)

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12 pages, 1737 KiB

Open AccessArticle

Enhanced Selectivity in 4-Quinolone Formation: A Dual-Base System for Palladium-Catalyzed Carbonylative Cyclization with Fe(CO)₅

by Meng Guo, Dou Wu, Hongyu Yang, Xiao Zhang, Dong-Xu Xue and Weiqiang Zhang

Molecules 2024, 29(4), 850; https://doi.org/10.3390/molecules29040850 - 14 Feb 2024

Cited by 1 | Viewed by 1123

Abstract

The use of gaseous CO in Pd-catalyzed carbonylative quinolone synthesis presents challenges related to safety and precise pressure control. In response, a streamlined non-gaseous synthesis of 4-quinolone compounds has been developed. This study introduces a tunable CO-releasing system utilizing Fe(CO)₅ activated by [...] Read more.

The use of gaseous CO in Pd-catalyzed carbonylative quinolone synthesis presents challenges related to safety and precise pressure control. In response, a streamlined non-gaseous synthesis of 4-quinolone compounds has been developed. This study introduces a tunable CO-releasing system utilizing Fe(CO)₅ activated by a dual-base system of piperazine and triethylamine. This alternative liquid CO resource facilitates the palladium-catalyzed carbonylative C-C coupling and subsequent intramolecular cyclization. By tuning the tandem kinetics of carbonylation and cyclization, this non-gaseous method achieves the successful synthesis of 22 distinct 4-quinolones with excellent yields. This is achieved through the three-component condensation of sub-stoichiometric amounts of Fe(CO)₅ with 2-iodoaniline and terminal alkynes. Operando mechanistic studies have revealed a novel CO transfer mechanism that facilitates homogeneous carbonylative cyclization, distinguishing this method from traditional techniques. In addition to addressing safety concerns, this approach also provides precise control over selectivity, with significant implications for pharmaceutical research and the efficient synthesis of pharmaceutical and bioactive compounds. Full article

(This article belongs to the Special Issue Metal-Catalyzed Organic Transformations: Expanding Horizons in Synthetic Methodology)

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Review

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44 pages, 115423 KiB

Open AccessReview

Research Progress in Epoxidation of Light Small-Molecule Olefins

by Guanghui Zhao, Tianfu Yang, Jincheng Liu, Xianming Xu, Yulong Wang, Yongjun Zhang, Meng Gao, Chao Xiong and Hongbing Ji

Molecules 2025, 30(6), 1340; https://doi.org/10.3390/molecules30061340 - 17 Mar 2025

Viewed by 637

Abstract

Light olefins, as important bulk raw materials in the petrochemical industry, play an irreplaceable role in the development of the manufacturing industry and the economy. The epoxides of light olefins are important intermediates for the synthesis of polymers, drugs, and fine chemicals, and [...] Read more.

Light olefins, as important bulk raw materials in the petrochemical industry, play an irreplaceable role in the development of the manufacturing industry and the economy. The epoxides of light olefins are important intermediates for the synthesis of polymers, drugs, and fine chemicals, and their green, efficient, and safe synthesis has attracted much attention. This review focuses on the research progress of light olefin epoxidation and elucidates traditional epoxidation methods, such as the chlorohydrin method. Although these processes have mature processes, they have drawbacks, including equipment corrosion, environmental pollution, poor safety, and high waste emissions. Special emphasis is placed on catalytic epoxidation systems using oxygen or organic peroxides as oxygen sources. For homogeneous catalytic systems, certain metal complexes exhibit high activity and selectivity yet are difficult to separate and recycle. Moreover, heterogeneous catalytic systems have become a research hotspot due to their advantages of easy separation and reusability, with supported metal catalysts being a prime example. Meanwhile, the effects of reaction temperature, pressure, solvent, etc., on epoxidation are explored. The specific reaction mechanisms are also studied and analyzed. Current research challenges, including enhancing catalyst stability and reducing costs, are summarized. In the future, developing highly efficient, green, and economically viable epoxidation technologies for large-scale industrial applications represents an important research direction in this field. Full article

(This article belongs to the Special Issue Metal-Catalyzed Organic Transformations: Expanding Horizons in Synthetic Methodology)

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