Review
Chemistry, Multidisciplinary
Purushothaman Rajeshwaran, Jonathan Trouve, Khalil Youssef, Rafael Gramage-Doria
Summary: The Wacker reaction is a significant industrial transformation that oxidizes olefins to ketones. However, it typically requires expensive palladium catalysts, which has led to the development of Wacker-type processes that avoid their use, allowing for more sustainable procedures.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Organic
Zaneta Papadopulu, Martin Oestreich
Summary: A method for the nonenzymatic kinetic resolution of sterically congested alcohols with a quaternary carbon atom in the beta-position is reported, using the catalyst system CuCl/NaOtBu/(R,R)-Ph-BPE together with a 3,5-xylyl-substituted tertiary hydrosilane to achieve enantioselective silylation of the hydroxy group. Several alcohols are obtained with good to excellent selectivity factors, and there are currently no other known straightforward methods to access these motifs.
Article
Chemistry, Multidisciplinary
Bingxiao Zheng, Jinliang Song, Haihong Wu, Shitao Han, Jianxin Zhai, Kaili Zhang, Wei Wu, Caiyun Xu, Mingyuan He, Buxing Han
Summary: This work describes the efficient Pd-catalyzed direct coupling of aryl ethers and morpholines to produce 4-cyclohexylmorpholines, revealing a mechanism involving the cleavage of C(Ar)-O bonds and subsequent reductive amination. The method offers a new approach for synthesizing useful fine chemicals with good yields.
Article
Chemistry, Organic
Rakesh R. Behera, Surajit Panda, Rahul Ghosh, A. Ashis Kumar, Bidraha Bagh
Summary: Efficient catalytic hydrosilylation of nitroarenes to form aromatic amines under solvent-free conditions using a well-defined manganese(II)-NNO pincer complex with low catalyst loading is reported. The reaction offers a sustainable alternative to classical hydrogenation and has potential utility in the preparation of commercial drug molecules.
Article
Chemistry, Multidisciplinary
Akash Kaithal, Himadri Sekhar Sasmal, Subhabrata Dutta, Felix Schafer, Lisa Schlichter, Frank Glorius
Summary: This study reports a catalytic approach to synthesizing cis-selective saturated carbo-and heterocyclic germanium compounds with a 3D framework through the hydrogenation of readily accessible aromatic germanes with a 2D framework. Nishimura's catalyst exhibited the best hydrogenation reactivity, achieving an isolated yield of up to 96%. The synthesized products showed versatile applications in coupling reactions and demonstrated orthogonal reactivity with boranes or silanes, acquiring a three-dimensional structure with high stability.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Review
Chemistry, Multidisciplinary
Juan C. C. Scaiano
Summary: The increasing popularity of applied photochemistry has led to a shift in practitioners, from traditional specialists to users from other fields who recognize the value of light as a reagent. This tutorial introduces Kasha's rule early on, focusing on the lowest singlet and triplet excited states to provide a quick entry for newcomers in the field. The goal is to give them a taste of the diverse resources available in the fascinating field of organic photochemistry and encourage further exploration.
CHEMICAL SOCIETY REVIEWS
(2023)
Article
Chemistry, Physical
Jose A. Forni, Vir H. Gandhi, Anastasios Polyzos
Summary: In this study, we report the photocatalytic carbonylative hydroacylation of styrenes with unactivated alkyl halides. By combining the visible-light catalytic cycle and flow chemistry, we achieved the synthesis of a diverse array of unsymmetric dialkyl ketones from energy-demanding alkyl bromides and iodides. The application of flow chemistry technology allows for the mild generation of functionalized C(sp(3))-rich ketone products with spatial resolution and broad functional group tolerance.
Article
Chemistry, Inorganic & Nuclear
Kyounghoon Lee, Christine M. Thomas
Summary: The study reports an alternative method for preparing multidentate phosphine ligands with alkyl substituents by replacing phosphine substituents in nickel-bound PNNP ligands. The stereoselectivity of reactions can be controlled by varying the reaction temperature, and the method allows for metallation and subsequent demetallation of the ligand. Competitive elimination of both alkyl and phenyl substituents and/or attenuated reactivity may occur in some reactions.
INORGANIC CHEMISTRY
(2021)
Review
Chemistry, Multidisciplinary
Antonella lenia Alfano, Heiko Lange, Margherita Brindisi
Summary: The formation of amide bonds is essential in organic and synthetic medicinal chemistry. In recent years, the application of flow chemistry in amide bond formation has shown significant advantages and potential for development. This review summarizes and compares various methods and discusses future needs and prospects for sustainable synthesis.
Article
Chemistry, Applied
Zhihui Sun, Ruixue Ji, Jintao Wu, Jianyou Zhao, Fang Fang, Fan Wang, Chao Jiang, Zhong-Quan Liu
Summary: We present a modified Clemmensen reduction in which aliphatic and aromatic aldehydes and ketones undergo deoxygenative hydrogenation and deuterization to form hydrocarbons and deuterocarbons when reacted with aqueous H(D)Cl in an undivided cell. This method has several notable features: 1) H+/D+ as the sources of H/D; 2) mild reaction conditions (room temperature, open flask, CH3CN and water as cosolvent); 3) easily scaled-up to 100 grams. A series of D-labeled drugs were successfully synthesized using this approach.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Chemistry, Applied
Kamil Czelej, Juan Carlos Colmenares, Katarzyna Jablczynska, Karol Cwieka, Lukasz Werner, Leon Gradon
Summary: This review summarizes the recent progress in plasmonic thermophotocatalysis, with a focus on sustainable hydrogen production. It discusses a wide range of topics including plasmon-related phenomena, plasmonic nanostructures, and the potential implementation of continuous-flow reactors for hydrogen production. Remaining challenges in the commercialization of this technology are highlighted.
Article
Chemistry, Organic
Jia-Yin Wang, Guigen Li, Wen-Juan Hao, Bo Jiang
Summary: A new asymmetric catalytic conjugate reduction method has been established for synthesizing enantioenriched cyclobuta[a]-naphthalen-4(2H)-ones using copper-bisphosphine complexes as catalysts, providing excellent regio- and enantioselectivities. This protocol is tolerant to a broad scope of substrates, exhibits high compatibility with various substituents, and offers excellent stereoselectivity.
Article
Chemistry, Physical
Antonio J. Fernandez-Ropero, Bartosz Zawadzki, Emil Kowalewski, Izabela S. Pieta, Miroslaw Krawczyk, Krzysztof Matus, Dmytro Lisovytskiy, Anna Srebowata
Summary: In this study, the catalytic performance of 1 wt.% Pd/gamma-Al2O3 for the hydrogenation of 2-methyl-3-butyn-2-ol in continuous-flow mode was evaluated under different pretreatment conditions. The high-temperature reduction led to the formation of Pd-Al species in addition to pure Pd, enhancing the catalytic activity for the semi-hydrogenation reaction.
Article
Biochemistry & Molecular Biology
Jack J. Bennett, Paul V. Murphy
Summary: In this study, a continuous flow procedure was developed for the synthesis of 1-Deoxynojirimycin (1-DNJ) from L-sorbose. The previous batch reactions required two steps and the use of an acid, while this study achieved the same sequence in one step using the H-Cube (R) MiniPlus continuous flow reactor. Subsequent reductive amination of 1-DNJ with butanal using the H-Cube (R) resulted in NB-DNJ.
CARBOHYDRATE RESEARCH
(2023)
Article
Chemistry, Multidisciplinary
Taylor O. Hope, Tamara Reyes-Robles, Keun Ah Ryu, Steven Mauries, Nicole Removski, Jacinthe Maisonneuve, Rob C. Oslund, Olugbeminiyi O. Fadeyi, Mathieu Frenette
Summary: We investigated the photocatalytic activation of phenols for tyrosine labelling using flavin-based photocatalysts, and found that the initial covalent binding between phenols and tyrosine is not radical addition, but radical-radical recombination. This proposed mechanism may also explain the mechanism of other reported tyrosine-tagging approaches. Competitive kinetics experiments showed the generation of phenoxyl radicals through multiple pathways involving the excited riboflavin-photocatalyst or singlet oxygen, increasing the likelihood of radical-radical recombination.
Article
Chemistry, Organic
Yang Li, Yali Liu, Di Hao, Chuntian Li, Yan Liu, Yanlong Gu, Luigi Vaccaro, Ping Liu
Summary: An efficient Cu(II)-catalyzed direct C-H trifluoromethylation of pyrrolo[1,2-a]quinoxalines with CF3SO2Na in the presence of K2S2O8 has been developed. The reaction provides a variety of C1-trifluoromethylated pyrrolo[1,2-a]quinoxaline products in moderate to good yields. This method demonstrates broad substrate scope, excellent regioselectivity, and gram-scale synthesis.
Article
Chemistry, Physical
Xuezhen Li, Jing He, Mingxi Du, Jie Zhang, Yanlong Gu, Luigi Vaccaro, Ping Liu
Summary: An efficient I-2/K2S2O8-promoted ring expansion of benzo[d]thiazole and 3-oxo-3-arylpropanenitrile was developed, yielding diverse 3-aryl-4H-benzo[b][1,4]thiazine-2-carbonitriles in moderate to excellent yields. The protocol is characterized by metal-free reaction conditions, stable starting materials, and good group tolerance. Mechanistic studies suggest the reaction may proceed via a free radical process.
MOLECULAR CATALYSIS
(2022)
Review
Chemistry, Physical
Federica Valentini, Assunta Marrocchi, Luigi Vaccaro
Summary: Liquid organic hydrogen carriers (LOHCs) are attractive materials that can generate hydrogen on site for the production of biofuel precursors, fuels, or fuel additives. This comprehensive review article provides an overview of the hydrogen transfer mechanisms for different LOHCs and discusses the importance of catalyst design and reaction condition selection.
ADVANCED ENERGY MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Nihad Salameh, Francesco Ferlin, Federica Valentini, Ioannis Anastasiou, Luigi Vaccaro
Summary: This article describes an effective synthetic protocol for the synthesis of oxindoles in flow based on a C(sp(3))-H activation process promoted by a supported N-heterocyclic carbene palladium heterogeneous catalytic system. The use of CPME as the reaction medium, along with the design of an efficient continuous flow reactor, has led to a waste-minimized intramolecular cyclization process.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2022)
Article
Biochemistry & Molecular Biology
Elena Petricci, Simone Zurzolo, Camilla Matassini, Samuele Maramai, Francesca Cardona, Andrea Goti, Maurizio Taddei
Summary: A general method for the synthesis of pyrrolizidine derivatives using intramolecular hydroaminomethylation protocol under microwave dielectric heating is reported. The use of ethanol as a solvent provides environmentally friendly conditions, and the ligand/catalyst system can be recycled without significant impact on yield.
Article
Biochemistry & Molecular Biology
Giusy Tassone, Marco Mazzorana, Stefano Mangani, Elena Petricci, Elena Cini, Giuseppe Giannini, Cecilia Pozzi, Samuele Maramai
Summary: This study presents the structural characterization of human heat shock protein 90 (hHsp90) in complex with the anticancer drug JMC31 using X-ray crystallography. The crystal structures of hHsp90 variants (K112R and K112A) in complex with JMC31 were also investigated to understand the role of residue 112 in ligand binding and its potential for the development of selective inhibitors.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2022)
Article
Chemistry, Organic
Tian Sang, Chuntian Li, Fan Jia, Jing He, Yan Liu, Luigi Vaccaro, Jichang Liu, Ping Liu
Summary: This study has developed a series of halogenated systems for pyrazolo[1,5-a]pyrimidines, achieving selective transformations by mono- and di-iodination using varying ratios of pyrazolo[1,5-a]pyrimidines and NIS. Additionally, the reaction with NBS or NCS produces unique dibrominated or dichlorinated products. The wide range of substrates, good functional group tolerance, and gram-scale synthesis demonstrate the potential application of this reaction.
POLYCYCLIC AROMATIC COMPOUNDS
(2023)
Review
Chemistry, Physical
Federica Valentini, Oriana Piermatti, Luigi Vaccaro
Summary: The direct functionalization of inactivated C-H bonds has gained attention as a method for step-economy, atom-efficient, and environmentally sustainable processes. The design and preparation of highly active metal nanoparticles as catalysts for C-H bond activation under mild reaction conditions is still being investigated. This review focuses on the functionalization of un-activated C(sp3)-H, C(sp2)-H, and C(sp)-H bonds using metal and metal oxide nanoparticles for C-O and C-X (X = Halogen, B, P, S, Se) bond formation, leading to more sustainable access to industrial production.
Article
Chemistry, Multidisciplinary
Federica Valentini, Giulia Brufani, Gabriele Rossini, Filippo Campana, Daniela Lanari, Luigi Vaccaro
Summary: We have developed a waste minimization protocol for the azidation reaction of a,fi-unsaturated carbonyl compounds using TMSN3. By selecting the appropriate catalyst (POLITAG-M-F) and reaction medium, we achieved enhanced catalytic efficiency and reduced environmental impact. The use of the CH3CN:H2O azeotrope as the reaction medium and for the workup procedure allowed for easy product isolation with high yield and low waste generation.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2023)
Review
Chemistry, Multidisciplinary
Dario Marchionni, Sumon Basak, Alireza Nazari Khodadadi, Assunta Marrocchi, Luigi Vaccaro
Summary: The past decade has witnessed a renewed interest in borazines and BN-doped polycyclic aromatic hydrocarbons due to their potential in various applications. This review critically examines the synthesis methods of (substituted) B3N3 motifs and focuses on the discussion of borazine-doped carbon structures developed for materials science applications.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Nihad Salameh, Federica Valentini, Olivier Baudoin, Luigi Vaccaro
Summary: We report a general and efficient enantioselective C-H arylation of aryl bromides using BozPhos as the bisphosphine ligand and SP-NHC-PdII as recoverable heterogeneous catalyst. By exploiting the release and catch mechanism of action, high enantioselectivities were achieved across different substrates containing methyl, cyclopropyl and aryl C-H bonds. The developed catalytic system provides a more sustainable solution for the synthesis of high added-value chiral products through recycling of the precious metal.
Article
Chemistry, Multidisciplinary
Giulia Brufani, Federica Valentini, Gabriele Rossini, Lucia Rosignoli, Yanlong Gu, Ping Liu, Luigi Vaccaro
Summary: Metal contamination is a significant problem in chemical synthesis, especially for products with biological activity. The use of appropriate operating conditions, such as a copper tube flow reactor (CTFR), can greatly reduce metal leaching and waste generation. A waste-minimized continuous flow process for synthesizing 1,4-disubstituted β-keto 1,2,3-triazoles was developed, which demonstrated low environmental impact through the measurement of various green metrics.
GREEN SYNTHESIS AND CATALYSIS
(2023)
Article
Chemistry, Multidisciplinary
Giulia Brufani, Federica Valentini, Gabriele Rossini, Luigi Carpisassi, Daniela Lanari, Luigi Vaccaro
Summary: We report a multi-step flow protocol for the synthesis of 1,4-disubstituted 1,2,3-triazoles starting from alpha,beta-unsaturated carbonyls. The best results were obtained using a sequential combination of two flow reactors: one packed with a tailor-made POLITAG-F organocatalytic system and a copper tube apparatus. The use of aqueous acetonitrile azeotrope led to excellent catalytic performances in both processes while minimizing waste.
Article
Chemistry, Multidisciplinary
Jose Luis Osorio-Tejada, Francesco Ferlin, Luigi Vaccaro, Volker Hessel
Summary: Carbon-to-carbon (C-C) cross-coupling reaction (CCR) protocols are a major breakthrough in synthetic chemistry, widely used in medicinal chemistry and other applied sciences. This study uses life cycle assessment (LCA) to evaluate the environmental impact of CCRs, separating intrinsic and extrinsic impacts. The findings suggest the need to recycle the catalyst, carefully choose the halobenzene, and recycle the ligand along with the catalyst.
