Article
Chemistry, Multidisciplinary
Oleg Grossmann, Rajat Maji, Miles H. Aukland, Sunggi Lee, Benjamin List
Summary: Strong and confined IDPi catalysts enable highly enantioselective substitutions of cyclic, aliphatic hemiaminal ethers with enol silanes, giving access to 2-substituted pyrrolidines, piperidines, and azepanes with high enantioselectivities. The method exhibits broad tolerance towards various enol silane nucleophiles. Mechanistic studies suggest the involvement of non-stabilized, cyclic N-(exo-acyl)iminium ions with the confined chiral counteranion as intermediates, while computational studies provide transition states that account for the observed enantioselectivity.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Organic
Nivesh Kumar, Claire Laye, Frederic Robert, Yannick Landais
Summary: Heteroarylsilyl cations derived from a quinoline skeleton exhibit high stability and interactions reinforced by substituents at the C4 position on the quinoline ring. DFT calculations and experimental data demonstrate the relatively high Lewis acidity of these silylium ions.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Roman G. Belli, Dimitrios A. Pantazis, Robert McDonald, Lisa Rosenberg
Summary: The study shows that a new Lewis superacid plays a key role in the electrophilic Si-H abstraction process of silanes and can act as a catalyst or initiator in catalytic reactions. By investigating the equilibrium between different adducts, the mechanism of its dominance in the catalytic hydrosilylation reaction is revealed.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Physical
Qingqing Luo, Zhou Tian, Jie Tang, Jie Wang, Yin Tian, Cheng Peng, Gu Zhan, Bo Han
Summary: The study focuses on the design of bifunctional 4-pyrrolidinopyridines as Lewis base catalysts, which exhibited excellent efficiency and stereoselectivity in asymmetric cycloaddition reactions. The research provides strong support for the construction of chiral spiropyrazolone derivatives.
Article
Chemistry, Inorganic & Nuclear
Aymeric Dajnak, Gul Altinbas Ozpinar, Romaric Lenk, Nathalie Saffon-Merceron, Antoine Baceiredo, Tsuyoshi Kato, Thomas Mueller, Eddy Maerten
Summary: A norbornene-based sulfide stabilized silylium ion 4 has been synthesized and its S-Si interaction has been studied. The silylium ion behaves as a Lewis acid and has emerged as an easy-to-handle catalyst for Diels-Alder cycloaddition and hydrodefluorination reactions.
DALTON TRANSACTIONS
(2022)
Article
Chemistry, Multidisciplinary
Nicolo Fontana, Noel Angel Espinosa-Jalapa, Michael Seidl, Jonathan O. Bauer
Summary: This study presents an efficient methodology for the synthesis of new Si-chiral four-membered CPSSi* heterocyclic cations, elucidates the stereochemical sequence and mechanisms involved, and demonstrates the ease of achieving chemoselectivity switch through slight modifications of the solvent. The intermolecularity of the reaction was supported by various experiments and quantum chemical calculations.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Multidisciplinary
Danila O. Zakharov, Konstantin Chernichenko, Kristina Sorochkina, Shengjun Yang, Ville-Veikko Telkki, Timo Repo, Vladimir V. Zhivonitko
Summary: In this study, we report the nuclear spin hyperpolarization of various alkenes achieved through alkyne hydrogenations with a metal-free hydroborane catalyst. The specific spin dynamics in catalytic intermediates leads to the hyperpolarization of one hydrogen in the alkene, allowing for advanced characterization of the catalytic process.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Multidisciplinary
Meng Duan, Christian David Diaz-Oviedo, Yang Zhou, Xiangyang Chen, Peiyuan Yu, Benjamin List, Kendall N. Houk, Yu Lan
Summary: Computations and experiments were conducted to develop new chiral phosphoric acids for epoxide thionations. It was found that bulky ortho-substituents on the CPA's 3,3'-aryl groups are crucial for restricting the epoxide position in key transition states for enantioselectivity-determining steps. Larger para-substituents significantly improve the enantioselectivity of the reaction.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Qingyu Zhang, Yung-Yin Chan, Muyin Zhang, Ying-Yeung Yeung, Zhihai Ke
Summary: This study presents a proof-of-concept for hypervalent chalcogenonium center dot center dot center dot pi bonding catalysis. A new catalytic strategy using 1,2-oxaselenolium salts as chalcogen bond donors and alkenes as chalcogen bond acceptors is described. The results demonstrate the feasibility of this concept and highlight the significant effect of counter anions on catalysis based on hypervalent chalcogenonium center dot center dot center dot pi bonding interactions.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Raphael Nougue, Shintaro Takahashi, Aymeric Dajnak, Eddy Maerten, Antoine Baceiredo, Nathalie Saffon-Merceron, Vicenc Branchadell, Tsuyoshi Kato
Summary: The behavior of several base-stabilized silyliumylidene ions with different ligands was found to be strongly influenced by the nature of the ligand. Among them, the silylene- and sulfide-supported complexes exhibited higher reactivity and were capable of sequentially activating multiple small molecules. Of particular interest, the silylene-supported silyliumylidene complex was able to activate two H2 molecules.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Physical
Kuldeep Singh, Idan Avigdori, Alexander Kaushansky, Natalia Fridman, Dor Toledano, Mark Gandelman
Summary: Nitrogen Lewis acids (NLAs) have emerged as a powerful tool in strong bond activation and catalysis. This article presents the synthesis and characterization of a new generation of nitrenium-based Lewis acids and demonstrates their efficiency in gram-scale hydrosilylation reactions. Experimental and theoretical studies provide insights into the mechanistic action of nitrenium Lewis acids in reduction-type reactions.
Article
Chemistry, Multidisciplinary
Kevin Blaesing, Rene Labbow, Axel Schulz, Alexander Villinger
Summary: The chemistry of silylated sulfuric acid was studied in detail in order to synthesize the formal autosilylation products, [T3SO4](+) and [TSO4](-). The successful synthesis of [TSO4](-) required the use of a base that forms a weakly coordinating cation upon silylation, while [T3SO4](+) salts could be isolated when a weakly coordinating anion was used as counterion. All silylated compounds were able to be crystallized and structurally characterized.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Haopeng Gao, Robert Mueller, Elisabeth Irran, Hendrik F. T. Klare, Martin Kaupp, Martin Oestreich
Summary: Potent main-group Lewis acids can activate element-hydrogen bonds. By designing a neutral precursor, the rivalry for hydride between silylium- and borenium-ion centers was investigated, revealing a novel Si-H-B linkage.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Multidisciplinary
Robin Weiss, Emmanuel Aubert, Patrick Pale, Victor Mamane
Summary: Chalcogen bonding between telluronium cations and Lewis bases was shown to have impressive catalytic properties in benchmark reactions. The interaction was confirmed through multi-nuclear NMR analysis and DFT calculations, highlighting the potential of telluronium cations as organocatalysts.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Organic
Kellsie Jurkowski, Eike B. Bauer
Summary: Ferrocenium cations are used as catalysts in organic transformations, and their decomposition rate constants depend on the nature of the counterion, with oxidative process being the main decomposition pathway. The cosolvent and changes in counterions can influence the catalytic activity.
SYNTHESIS-STUTTGART
(2021)
Review
Chemistry, Organic
Johannes E. Erchinger, Manuel van Gemmeren
Summary: This article discusses the combination of electrochemistry and Pd-catalyzed C-H activation/functionalization to achieve C-C, C-X, C-O, and C-P bond formation.
ASIAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Arup Mondal, Manuel van Gemmeren
Summary: Alkynes are important motifs in organic synthesis due to their presence in natural products and bioactive molecules. The method of inserting alkynes into (hetero)arenes relies heavily on the regioselectivity of the halogenation step, and can achieve selective alkynylation of thiophenes. The developed palladium-catalyzed C-H activation/alkynylation of thiophenes allows for regiodivergent reactions and late-stage modifications.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Editorial Material
Chemistry, Multidisciplinary
Sabine Bognar, Manuel van Gemmeren
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Multidisciplinary
Sabine Bognar, Manuel van Gemmeren
Summary: A synthetically simple general one-step protocol was developed for the selective synthesis of a broad range of unsymmetrical dithioacetals consisting of one aromatic and one aliphatic thiol moiety. The mixed S,S-acetals were obtained in high yields, demonstrating excellent selectivity.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Multidisciplinary
Philipp Wedi, Mirxan Farizyan, Klaus Bergander, Christian Mueck-Lichtenfeld, Manuel van Gemmeren
Summary: Recent discovery of palladium catalysts has enabled direct-group-free C-H activation of arenes without excess substrate, allowing for late-stage modification of complex organic molecules. The success lies in the use of two complementary ligands, N-acyl amino acid and N-heterocycle. Mechanistic studies have identified catalytically active species and a transition state model that explains the exceptional activity and selectivity of these catalysts, with potential for further method development.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Organic
Arianna Sinibaldi, Francesca Della Penna, Marco Ponzetti, Francesco Fini, Silvia Marchesan, Andrea Baschieri, Fabio Pesciaioli, Armando Carlone
Summary: Self-assembling minimalistic peptides with an organocatalytic moiety were designed and controlled by external intervention to accelerate activation. The accelerated catalysis was demonstrated in a Michael benchmark reaction.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Alexander Uttry, Sourjya Mal, Manuel van Gemmeren
Summary: The study describes the late-stage deuteration of free carboxylic acids and enables the functionalization of non-activated methylene beta-C(sp(3))-H bonds.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Physical
Valeria Nori, Fabio Pesciaioli, Arianna Sinibaldi, Giuliana Giorgianni, Armando Carlone
Summary: Boron-based catalysis has gained significant attention in organic synthesis. The use of halogenated triarylboranes as main group Lewis acid catalysts is an appealing strategy, and it has been increasingly employed in various transformations, often performing on par or even better than the gold standard catalysts.
Article
Chemistry, Multidisciplinary
Valeria Nori, Arianna Sinibaldi, Giuliana Giorgianni, Fabio Pesciaioli, Francesca Di Donato, Emanuele Cocco, Alessandra Biancolillo, Aitor Landa, Armando Carlone
Summary: The development of a rational approach for enantioselective enamine-catalysed addition of masked acetaldehyde to nitroalkenes has helped to replace the use of chloroform. The use of water as a reaction medium in this protocol improves the industrial relevance of accessing important pharmaceutical intermediates. The success of this research is attributed to the chemometrics-assisted 'Design of Experiments' (DoE) optimisation, which allows a rational exploration of the chemical space.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Review
Chemistry, Multidisciplinary
Antonio Del Vecchio, Arianna Sinibaldi, Valeria Nori, Giuliana Giorgianni, Graziano Di Carmine, Fabio Pesciaioli
Summary: Synergistic catalysis allows simultaneous activation of nucleophile and electrophile. Aminocatalysis has been established as a platform for selective activation of carbonyl compounds. The introduction of versatile and privileged chiral amines has greatly contributed to the rapid development of aminocatalysis.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Physical
Giuliana Giorgianni, Luca Bernardi, Francesco Fini, Fabio Pesciaioli, Francesco Secci, Armando Carlone
Summary: Enantioselective organocatalysis is a significant field in asymmetric catalysis with substantial impact on both academic and industrial settings. By using pregabalin as a case study, this Perspective demonstrates the various approaches of using organocatalysis in tackling reactions involving simple chiral molecules.
Article
Biochemistry & Molecular Biology
Davide Moi, Maria Chiara Cabua, Viktoria Velichko, Andrea Cocco, Annalisa Chiappone, Rita Mocci, Stefania Porcu, Monica Piras, Stefano Bianco, Fabio Pesciaioli, Francesco Secci
Summary: A straightforward continuous-flow method for the synthesis of cyclopropyl carbaldehydes and ketones has been developed using 2-hydroxycyclobutanones and aryl thiols. Under mild conditions, multigram quantities of cyclopropyl adducts can be easily obtained with the aid of acid-catalysis and reusable Amberlyst-35 as a catalyst. The physical-chemical properties of the packed bed and the continuous-flow system were characterized in detail through various analyses.
Article
Chemistry, Physical
Valeria Nori, Francesca Della Penna, Emanuele Cocco, Simone Mantegazza, Gabriele Razzetti, Giuseppe Quattrocchi, Fabio Pesciaioli, Armando Carlone
Summary: This article presents a milder and greener approach to improve the synthesis of Dibenzosuberone (DBS), a key intermediate for the synthesis of active pharmaceutical ingredients (APIs) used for treating diseases related to the central nervous system. The approach involves the use of immobilized catalysts to reduce waste production.
Article
Chemistry, Organic
Carlos Santiago, Hao Chen, Arup Mondal, Manuel van Gemmeren
Summary: In this study, dual ligand-based palladium catalysts were used for late-stage olefination of arenes, successfully functionalizing complex arene substrates. The method utilizes the arene as a limiting reactant and controls the regioselectivity of the transformation by the steric and electronic properties of the substrate, providing a new pathway for preparing regioisomers.
Article
Chemistry, Organic
Manuel van Gemmeren, Benjamin List
Summary: This article details the development of Select Crowd Reviewing from the initial idea through a pilot phase to its current status as the default method for evaluating manuscripts at Synlett and SynOpen. The workflow for manuscript evaluation using Select Crowd Reviewing is described, along with a discussion of the advantages it offers compared to traditional peer review.
