Article
Chemistry, Multidisciplinary
Takuji Fujii, Simone Gallarati, Clemence Corminboeuf, Qian Wang, Jieping Zhu
Summary: In this study, an efficient synthesis of diversely functionalized benzocyclobutenes (BCBs) was reported. The synthesis was achieved through a Pd(II)-catalyzed formal [2+2] annulation between arylboronic acids and alkenes in the presence of N-fluorobenzenesulfonimide (NFSI). The reaction mechanism was also proposed.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Multidisciplinary
Jiaxin Liu, Tonggang Hao, Ling Qian, Min Shi, Yin Wei
Summary: Here, we report a method for the synthesis of a wide range of benzocyclobutanol and benzocyclobutylamine derivatives through visible-light irradiation. The reaction involves the activation of remote C(sp(3))-H bonds of olefinic compounds and proceeds via a triplet biradical atom transfer mechanism. The reaction exhibits broad substrate scope and good functional group tolerance under mild reaction conditions.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Philip A. Provencher, John F. Hoskin, Jonathan J. Wong, Xiangyang Chen, Jin-Quan Yu, K. N. Houk, Erik J. Sorensen
Summary: The study presents a Pd(II)-catalyzed synthetic approach for methylene-selective C(sp(3))-H arylation of ketones, utilizing glycine as a directing group and a 2-pyridone ligand for methylene selectivity. The reaction exhibits high selectivity for intramolecular methylene C(sp(3))-H arylation, allowing for sequential C(sp(3))-H functionalization.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Physical
R. Tyler Mertens, Charles E. Greif, James T. Coogle, Gilles Berger, Sean Parkin, Mark D. Watson, Samuel G. Awuah
Summary: This study reports the development of a gold-catalyzed cross coupling reaction without oxidants, which can form biaryls without homocoupling of aryl halides. The study unveils the critical role of unsymmetrical tricoordinate Au(I) catalysts in this transformation.
JOURNAL OF CATALYSIS
(2022)
Article
Chemistry, Multidisciplinary
Paul L. Kress, Shengjie Zhang, Yicheng Wang, Volkan Cinar, Cynthia M. Friend, E. Charles H. Sykes, Matthew M. Montemore
Summary: Single-atom catalysts have limitations in facilitating reactions that require multiple adjacent sites. This study introduces trimetallic dual-atom alloys as a new class of catalysts with desirable reactivity. Experimental evidence shows that Pt-Cr sites in Ag(111) can catalyze the conversion of ethanol, while PtAg and CrAg are unreactive. The discovery of thermodynamically favorable dual-atom alloy sites opens up new possibilities for creating materials with enhanced chemical reactivity beyond the single-atom paradigm.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Organic
Zichen Wang, Huaquan Fang, Guixia Liu, Zheng Huang
Summary: In this study, a pincer Ru-catalyzed dual intramolecular dehydrogenative silylation of primary C(sp(3))-H bonds was reported. The reaction demonstrated high efficiency, scalability, and good functional group tolerance, allowing for facile and atom-economical access to structurally diverse silicon-centered spirocycles, including unprecedented oxa-spirosilabiindanes and aza-spirosilabiindanes.
Article
Chemistry, Multidisciplinary
Kai Liu, Tingrui Li, Duan-Yang Liu, Weipeng Li, Jian Han, Chengjian Zhu, Jin Xie
Summary: This study reports an unprecedented C-H bond functionalization of cyclopropenes enabled by dinuclear gold catalysis, resulting in highly selective C-H allylation, alkynylation, and halogenation reactions with organic halides. The reaction does not require strong external oxidants and affords access to functionalized cyclopropenes in moderate to good yields. The reductive elimination process for construct C-C or C-X bonds can be controlled by using different dinuclear gold catalysts.
SCIENCE CHINA-CHEMISTRY
(2021)
Article
Chemistry, Applied
Simone Battaglioli, Giulio Bertuzzi, Riccardo Pedrazzani, Jessica Benetti, Giovanni Valenti, Marco Montalti, Magda Monari, Marco Bandini
Summary: This study demonstrates the dehydrogenative functionalization of styryl carbon-carbon double bonds with triflamide via dual visible-light photoredox/cobaloxime catalysis. A variety of allylic triflamides were synthesized in moderate to good yields under stoichiometric acceptorless conditions (up to 88%). Our dedicated labelling and spectroscopic experiments provided insights into the concatenated photo- and chemo-catalytic cycles.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Organic
Dae-Kwon Kim, Minjung Keum, Heekyung Yun, Insu Kim, Jung Min Joo, Chulbom Lee
Summary: Here, we describe a rhodium-catalyzed oxygenative carbofunctionalization of terminal alkynes that leads to the regioselective quadruple formation of C-C, C-H, C-O, and C-heteroatom bonds. Mechanistic studies reveal that a disubstituted rhodium vinylidene complex is formed upon C-C bond formation, followed by intermolecular transfer oxygenation and reaction with heteroatom nucleophiles to generate cyclic carboxylic acid derivatives.
Article
Chemistry, Organic
Santosh Kumar Keshri, Suchithra Madhavan, Manmohan Kapur
Summary: Transition-metal catalysis has revolutionized organic synthesis by enabling efficient C-C and C-heteroatom bond formation. To functionalize nonbiased C-H bonds, various strategies have been developed, including the use of directing groups and substrate modification.
Article
Chemistry, Multidisciplinary
Duan-Yang Liu, Jie Han, Kai Liu, Yaohang Cheng, Hairen Tan, Xiaoliang Yang, Weipeng Li, Jin Xie
Summary: This study presents a gold-catalyzed para-C-H arylation reaction at room temperature, successfully applied to monofluoroarenes. The method shows high para-selectivity and a broad substrate scope, providing a concise and efficient strategy for constructing structurally diverse para-arylated monofluoroarenes.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Organic
Uros Todorovic, Immo Klose, Nuno Maulide
Summary: Thiocyanates, a versatile building block in organic synthesis, can be easily accessed through an interrupted Pummerer reaction of sulfoxides. This dealkylative functionalization can proceed under mild conditions by electrophilic activation of the sulfoxide partner, and the resulting thiocyanate can be used as a handle for diversification in a straightforward one-pot procedure.
Article
Chemistry, Organic
Hee Chan Noh, Cheol-Eui Kim, Kyungsup Lee, Dongwook Kim, Phil Ho Lee
Summary: A regioselective B(4)-alkenylation method has been developed using o-carboranyl sulfoxonium ylides and alkynes through B(4)-H activation catalyzed by Iridium(I). Sequential B(4)- and B(6)-alkenylation reactions resulted in the synthesis of B(3,5)-dialkenylated o-carboranyl sulfoxonium ylides in one pot. This method allows the introduction of two alkenyl groups at positions 3 and 5 of the carborane, with the sulfoxonium ylide serving as a directing group that can be further functionalized to B-alkenylated o-carboranyl trichloromethyl ketones.
Article
Chemistry, Organic
Mahadev Sharanappa Sherikar, Ravi Devarajappa, Kandikere Ramaiah Prabhu
Summary: The annulation of primary and secondary benzamide and cinnamamide derivatives using allyl alcohol as a coupling partner catalyzed by Rh(III) involves a dual role of Rh(III) as an oxidant and a catalyst for C-H activation. Mechanistic studies reveal the involvement of AgSbF6 in halide scavenging and cyclization reactions to form desired lactams, providing a useful method for synthesizing biologically active compounds.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Bichao Song, Xueying Guo, Li Yang, Haiyue Yu, Xinlei Zong, Xiujuan Liu, Hao Wang, Zhongliang Xu, Zhenyang Lin, Weibo Yang
Summary: Inspired by the C-H oxidation mechanism of cytochromes P450, a practical Rh-III-catalyzed acylmethylation macrocyclization via C-H/O-2 dual activation has been developed. The macrocyclization process is facilitated by a synergic coordination from pyridine and ester group. This unique reaction mode differs from established olefination and alkylation paths, and its mechanism has been revealed through density functional theory (DFT) calculations and control experiments. The newly achieved acylmethylation macrocyclic products and their derivatives exhibit potent anti-H1N1 bioactivity, which may lead to the discovery of novel anti-H1N1 macrocyclic leading compounds.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Applied
Vanessa Vethacke, Vanessa Claus, Martin C. Dietl, Daniel Ehjeij, Arne Meister, Jonas F. Huber, Leon K. Paschai Darian, Matthias Rudolph, Frank Rominger, A. Stephen K. Hashmi
Summary: A variety of unsymmetric diaryl gold N-acyclic carbene (NAC) complexes were successfully synthesized by three different methods, allowing access to new complexes and overcoming previous limitations in the isonitrile route. These new complexes also proved to be successful as pre-catalysts in gold-catalyzed phenol synthesis.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Multidisciplinary
Viktoriia Zubar, Andreas T. Haedler, Markus Schuette, A. Stephen K. Hashmi, Thomas Schaub
Summary: This report discusses the promising method of utilizing plastic waste through chemical recycling, specifically hydrogenative depolymerization using a Mn pincer complex catalyst. The key to success lies in the combination of the catalyst with elevated temperatures and appropriate solvents to ensure sufficient solubility of the polymers. The process successfully depolymerizes a wide range of polyurethane samples, releasing polyetherols and diaminotoluene in high yields.
Article
Chemistry, Applied
Nikolai A. Sitte, Francesca Ghiringhelli, Grigory A. Shevchenko, Frank Rominger, A. Stephen K. Hashmi, Thomas Schaub
Summary: A copper(I)/phosphine system that catalyzes the alkynylation of formaldehyde with acetylene or terminal alkynes is reported. The catalyst consisting of <1 mol% copper(I) phenylacetylide and a trialkyl bisphosphine ligand shows high selectivity towards the formation of propargyl alcohol. The biphasic water/toluene reaction mixture allows for the separation of targeted products and catalyst recycling.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Applied
Yufeng Wu, Chao Hu, Tao Wang, Lukas Eberle, A. Stephen K. Hashmi
Summary: The gold-catalyzed regioselective formation of 3-hydroxyquinoline is achieved by combining anthranils and alkynyl sulfones. The selective scission of the epoxide intermediate results from the thermodynamic stability difference of the resulting cation, as calculated by quantum chemical calculations. The subsequent semi-pinacol rearrangement leads to the 1,2-shift of an aryl or alkyl group originating from the sulfone. A gram-scale synthesis of 3-hydroxyquinoline further confirms the viability of this protocol for preparing this important scaffold.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Multidisciplinary
Robin Heckershoff, Tobias Schnitzer, Tim Diederich, Lukas Eberle, Petra Kramer, Frank Rominger, Matthias Rudolph, A. Stephen K. Hashmi
Summary: In this study, a straightforward synthetic method was developed to access new N-heterocyclic fluorophores with high yields, which are highly desired for organic electronic devices. The reaction protocol demonstrated great versatility in producing fluorophores with different substituents, functional groups, and substitution patterns. The photophysical properties of the synthesized fluorophores were also investigated, including their strong blue emission and the tunability of their properties through changes in solvent polarity or interactions with Lewis acids.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Inorganic & Nuclear
Martin C. Dietl, Vanessa Vethacke, Ali Keshavarzi, Florian F. Mulks, Frank Rominger, Matthias Rudolph, Ibraheem A. I. Mkhalid, A. Stephen K. Hashmi
Summary: A convenient one-pot method for the synthesis of bridged heterobimetallic gold(I) palladium(II) bis(acyclic diaminocarbene) complexes is introduced. The method takes advantage of the graduated nucleophilicities of aliphatic and aromatic amines connected via an aromatic unit, allowing for a straightforward access to bridged complexes from readily available isonitrile metal precursors.
Article
Chemistry, Inorganic & Nuclear
Niels Lichtenberger, Maximilian Menche, Katharina S. L. Rueck, Rocco Paciello, Ansgar Schaefer, Peter Comba, A. Stephen K. Hashmi, Thomas Schaub
Summary: The (hydroxy)carbonylation of tertiary aliphatic alcohols and their corresponding olefins using a Ni-based catalyst system has been investigated. This study provides detailed mechanistic insights and expands the understanding of Ni-catalyzed carbonylation reactions.
Article
Chemistry, Multidisciplinary
Cheng Zhang, Qian Chen, Lei Wang, Qiaoying Sun, Yangyang Yang, Matthias Rudolph, Frank Rominger, A. Stephen K. Hashmi
Summary: Here, we present a general and modular strategy for the rapid assembly of benzo[c]phenanthridine (BCP) derivatives using homogeneous gold catalysis. This strategy involves a selectively intramolecular cascade reaction followed by an intermolecular cyclization to form successive C-N and C-C bonds. By utilizing readily available nitriles as the nitrogen source, the products are obtained in good yield with excellent functional group compatibility.
SCIENCE CHINA-CHEMISTRY
(2022)
Article
Multidisciplinary Sciences
Hongming Jin, Wen-Yan Tong, Jing Zhang, Matthias Rudolph, Frank Rominger, Xu Shen, Shuanglin Qu, A. Stephen K. Hashmi
Summary: In this study, the divergent reactivity of Pt(II) and Au(III) catalysts in intermolecular annulations was investigated. It was found that the Au(III) catalysts are more likely to produce smaller ring structures. The results of this study are important for understanding the selective reactions of metal carbene intermediates.
NATURE COMMUNICATIONS
(2022)
Article
Chemistry, Physical
Maximilian Menche, Philippe Klein, Marko Hermsen, Robert Konrath, Tamal Ghosh, Jedrzej Wysocki, Martin Ernst, A. Stephen K. Hashmi, Ansgar Schaefer, Peter Comba, Thomas Schaub
Summary: The influence of the ligand backbone on the enantioselectivity in the ruthenium-catalyzed direct asymmetric reductive amination was studied. It was found that using ligands with a larger bite angle could significantly increase the enantioselectivity. However, despite various attempts, increasing the enantioselectivity was not possible with larger ligand backbones.
Article
Chemistry, Multidisciplinary
Robin Heckershoff, Garrett May, Janika Daeumer, Lukas Eberle, Petra Kraemer, Frank Rominger, Matthias Rudolph, Florian F. Mulks, A. Stephen K. Hashmi
Summary: This study discovered an entropy-induced selectivity switch in the gold-catalyzed intramolecular hydroarylation of 2-ethynyl N-aryl indoles, leading to the synthesis of indolo[1,2-a]quinolines. Experimental and computational investigations provided insight into the mechanism of this uncommon selectivity phenomenon. The methodology demonstrated high functional group tolerance and the potential for diverse applications as functional materials.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Organic
Alban Falconnet, Jan-Dirk Arndt, A. Stephen K. Hashmi, Thomas Schaub
Summary: The Friedel-Crafts sulfonylation for the synthesis of diaryl sulfones derivatives was achieved using triflic acid as the catalyst. The method showed good to excellent yield and high selectivity, and the catalyst and excess arene could be easily recovered and re-used.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Review
Chemistry, Applied
Qian Wang, Bifu Liu, Kejun Feng, A. Stephen K. Hashmi
Summary: Carboranes are a class of carbon-boron molecular clusters with remarkable characteristics, which can serve as useful building blocks in various fields. Organic modifications of carboranes can be achieved, and transition metal-catalyzed decarboxylation cross coupling reactions offer an opportunity for the B-H activation of carboranes.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Organic
Robin Heckershoff, Lukas Eberle, Nick Richert, Christian Delavier, Michael Bruckschlegel, Moritz R. Schaefer, Petra Kraemer, Frank Rominger, Matthias Rudolph, A. Stephen K. Hashmi
Summary: The Pictet-Spengler reaction was used to synthesize benzobispyrrolo[3,2-c]quinolines as new scaffolds for organic electronics. These compounds are nitrogen-enriched analogues of pi-extended indolocarbazoles obtained by replacing CH moieties with nitrogen atoms. Through the synthesis and characterization of 17 new compounds, and the use of X-ray crystallography, photophysical measurements, and computational methods, the study investigated the effects of different substituents on photophysical and electronical properties. It was found that introducing two nitrogen atoms to the molecule core significantly decreased the HOMO and LUMO energies and increased the optical and HOMO-LUMO gaps.
ORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Chemistry, Multidisciplinary
Hongwei Shi, Jun Li, Tao Wang, Matthias Rudolph, A. Stephen K. Hashmi
Summary: A catalyst- and additive-free sunlight-induced strategy for the autoxidation of a wide range of aldehydes to carboxylic acids is described. This method utilizes air as the source of oxygen and sunlight as the light source, offering green, highly atom-efficient, and low-cost synthesis. The reaction can be easily scaled up and can proceed smoothly even at lower temperature and in natural light.
