Article
Chemistry, Organic
Dhananjay S. Nipate, Vikki N. Shinde, Krishnan Rangan, Anil Kumar
Summary: A condition-based switchable regioselective hydroalkylation of 2-arylindoles with maleimides has been developed. The reaction in the presence of a Ru(ii)-catalyst resulted in hydroalkylation at the ortho-position of the C2-aryl ring via C-H activation whereas the reaction in the absence of the catalyst in TFE resulted in C3-hydroalkylation. Various functional groups both on the indole ring and on the 2-phenyl ring were tolerated and a wide range of hydroalkylated products were obtained in moderate to high (37-88%) yields.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Changcheng Jing, Wenbin Mao, John F. Bower
Summary: Upon exposure to a cationic Ir(I)-complex modified with the chiral diphosphine DuanPhos, hydroalkylations of styrenes and alpha-olefins with diverse heteroaryl tert-butyl acetates occur with complete branched selectivity and very high enantioselectivity. The initial adducts undergo acid promoted decarboxylation in situ to provide alkylated heteroarenes possessing defined beta-stereocenters. The processes are postulated to proceed via a stereodefined chiral Ir-enolate, which arises upon heteroarene directed enolization of the heteroaryl acetate precursor. The method can be classified as an enantioselective decarboxylative C(sp(3))-C(sp(3)) cross-coupling.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Yan Li, Deguang Liu, Lei Wan, Jun-Yang Zhang, Xi Lu, Yao Fu
Summary: In this study, a ligand-controlled cobalt-catalyzed regiodivergent alkyne hydroalkylation method is reported, which can generate different isomers of an alkene from the same alkyne starting material. The method provides reliable and predictable protocols with high selectivity for the synthesis of specific alkenes.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Organic
Fei Yu, Chuang Li, Chuangye Wang, Hongwei Zhang, Zhong-Yan Cao
Summary: A new, simple, and easily accessible (1-selenocyanatoethyl)-benzene has been developed and used as a SeCN group transfer reagent for selenocyanation of aliphatic C(sp(3))-H bonds for the first time. The protocol features mild reaction conditions and a wide substrate scope, with control experiments suggesting a radical-group transfer mechanism may be involved.
Article
Chemistry, Organic
Ashfaq Ahmad, Himangsu Sekhar Dutta, Mohit Kumar, Raziullah, Manoj Kumar Gangwar, Dipankar Koley
Summary: A palladium catalyzed directing group assisted cross-coupling reaction has been developed for the synthesis of β-arylethylamine derivatives. The method is applicable to a wide range of substrates and can tolerate the presence of various external additives.
Article
Chemistry, Organic
Vikki N. Shinde, Bhawani Bhawani, Dhanajay S. Nipate, Sonam Sonam, Neha Meena, Krishnan Rangan, Dalip Kumar, Anil Kumar
Summary: A regioselective manganese-catalyzed ortho-hydroalkyla-tion of aryl-substituted N-heteroaromatic compounds with a range of maleimides is described. The developed C-H bond functionalization protocol allowed the introduction of the succinimide motif at the ortho- position of the aryl ring of N-heteroaromatic compounds, such as 2-arylimidazo[1,2-a]pyridines, 2-arylindazoles, 2-phenylpyridine, 2-phenyl-pyrimidine, 2-phenylimidazo[1,2-a]pyrimidine, 2-phenylimidazo[2,1-b]-thiazole, 2-phenylbenzo[d]imidazo[2,1-b]thiazole, 1-phenylindazole and 1-phenylpyrazole, to produce 3-(2-(N-heteroaryl)aryl)pyrrolidine-2,5-diones in good yields. The protocol exhibited broad substrate scope, good functional group tolerance and excellent regioselectivity under mild and additive-free reaction conditions.
SYNTHESIS-STUTTGART
(2023)
Article
Chemistry, Organic
Xiang Zhao, Xuelin Yue, Zeng Han, Yadong Feng, Ting Gao, Sanshu Li, Xiuling Cui
Summary: An efficient method for the synthesis of 6-alkenylindazolo[3,2-a]isoquinolines via rhodium(iii)-catalysed C-H bond activation/subsequent [4 + 2] cyclization has been developed. The obtained products exhibited excellent regioselectivity and fluorescence properties, making them suitable for DNA staining and labeling of zebrafish larvae yolk.
ORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Chemistry, Multidisciplinary
Zhi-Jiang Jiang, Si-Han Xu, Yuhang Su, Erxun Hu, Jiawei Han, Jian-Fei Bai, Bencan Tang, Jia Chen, Zhanghua Gao
Summary: A nickel-catalyzed hydrogen isotope exchange has been developed using acetone-d6 as the deuterium source. With the assistance of 2-pyridones, the reaction exhibits improved kinetic features of H/D exchange, leading to the efficient synthesis of regioselective labeled aryl and alkyl carboxamides.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Yu-Han Lu, Si-Yu Mu, Hong-Xia Li, Jun Jiang, Chao Wu, Min-Hang Zhou, Wen-Tao Ouyang, Wei-Min He
Summary: By utilizing formaldehyde as an atom-economical carbonyl synthon, a novel EtOH-catalyzed electrochemical multicomponent synthesis of imidazolidine-fused sulfamidates was developed. The reaction provided a wide range of products in good to excellent yields under organic oxidant-free, energy-saving, and mild conditions. Mechanistic studies revealed that the in situ generated ethoxide played a crucial role in producing aminomethylene radicals at a lower voltage.
Article
Chemistry, Organic
Tong-Xin Liu, Xue Zhu, Shilu Xia, Xin Wang, Pengling Zhang, Guisheng Zhang
Summary: This article introduces a novel catalytic method for the flexible and efficient preparation of diverse monoalkylated hydrofullerenes. The protocol features organic catalysis, broad substrate scope, excellent functional group tolerance, and products with high diversity and complexity levels.
Article
Chemistry, Organic
Peng-Cheng Cui, Zheng-Chun Yin, Guan-Wu Wang
Summary: The visible-light-promoted C4-selective phosphorylation of unprefunctionalized pyridine and quinoline derivatives has been achieved. This Minisci-type protocol offers highly regioselective access to C4-phosphorylation products with good functional group tolerance and moderate to good yields via cross dehydrogenation coupling under mild conditions. Mechanistic studies demonstrate that the C4-phosphorylation products are obtained through a radical pathway.
Article
Chemistry, Organic
Alexandria N. Leveille, Radell Echemendia, Anita E. Mattson, Antonio C. B. Burtoloso
Summary: The study reported the first example of organocatalytic enantioselective C-H insertion reactions of indoles and sulfoxonium ylides, achieving levels of enantiocontrol in the range of 20-93% ee and moderate yields (up to 50%) under phosphoric acid catalysis. It was found that no nitrogen protection on the indole is necessary for these reactions.
Article
Chemistry, Organic
Guanghua Kuang, Dandan Liu, Xuerong Chen, Guangyuan Liu, Yang Fu, Yiyuan Peng, Hua Li, Yirong Zhou
Summary: A unified method for direct C4-H halogenation of indoles has been successfully achieved with the assistance of anthranilic acids as suitable transient directing groups. Exclusive site selectivity and good functional group tolerance were obtained using inexpensive N-halosuccinimides as halogen sources under mild conditions. The rich functional groups in the product allow for facile construction of a diversity of nitrogen-containing heterocycles via one-step late-stage derivations.
Article
Chemistry, Organic
Ming Li, Sunday A. Akintelu, Bo Yao
Summary: The study introduces a new method for post-assembly modification of peptides via C(sp(3))-H functionalization on aliphatic side chains to access functionalized peptides as therapeutics. This method, which is well tolerant of secondary amides, allows for position-specific modification of peptides at the C-terminus.
Article
Chemistry, Organic
Ashley Dang-Nguyen, Kristine C. Legaspi, Connor T. McCarty, Diane K. Smith, Jeffrey Gustafson
Summary: We present a practical, light-mediated perfluoroalkylation method using Langlois' reagent that does not require any photocatalyst or additives. This method allows for easy functionalization of pyridones and related N-heteroarenes such as azaindole. The protocol is straightforward, utilizes readily available materials, and is compatible with both electron-neutral and -rich pyridones.
Article
Chemistry, Physical
Viktoriia Zubar, Niels Lichtenberger, Mathias Schelwies, Thomas Oeser, A. Stephen K. Hashmi, Thomas Schaub
Summary: The hydrogenation of (+)-Sclareolide to (-)-ambradiol catalyzed by a manganese pincer complex was achieved with high yield. The catalyst is easy to prepare, and the reaction conditions are relatively mild, with reproducible experimental results.
Article
Chemistry, Multidisciplinary
Robin Heckershoff, Steffen Maier, Thomas Wurm, Philipp Biegger, Kerstin Broedner, Petra Kraemer, Marvin T. Hoffmann, Lukas Eberle, Jana Stein, Frank Rominger, Matthias Rudolph, Jan Freudenberg, Andreas Dreuw, A. Stephen K. Hashmi, Uwe H. F. Bunz
Summary: The transition-metal-catalyzed cyclization of bissilylethynylated N,N'-dihydrotetraazapentacene (TIPS-TAP-H-2) into bissilylated cyclopenta[fg,qr]pentacenes is reported. Depending on the catalyst, either none, one, or two silyl groups migrate and change their positions in the formed five-membered rings. The optoelectronic properties are similar, while the packing motifs differ greatly. Control experiments and quantum chemical calculations were performed to investigate the reaction mechanism and the selectivity of the silyl shift.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Inorganic & Nuclear
Jonas F. Wunsch, Lukas Eberle, Joseph P. Mullen, Frank Rominger, Matthias Rudolph, A. Stephen K. Hashmi
Summary: We present a protocol for synthesizing air-stable gem-diaurated gold(III) compounds from 1,3-diketones using tetrachloroauric acid in a single cycloauration step. These compounds have the longest Au-Au distances among all gem-diaurated carbons. Our research demonstrates that aurophilic interactions are not necessary for stabilizing gold(III) systems.
INORGANIC CHEMISTRY
(2022)
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, Multidisciplinary
Steffen Maier, Robin Heckershoff, Nikolai Hippchen, Kerstin Broedner, Frank Rominger, Jan Freudenberg, A. Stephen K. Hashmi, Uwe H. F. Bunz
Summary: In this study, brominated pentannulated dihydrotetraazapentacenes were synthesized through gold- or palladium-catalyzed cyclization of TIPS-ethynylated dihydrotetraazaacenes, followed by Sonogashira alkynylation and Rosenmund-von Braun cyanation for post-functionalization. Characterization in organic field-effect transistors confirmed these species to act as n-type semiconductors.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Organic
Yaowen Liu, Martin C. Dietl, Chunyu Han, Matthias Rudolph, Frank Rominger, Petra Kraemer, A. Stephen K. Hashmi
Summary: Multisubstituted alkenes can be efficiently synthesized by a gold-catalyzed acyloxyalkynylation reaction, which proceeds under mild conditions and accepts a wide range of substrates, resulting in high yields.
Article
Chemistry, Physical
Taegeun Jo, Svenja Taschinski, Isaac F. Leach, Christina Bauer, A. Stephen K. Hashmi, Johannes E. M. N. Klein
Summary: In this study, a systematic investigation of protodeauration, a crucial step in gold catalysis, was conducted using isolated vinyl gold(I) complexes. The influence of substituents on gold complexes and the acidity variation of phenols as proton sources were explored. Experimental and computational results both revealed significant noncovalent interactions (NCIs) between the proton donor and vinyl gold(I) complexes, which greatly accelerated the protodeauration step.
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)