Article
Chemistry, Organic
Alberto Lanfranco, Polyssena Renzi, Marco Rusconi, Annamaria Deagostino
Summary: Carboranes are unique and versatile compounds with excellent stability and various chemical properties. They have found wide applications in fields such as smart materials, bioisosters, and BNCT agents. Recent studies have focused on the reactivity of carboranes under UV-visible light, leading to the preparation of functionalized carboranes and expanding their applications.
TETRAHEDRON LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Meng Chen, Jingkai Xu, Deshi Zhao, Fangxiang Sun, Songlin Tian, Deshuang Tu, Changsheng Lu, Hong Yan
Summary: This study presents a photocatalytic B-C coupling reaction for the selective functionalization of carboranes. The reaction involves the photo-induced decarboxylation of carborane carboxylic acids and generates boron vertex-centered carboranyl radicals. The reaction can be conducted under mild conditions and allows the synthesis of various functionalized carboranes, including a highly efficient blue emitter and a drug candidate for boron neutron capture therapy.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Feng-Xing Li, Xinmou Wang, Jiaxin Lin, Xiangyu Lou, Jing Ouyang, Guanwen Hu, Yangjian Quan
Summary: Selective difunctionalization of N-heterocyclic carbene (NHC) boranes with alkenes has been achieved via decatungstate and thiol synergistic catalysis. The catalytic system also allows stepwise trifunctionalization, leading to complex NHC boranes with three different functional groups which are challenging to prepare by other methods. The strong hydrogen-abstracting ability of the excited decatungstate enables the generation of boryl radicals from mono- and di-substituted boranes for realizing borane multifunctionalization. This proof-of-principle research provides a new chance for fabricating unsymmetrical boranes and developing boron-atom-economic synthesis.
Review
Chemistry, Applied
Alexander S. Budnikov, Igor B. Krylov, Olga M. Mulina, Dmitry A. Lapshin, Alexander O. Terent'ev
Summary: In the last decade, free radicals have been widely used for the functionalization of unsaturated compounds, particularly heterocycles, through intermolecular addition of heteroatom-centered radicals. Recent literature analysis shows a trend towards the use of electrochemistry and photoredox-catalysis for free radical generation. However, there is a need for stronger experimental support and mechanistic studies to predict optimal reaction conditions.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Chemistry, Physical
Feiyu Han, Dongsheng Zhang, Sofia Salli, Jiani Ye, Yongwang Li, Federico Rosei, Xiao-Dong Wen, Hans Niemantsverdriet, Emma Richards, Ren Su
Summary: In this study, a copper-modified graphitic carbon nitride was used to synthesize alpha-haloketones from aromatic olefins under mild reaction conditions. This novel photosynthetic strategy offers environmental sustainability, high selectivity, and stability.
Article
Chemistry, Multidisciplinary
Qiang Liu, Bei-Bei Zhang, He Sheng, Sen Qiao, Zhi-Xiang Wang, Xiang-Yu Chen
Summary: The visible-light-induced photoreduction of carborane phosphonium salts under blue light irradiation provides a simple and effective method for accessing carbon-centered carboranyl radicals without the use of transition metals and photocatalysts. The utility of this method is demonstrated by the successful preparation of carborane-oxindole-pharmaceutical hybrids through radical cascade reactions. Computational and experimental studies suggest that the carbon-centered carboranyl radicals are generated through single-electron transfer of photoactive charge-transfer complexes between the salts and the additive potassium acetate.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Organic
Siyu Liang, Kaijie Wei, Yajun Lin, Tuming Liu, Dian Wei, Bing Han, Wei Yu
Summary: This paper describes two new visible-light-promoted radical reactions of alpha-azido amides. N-aryl alpha-azido tertiary amides were transformed into aminyl radicals through reduction of the azido group, followed by N-to-N aryl migration to form alpha-anilinyl-functionalized amides; on the other hand, alpha-azido secondary amides reacted with ethanol and i-Pr2NEt to yield imidazolinone products.
Article
Chemistry, Multidisciplinary
Fangxiang Sun, Shuaimin Tan, Hou-Ji Cao, Jingkai Xu, Vladimir I. Bregadze, Deshuang Tu, Changsheng Lu, Hong Yan
Summary: This research proposes a new molecular design strategy for achieving AIE properties by combining three-dimensional aromatic boron clusters of carboranes with vinyl group(s). A efficient synthesis method for boron cluster-based AIEgens is developed.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Review
Chemistry, Inorganic & Nuclear
Krzysztof Fink, Mariusz Uchman
Summary: Boron cluster compounds are inorganic compounds with unique structures and properties that show promising antimicrobial activity and low sensitivity to pathogen resistance mechanisms. Their derivatives are effective against both standard and multi-drug resistant strains of pathogens.
COORDINATION CHEMISTRY REVIEWS
(2021)
Article
Chemistry, Inorganic & Nuclear
Chaofan Sun, Ju-You Lu, Jian Lu
Summary: Efficient Pd-catalyzed regioselective B(6)-H phosphorization of nido-carboranes via cascade deboronation/B-H activation with various phosphines using 3-methylpyridine or isoquinoline as a directing group in combination with pyridine ligands has been developed, affording unprecedented B(6)-phosphinated nido-carborane derivatives with high selectivity in a simple one-pot process.
INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Martin Hejda, Daniel Duvinage, Enno Lork, Antonin Lycka, Zdenck Cernosek, Jan Machacek, Sergey Makarov, Sergey Ketkov, Stefan Mebs, Libor Dostal, Jens Beckmann
Summary: The aryltellurenyl cation and the weakly coordinating carborane anion form an isolable ion pair complex, in which the Bronsted acidity of the formally hydridic B-H bonds is dramatically increased, leading to a proton transfer reaction at slightly elevated temperatures. The isolation of zwitterionic isomers further confirms the electrophilic activation of B-H bonds in the carborane moiety.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Multidisciplinary
Manjur O. Akram, John R. Tidwell, Jason L. Dutton, Caleb D. Martin
Summary: The synthesis of a single site neutral Lewis superacid, tris(ortho-carboranyl)borane (BoCb(3)), was achieved in one pot from commercially available materials. It was confirmed to be a Lewis superacid due to its high fluoride ion affinity (FIA), and exhibited stronger Lewis acidity compared to widely used fluorinated aryl boranes, as evidenced by the Gutmann-Beckett method and adducts with Lewis bases. The unusually high Lewis acidity can be rationalized by the electron-withdrawing effect of ortho-carborane and lack of pi-delocalization of the LUMO. Catalytic studies demonstrated that BoCb(3) is a superior catalyst for promoting C-F bond functionalization reactions compared to tris(pentafluorophenyl)borane [B(C6F5)(3)].
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Multidisciplinary Sciences
Tobias Hartwig Bunning, Luigi Panza, Abdel Kareem Azab, Barbara Muz, Silvia Fallarini, Daniela Imperio
Summary: Boron Neutron Capture Therapy (BNCT) shows promise in treating non-curable cancers, with a new boron compound being discovered to selectively accumulate in tumor tissue. Hypoxia poses a challenge in cancer treatment, but a new compound exhibits toxicity in multiple myeloma cells and consistent intracellular boron accumulation.
Article
Chemistry, Multidisciplinary
Alessandro Marotta, Hao Fang, Callum E. Adams, Kailey Sun Marcus, Constantin G. Daniliuc, John J. Molloy
Summary: Operationally simple strategies using visible light and a simple Lewis base are disclosed for the facile activation of α-halo boronic esters, leading to the construction of versatile E-allylic boronic esters via intermolecular addition to styrenes. This activation method can be strategically merged with selective energy transfer catalysis for the complimentary stereodivergent synthesis of Z-allylic boronic esters.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Medicinal
Katia Messner, Billy Vuong, Geoffrey K. Tranmer
Summary: This review discusses the history of boron's early use in drugs and the use of boron functional groups in medicinal chemistry. It highlights critical developments from these functional groups and showcases the application of boron in prodrugs, softdrugs, and nanocarriers.
Article
Chemistry, Multidisciplinary
Derek Rhoades, Arnold L. Rheingold, Bert W. O'Malley, Jin Wang
Summary: This paper describes atom and step economical total syntheses of spliceosome modulating natural products pladienolides A and B. A strategic functionalization of an unsaturated macrolide precursor enabled the most concise syntheses of these natural products to date, providing convenient, flexible access to stereodefined macrolides for medicinal chemistry explorations. The utility of this synthetic route is further demonstrated by the enantioselective total synthesis of H3B-8800, a semisynthetic pladienolide-derived spliceosome modulator undergoing clinical trials for hematological malignancies.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Inorganic & Nuclear
Alex E. Carpenter, Curtis E. Moore, Arnold L. Rheingold, Joshua S. Figueroa
Summary: The reactivity of HCo(CNArMes2)(4) towards olefin substrates involves formation of new complexes and loss of isocyanide ligands, indicating a propensity for hydride migration. Additionally, the complex can engage in hydrogen-atom transfer and protolytic dihydrogen evolution reactions.
Article
Chemistry, Inorganic & Nuclear
Andrew M. Romine, Matthew J. Demer, Milan Gembicky, Arnold L. Rheingold, Keary M. Engle
Summary: Tetrahydrothiophene-functionalized N, S-heterocyclic carbene palladium(II) complexes were synthesized through an unexpected rearrangement using palladium(II) trifluoroacetate instead of other palladium(II) compounds, and their catalytic capabilities in C-C coupling reactions were demonstrated.
Article
Chemistry, Multidisciplinary
Guobi Li, Rhett Smith, Milan Gembicky, Arnold L. Rheingold, John D. Protasiewicz
Summary: In this study, a di-hypervalent iodine compound was synthesized using a bulky 1,4-di-iodobenzene with four para-Bu-t-C6H4 group substituents. The compound underwent cyclization under mild conditions to form a dicyclic di-iodonium di-triflate salt. The introduction of para-tert-butyl groups improved the solubility of the compounds, making them more suitable for applications as recyclable reagents, materials precursors, and Lewis acids.
CHEMICAL COMMUNICATIONS
(2022)
Article
Chemistry, Inorganic & Nuclear
Zakary T. Ekstrom, Arnold L. Rheingold, John D. Protasiewicz
Summary: Two bis(benzoxaphosphole)s were synthesized and characterized, with one compound exhibiting flexibility in structure and blue fluorescence, while the other compound showed no significant emission due to the quenching ability of ferrocene in its excited state.
PHOSPHORUS SULFUR AND SILICON AND THE RELATED ELEMENTS
(2022)
Article
Chemistry, Organic
Joshua L. Martin, Girish C. Sati, Tanmay Malakar, Jessica Hatt, Paul M. Zimmerman, John Montgomery
Summary: A novel mode of reactivity involving a dioxolenium ion as a key intermediate that promotes both glycosylation and glycosyl exchange pathways has been discovered through experimental and computational mechanistic studies. By modifying the catalyst structure, it is possible to selectively favor one pathway, leading to improved multicomponent iterative couplings and glycosyl exchange processes.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Physical
Muyuan Zhao, Jayvic C. Jimenez, Chunlai Wang, Guanchun Rui, Tingrui Ma, Chenwei Lu, Arnold L. Rheingold, Ruipeng Li, Lei Zhu, Genevieve Sauve
Summary: This study explores the fluorination of a zinc(II) complex to increase intermolecular pi-pi stacking interactions and improve electron mobility and organic photovoltaic performance.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Chemistry, Inorganic & Nuclear
Jorge A. Garduno, David S. Glueck, Ritchie E. Hernandez, Joshua S. Figueroa, Arnold L. Rheingold
Summary: In this study, it was discovered through a series of experiments that under specific conditions, the weakly coordinating fluorinated tetraarylborate anion can react with a platinum cation and weak acid water at room temperature, decomposing three bonds and producing new compounds.
Article
Chemistry, Physical
Thomas Louis-Goff, Huu Vinh Trinh, Eileen Chen, Arnold L. Rheingold, Christian Ehm, Jakub Hyvl
Summary: An efficient catalytic difluorocarbenation reaction has been developed to synthesize 1,1-difluorocyclopropanes using an organobismuth complex as the catalyst and TMS-CF3 as the difluorocarbene source. The reaction exhibits wide substrate scope and good robustness, generating the desired products with high selectivity. The mechanism of difluorocarbene generation and the high selectivity have been studied through experiments and theoretical calculations.
Article
Chemistry, Physical
Harrison A. Mills, Christopher G. Jones, Kierstyn P. Anderson, Austin D. Ready, Peter I. Djurovich, Saeed I. Khan, J. Nathan Hohman, Hosea M. Nelson, Alexander M. Spokoyny
Summary: In this study, sterically invariant carborane-based chalcogenols were used as ligands for the formation of photoluminescent copper(I)-based metal-organic chalcogenolate assemblies (MO-CHAs). By precisely tuning the carborane dipole through isomer changes, control over MOCHA morphology and regulation of photophysical properties were achieved. Additionally, microcrystal electron diffraction (MicroED) was shown to be a powerful tool for elucidating metal chalcogenide structures, revealing a novel Cu4Se4 geometry in one isolated material.
CHEMISTRY OF MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Sloane Evariste, Alexandra M. Harrison, Sunandan Sarkar, Arnold L. Rheingold, Barry D. Dunietz, Joachim W. Heinicke, Emalyn Delgado Rosario, Sungwoon Yoon, Thomas S. Teets, John D. Protasiewicz
Summary: 2-R-1H-1,3-Benzazaphospholes are an interesting class of heterocycles with P=C bonds. This study presents the synthesis and structural characterization of a new R-BAP (R = 2,2'-dithiophene) and compares its photoluminescence with two previously reported R-BAPs (R,R' = Me and R = 2-thiophene). The thiophene derivatives exhibit significant fluorescence, while the methyl-substituted analogue shows weak emission.
Article
Chemistry, Inorganic & Nuclear
Lihua Liu, Daniel Mendoza-Espinosa, Mauricio Quiroz-Guzman, Arnold L. Rheingold, Tracy A. Hanna, Gobinda Saha, Liming Tang, Yanhui Chen, Megan Gilbert, Abhirup Dutta, Alexandru D. Asandei
Summary: A series of methylene-bridged bisphenol ligands were synthesized and reacted with TiCl4, CpTiCl3, or Ti(OiPr)4 to form corresponding complexes, which were characterized and found to exhibit good reactivity in polymerization reactions.
Article
Chemistry, Inorganic & Nuclear
Preston M. Miura-Akagi, Timothy W. Chapp, Wesley Y. Yoshida, Glenn P. A. Yap, Arnold L. Rheingold, Russell P. Hughes, Matthew F. Cain
Summary: Dearomatization of N-Dipp-substituted benzazaphosphole 2 with HCl produced 1-Cl, which could be further substituted by halide sources to obtain the other members of the P halogenated series. Characterization of these P-heterocycles (1) was performed using multinuclear NMR spectroscopy, elemental analysis, and X-ray crystallography. The study also explored the reaction of 1-Br/I with [Pt(P(t-Bu)3)2], resulting in the formation of Pt(I)-Pt(I) dimers 4-Br/I, and the addition of 1-F to Pt(PPh3)4, leading to the coordination compound Pt(1-F)(PPh3)2.
Article
Chemistry, Multidisciplinary
Harrison A. Mills, Samihat Rahman, Rachel Zigelstein, Hao Xu, Bryton R. Varju, Timothy P. Bender, Mark W. B. Wilson, Dwight S. Seferos
Summary: Conjugated macromolecules have a rich history in chemistry. Researchers have synthesized a new type of molecular dyads, consisting of sequence-defined oligomers and small-molecule acceptors. By controlling the sequence and length of the oligomers, the impact on the transfer efficiency of photoexcited states has been explored, highlighting the significance in studying light harvesting and photocatalysis.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Biochemistry & Molecular Biology
Mariola Flores-Rivera, Jose Carmona-Negron, Arnold Rheingold, Enrique Melendez
Summary: 3-ferrocenyl-estra-1,3,5(10)-triene-17-one (2), [Fe(C5H5)(C24H25O3)], crystallizes in monoclinic space group C2. The Cp rings adopt a nearly eclipsed conformation, and the Cp plane is tilted with respect to the substituted phenyl plane. Weak intermolecular interactions such as C-H···π and C-H···O were analyzed. Density functional theory studies revealed a rotational barrier for the C3-O1 bond. Fluorescence quenching and in silico docking studies suggest that human serum albumin forms a complex via van der Waals and hydrogen bonding interactions.
