Review
Chemistry, Multidisciplinary
Sebastian Acosta-Calle, Alexander J. M. Miller
Summary: The development of catalysts has had a significant impact on science and technology, allowing for optimized reaction conditions, improved catalytic activity, and selectivity. Controlled catalysis can be achieved by manipulating the dynamics of ligands and gating substrate access to the catalyst site. The design principles for cation-controlled catalysis have been explored and various catalysts have been developed for switchable and tunable catalysis.
ACCOUNTS OF CHEMICAL RESEARCH
(2023)
Review
Chemistry, Multidisciplinary
Sebastian Acosta-Calle, Alexander J. M. Miller
Summary: Catalysis plays a crucial role in science and technology by allowing catalysts to respond to environmental changes and alter their structure and function. Controlled catalysis offers opportunities for innovation, such as optimizing performance, executing multiple reactions, and synthesizing copolymers. By controlling the dynamics of hemilabile ligands, it is possible to regulate the substrate access to catalyst sites. This approach has significant theoretical and practical implications in synthetic chemistry.
ACCOUNTS OF CHEMICAL RESEARCH
(2023)
Article
Chemistry, Multidisciplinary
Andrew M. Camp, Matthew R. Kita, P. Thomas Blackburn, Henry M. Dodge, Chun-Hsing Chen, Alexander J. M. Miller
Summary: This study successfully achieved the selective production of different internal alkene isomers using a single cation-responsive iridium catalyst, demonstrating exceptional regioselectivity and stereoselectivity under salt-free conditions. The development of new iridium pincer-crown ether catalysts played a key role in achieving cation-controlled selectivity, providing insights for catalyst development strategies based on noncovalent modifications.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Multidisciplinary
Qing-Ru Zhao, Ru Jiang, Shu-Li You
Summary: An efficient strategy was developed to access a series of axially chiral styrenes by iridium-catalyzed allylic substitution and central-to-axial chirality transfer via olefin isomerization. The method provides a broad range of axially chiral styrenes with moderate to excellent yields and enantioselectivity, offering a powerful tool in asymmetric organic synthesis.
ACTA CHIMICA SINICA
(2021)
Article
Chemistry, Multidisciplinary
Kun-Long Dai, Qi-Long Chen, Wen-Ping Xie, Ka Lu, Zhi-Bo Yan, Meng Peng, Chang-Kun Li, Yong-Qiang Tu, Tong-Mei Ding
Summary: A facile benzylic alkylation method has been developed using a newly investigated Ir-III catalyst, which provides high regioselectivity and yield of alkylated indenes and arenes from readily available alcohols. This method has potential applications in the synthesis of analogs and functional materials.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Physical
Masakazu Nambo, Koushik Ghosh, Jacky C. -H. Yim, Yasuyo Tahara, Naoto Inai, Takeshi Yanai, Cathleen M. Crudden
Summary: This paper describes the desulfonylative radical addition of tertiary alkyl groups to gem-difluoroalkenes using a photoredox Ir-catalyst. This method allows for highly stereoselective synthesis of structurally diverse (E)-fluoroalkene derivatives. The resulting (E)-fluoroalkenes can then be converted into complex fused cyclic compounds through intramolecular cyclization reactions. Control experiments and theoretical calculations support the idea that a single Ir catalyst is responsible for generating radical species from sulfones via single electron transfer and mediating Z/E isomerization via energy transfer.
Article
Chemistry, Multidisciplinary
Ryohei Kawazu, Takeru Torigoe, Yoichiro Kuninobu
Summary: New ligands have been discovered for iridium-catalyzed C(sp(3))-H borylation of aliphatic compounds. A phenanthroline-based NNSi pincer ligand has shown excellent performance and enables efficient conversion of aliphatic compounds to borylated products using an Ir/NNSi pincer catalyst system.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Organic
Wen-Wen Zhang, Bi-Jie Li
Summary: An iridium-catalyzed enantioselective alkynylation of methylene CAH bonds gamma to the amide group is developed, providing rapid access to a wide range of stereodefined alkynylated compounds in good yields and good enantioselectivities.
TETRAHEDRON LETTERS
(2021)
Article
Chemistry, Physical
Boris Sheludko, Cristina F. Castro, Chaitanya A. Khalap, Thomas J. Emge, Alan S. Goldman, Fuat E. Celik
Summary: This study synthesized two iridium complexes via immobilization of molecular precursors, which showed high selectivity in gas-phase reactions, indicating that the active site is conserved during immobilization.
Article
Chemistry, Physical
Dilawar Singh Sisodiya, Sk. Musharaf Ali, Anjan Chattopadhyay
Summary: Computational studies were conducted on the trans & RARR; cis and cis & RARR; trans isomerizations of photoresponsive azobis(benzo-15-crown-5). The photoexcited & pi; & pi;* state(S-2) of the trans isomer relaxes through the planar S-2 minimum and the planar S-2/S-1 conical intersection, both situated below the vertically excited S-2 state. The n & pi;* state (S-1) of this isomer has both planar and rotated minima, which may lead to a torsional conical intersection (S-0/S-1) geometry.
JOURNAL OF PHYSICAL CHEMISTRY A
(2023)
Article
Chemistry, Physical
Yuki Kojima, Masahiro Miura, Koji Hirano
Summary: This Cu-catalyzed reaction successfully constructs a C-sp3 chiral center with nonbenzylic and nonallylic CF3 substitution. The key to success lies in the use of an appropriate chiral bisphosphine ligand and 18-crown-6.
Article
Chemistry, Inorganic & Nuclear
Guoxia Jin, Congcong Han, Xinxue Liu, Haiying Wang, Jianping Ma
Summary: Two new functionalized platinum(II) rectangles, Pt1 and Pt2, were synthesized and studied for their selective recognition abilities for alkali-and alkaline-earth-metal cations. Pt1 selectively recognizes Na+ while Pt2 binds Mg2+. The size and conformation of the polyether receptor cavity play a crucial role in the cation selection.
INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Inorganic & Nuclear
Guoxia Jin, Congcong Han, Xinxue Liu, Haiying Wang, Jianping Ma
Summary: Two new functionalized platinum(II) rectangles, Pt1 and Pt2, were synthesized from different bridged bicarboxylate ligands. Pt1 showed selective recognition towards Na+ while Pt2 exhibited binding ability for Mg2+. These findings suggest that the size and conformation of the receptor cavity play a crucial role in cation selection.
INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Physical
Kenton E. Hicks, Andrew T. Y. Wolek, Omar K. Farha, Justin M. Notestein
Summary: This study investigates the influence of thermal pretreatments and MOF topology on the activity of Zr6O8 clusters for H-2 activation and 1-butene hydrogenation and isomerization. The results show that both thermal pretreatment and MOF topology affect the acidity of protons generated from H-2 activation and their resulting activity for olefin conversion. Additionally, the geometry of open coordination sites on individual Zr6O8 nodes influences butene hydrogenation.
Article
Chemistry, Analytical
Jin Kang, Enze Li, Li Cui, Qinglin Shao, Caixia Yin, Fangqin Cheng
Summary: This study introduces the development of a red-emitted fluorescent probe for specific detection of Li+ in biological imaging. The probe utilizes a spiropyran derivative and crown ether to achieve fluorescent emission, and has been applied in imaging of Hela cells and zebrafish. It is believed to provide an effective visualization tool for studying the biological functions of lithium ions.
SENSORS AND ACTUATORS B-CHEMICAL
(2021)
Article
Chemistry, Multidisciplinary
Dieter Sorsche, Matthias E. Miehlich, Keith Searles, Guillaume Gouget, Eva M. Zolnhofer, Skye Fortier, Chun-Hsing Chen, Michael Gau, Patrick J. Carroll, Christopher B. Murray, Kenneth G. Caulton, Marat M. Khusniyarov, Karsten Meyer, Daniel J. Mindiola
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2020)
Article
Chemistry, Inorganic & Nuclear
Tao Huang, Tayliz M. Rodriguez, Cole T. Gruninger, Daniel A. Kurtz, Aldo M. Jordan, Chun-Hsing Chen, Jillian L. Dempsey
Article
Chemistry, Multidisciplinary
Wen Shang, Roxana F. Schlam, Magali B. Hickey, Jingye Zhou, Kraig A. Wheeler, Graciela C. Diaz de Delgado, Chun-Hsing Chen, Barry B. Snider, Bruce M. Foxman
Summary: Gamma-irradiation or heating treatment of sodium trans-2-butenoate can convert it into 1-hexene-3,4-dicarboxylate, but the mechanisms for the formation of the product differ between the two methods. Furthermore, gamma-irradiation can also induce a specific trimerization reaction of sodium trans-2-butenoate.
CRYSTAL GROWTH & DESIGN
(2021)
Article
Chemistry, Multidisciplinary
Andrew M. Camp, Matthew R. Kita, P. Thomas Blackburn, Henry M. Dodge, Chun-Hsing Chen, Alexander J. M. Miller
Summary: This study successfully achieved the selective production of different internal alkene isomers using a single cation-responsive iridium catalyst, demonstrating exceptional regioselectivity and stereoselectivity under salt-free conditions. The development of new iridium pincer-crown ether catalysts played a key role in achieving cation-controlled selectivity, providing insights for catalyst development strategies based on noncovalent modifications.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Multidisciplinary
Yun Liu, Fred C. Parks, Edward G. Sheetz, Chun-Hsing Chen, Amar H. Flood
Summary: The research has created a folded capsule that can maintain high affinity in high-polarity solvents, inspired by the principle of isolating anion binding sites by proteins in aqueous environments. This new prototype has important research significance and application prospects.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Multidisciplinary
Daniel A. Kurtz, Debanjan Dhar, Noemie Elgrishi, Banu Kandemir, Sean F. McWilliams, William C. Howland, Chun-Hsing Chen, Jillian L. Dempsey
Summary: The study investigates the mechanism of hydride formation through two-electron, one-proton reactions of a family of complexes. It reveals that proton transfer rate constants are correlated with the strength of the proton source and the steric bulk of the chelating diphosphine ligands, plateauing as the reaction becomes increasingly exergonic. Mechanistic studies identify the stepwise process of hydride formation involving reduction of Co(III) species, ligand dissociation, protonation, and tautomerization.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Multidisciplinary Sciences
Pedro de Jesus Cruz, William R. Cassels, Chun-Hsing Chen, Jeffrey S. Johnson
Summary: This study reports the discovery and development of a new synthetic method that allows simultaneous control over multiple stereogenic centers for efficient preparation of pharmaceutical compounds. By merging asymmetric Michael addition and crystallization-induced diastereomer transformation, useful compounds with three contiguous stereogenic centers have been successfully synthesized.
Article
Chemistry, Inorganic & Nuclear
Alexandra H. Farquhar, Kristen E. Gardner, Sebastian Acosta-Calle, Andrew M. Camp, Chun-Hsing Chen, Alexander J. M. Miller
Summary: Palladium(II) pincer complexes with varying amine donor substituents have been prepared and studied for olefin isomerization catalysis. The introduction of a macrocycle into the pincer ligand enables switchable positional olefin isomerization by cation control. Mechanistic studies suggest the involvement of highly electrophilic Pd centers with accessible olefin binding sites in this process.
Article
Chemistry, Physical
Eric A. Assaf, Sergio Gonell, Chun-Hsing Chen, Alexander J. M. Miller
Summary: A ruthenium catalyst with a bidentate bis(carbene) ligand was prepared and studied for CO2 electroreduction. The catalyst showed high activity and efficiency at low overpotentials, with the bis(carbene) ligand playing a crucial role in CO2 activation.
Article
Chemistry, Inorganic & Nuclear
Yafei Gao, Wei-Tsung Lee, Veronica Carta, Chun-Hsing Chen, Joshua Telser, Jeremy M. M. Smith
Summary: The reduction of cobalt(II) chloride complex, Ph2B((t)BuIm)(2)Co(THF)Cl (1) with (BuN)-Bu-t equivalent to C produces the diamagnetic, square planar cobalt(I) complex Ph2B((t)BuIm)(2)Co(C equivalent to(NBu)-Bu-t)(2) (2). Complex 2, with its 16-electron configuration, is structurally related to square planar noble metal complexes. Oxidation of complex 2 results in its cobalt(II) analogue [Ph2B((t)BuIm)(2)Co(C=(NBu)-Bu-t)(2)]BPh4 (3-BPh4), which exhibits low-spin d(7) with an unpaired electron in a d(z)(2) orbital, consistent with DFT calculations. Despite its 16-electron configuration and the d(z)(2) parentage of the HOMO, complex 2 undergoes only one-electron oxidation to form complex 3.
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Inorganic & Nuclear
Quinton J. Bruch, Noah D. McMillion, Chun-Hsing Chen, Alexander J. M. Miller
Summary: Oxidative addition is a fundamental reaction in organometallic chemistry and catalysis, but examples of P-O bond activation are rare. In this study, we report the ligand-templated oxidative addition of a phosphinite P-O bond in a diphosphinito aniline compound, resulting in the formation of a (PONO)Ni((HPPr2)-Pr-i) complex after proton rearrangement. Notably, the P-O bond cleavage occurs selectively over an amine N-H bond activation. Furthermore, the ligand cannibalization is reversible, as various XPR2 reagents can readily produce different (P2ONO)NiX complexes and free HPiPr(2).
INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Inorganic & Nuclear
Tayliz M. Rodriguez, Mawuli Deegbey, Chun-Hsing Chen, Elena Jakubikova, Jillian L. Dempsey
Summary: A metal-to-ligand charge transfer with mixed intraligand character was observed in the rhenium hexakisarylisocyanide complex. The oxidation of the complex led to a dominant ligand-to-metal charge transfer mixed with intraligand transitions. The structural characterization revealed deviations from Oh geometry at the central Re ion, with larger reduction in symmetry observed for Re(II).
INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Inorganic & Nuclear
Diane P. P. Isaacs, Cole T. T. Gruninger, Tao Huang, Aldo M. M. Jordan, Genique Nicholas, Chun-Hsing Chen, Marc A. A. ter Horst, Jillian L. L. Dempsey
Summary: In the presence of a Lewis base (L), [CpW(CO)(3)](2) undergoes metal-metal bond cleavage and then undergoes disproportionation to form [CpW(CO)(3)L](+) and [CpW(CO)(3)](-) when irradiated with blue light. We found that in the presence of pyridinium tetrafluoroborate, [CpW(CO)(3)](-) reacts further to form a metal hydride complex CpW(CO)(3)H. The reaction was monitored through in situ photo H-1 NMR spectroscopy experiments and the mechanism of light-driven hydride formation was investigated by determining quantum yields of formation.
DALTON TRANSACTIONS
(2023)
Article
Chemistry, Inorganic & Nuclear
Noah D. Mcmillion, Quinton J. Bruch, Chun-Hsing Chen, Faraj Hasanayn, Alexander J. M. Miller
Summary: This study reports a class of seven-coordinate rhenium oxo complexes supported by a tetradentate ligand, and investigates the stability of possible linkage isomers and the structural characteristics of the complexes after deprotonation.
DALTON TRANSACTIONS
(2023)
Article
Chemistry, Inorganic & Nuclear
Noah D. Mcmillion, Quinton J. Bruch, Chun-Hsing Chen, Faraj Hasanayn, Alexander J. M. Miller
Summary: This study reports the synthesis and characterization of seven-coordinate rhenium oxo complexes supported by a tetradentate bipyridine carboxamide/carboxamidate ligand. The protonation and deprotonation of the ligand lead to the formation of different isomers, providing insights into the thermodynamics and bonding in pentagonal bipyramidal complexes.
DALTON TRANSACTIONS
(2023)