1
|
Das P, Grinalds NJ, Ghiviriga I, Abboud KA, Dobrzycki Ł, Xue J, Castellano RK. Dicyanorhodanine-Pyrrole Conjugates for Visible Light-Driven Quantitative Photoswitching in Solution and the Solid State. J Am Chem Soc 2024; 146:11932-11943. [PMID: 38629510 DOI: 10.1021/jacs.4c00983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2024]
Abstract
Small molecule photoswitches capable of toggling between two distinct molecular states in response to light are versatile tools to monitor biological processes, control photochemistry, and design smart materials. In this work, six novel dicyanorhodanine-based pyrrole-containing photoswitches are reported. The molecular design avails both the Z and E isomers from synthesis, where each can be isolated using chromatographic techniques. Inter- and intramolecular hydrogen bonding (H-bonding) interactions available to the E and Z isomers, respectively, uniquely impart thermal stability to each isomer over long time periods. Photoisomerization could be assessed by solution NMR and UV-vis spectroscopic techniques along with complementary ground- and excited-state computational studies, which show good agreement. Quantitative E → Z isomerization occurs upon 523 nm irradiation of the parent compound (where R = H) in solution, whereas Z → E isomerization using 404 nm irradiation offers a photostationary state (PSS) ratio of 84/16 (E/Z). Extending the π-conjugation of the pyrrole unit (where R = p-C6H4-OMe) pushes the maximum absorption to the yellow-orange region of the visible spectrum and allows bidirectional quantitative isomerization with 404 and 595 nm excitation. Comparator molecules have been prepared to report how the presence or absence of H-bonding affects the photoswitching behavior. Finally, studies of the photoswitches in neat films and photoinactive polymer matrices reveal distinctive structural and optical properties of the Z and E isomers and ultimately afford reversible photoswitching to spectrally unique PSSs using visible light sources including the Sun.
Collapse
Affiliation(s)
- Parag Das
- Department of Chemistry, University of Florida, P. O. Box 117200, Gainesville, Florida 32611, United States
| | - Nathan J Grinalds
- Department of Materials Science and Engineering, University of Florida, P. O. Box 116400, Gainesville, Florida 32611, United States
| | - Ion Ghiviriga
- Department of Chemistry, University of Florida, P. O. Box 117200, Gainesville, Florida 32611, United States
| | - Khalil A Abboud
- Department of Chemistry, University of Florida, P. O. Box 117200, Gainesville, Florida 32611, United States
| | - Łukasz Dobrzycki
- Department of Chemistry, University of Florida, P. O. Box 117200, Gainesville, Florida 32611, United States
| | - Jiangeng Xue
- Department of Materials Science and Engineering, University of Florida, P. O. Box 116400, Gainesville, Florida 32611, United States
| | - Ronald K Castellano
- Department of Chemistry, University of Florida, P. O. Box 117200, Gainesville, Florida 32611, United States
| |
Collapse
|
2
|
Hu X, Zhu Z, Li Z, Adili A, Odagi M, Abboud KA, Seidel D. Catalytic Enantioselective [4+2] Cycloadditions of Salicylaldehyde Acetals with Enol Ethers. Angew Chem Int Ed Engl 2024; 63:e202315759. [PMID: 38055210 DOI: 10.1002/anie.202315759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Revised: 11/28/2023] [Accepted: 11/30/2023] [Indexed: 12/07/2023]
Abstract
A readily accessible conjugate-base-stabilized carboxylic acid (CBSCA) catalyst facilitates highly enantioselective [4+2] cycloaddition reactions of salicylaldehyde-derived acetals and cyclic enol ethers, resulting in the formation of polycyclic chromanes with oxygenation in the 2- and 4-positions. Stereochemically more complex products can be obtained from racemic enol ethers. Spirocyclic products are also accessible.
Collapse
Affiliation(s)
- Xiaojun Hu
- Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, FL 32611, USA
| | - Zhengbo Zhu
- Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, FL 32611, USA
| | - Zhongzheng Li
- Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, FL 32611, USA
| | - Alafate Adili
- Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, FL 32611, USA
| | - Minami Odagi
- Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, FL 32611, USA
- Department of Biotechnology and Life Science, Graduate School of Technology, Tokyo University of Agriculture and Technology, 2-24-16, Naka-cho, Koganei city, 184-8588, Tokyo, Japan
| | - Khalil A Abboud
- Center for X-ray Crystallography, Department of Chemistry, University of Florida, Gainesville, FL 32611, USA
| | - Daniel Seidel
- Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, FL 32611, USA
| |
Collapse
|
3
|
Dutta S, Kim JH, Bhatt K, Rickertsen DRL, Abboud KA, Ghiviriga I, Seidel D. Alicyclic-Amine-Derived Imine-BF 3 Complexes: Easy-to-Make Building Blocks for the Synthesis of Valuable α-Functionalized Azacycles. Angew Chem Int Ed Engl 2024; 63:e202313247. [PMID: 37909921 PMCID: PMC10835740 DOI: 10.1002/anie.202313247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 10/26/2023] [Accepted: 10/29/2023] [Indexed: 11/03/2023]
Abstract
A new strategy to access α-functionalized alicyclic amines via their corresponding imine-BF3 complexes is reported. Isolable imine-BF3 complexes, readily prepared via dehydrohalogenation of N-bromoamines in a base-promoted/18-crown-6 catalyzed process followed by addition of boron trifluoride etherate, undergo reactions with a wide range of organometallic nucleophiles to afford α-functionalized azacycles. Organozinc and organomagnesium nucleophiles add at ambient temperatures, obviating the need for cryogenic conditions. In situ preparation of imine-BF3 complexes provides access to α-functionalized morpholines and piperazines directly from their parent amines in a single operation. α-Functionalized morpholines can be elaborated further, for instance by installing a second substituent in the α'-position.
Collapse
Affiliation(s)
- Subhradeep Dutta
- Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, FL 32611, USA
| | - Jae Hyun Kim
- Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, FL 32611, USA
- College of Pharmacy, Chung-Ang University, Seoul, 06974, Republic of Korea
| | - Kamal Bhatt
- Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, FL 32611, USA
| | - Dillon R L Rickertsen
- Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, FL 32611, USA
| | - Khalil A Abboud
- Center for X-ray Crystallography, Department of Chemistry, University of Florida, Gainesville, FL 32611, USA
| | - Ion Ghiviriga
- Center for NMR Spectroscopy, Department of Chemistry, University of Florida, Gainesville, FL 32611, USA
| | - Daniel Seidel
- Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, FL 32611, USA
| |
Collapse
|
4
|
Beauchamp AM, Chakraborty J, Ghiviriga I, Abboud KA, Lester DW, Veige AS. Ring Expansion Alkyne Metathesis Polymerization. J Am Chem Soc 2023; 145:22796-22802. [PMID: 37812163 DOI: 10.1021/jacs.3c08717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
The synthesis, characterization, and preliminary activity of an unprecedented tethered alkylidyne tungsten complex for ring expansion alkyne metathesis polymerization (REAMP) are reported. The tethered alkylidyne 7 is generated rapidly by combining alkylidyne W(CtBu)(CH2tBu)(O-2,6-i-Pr2C6H3)2 (6) with 1 equiv of an yne-ol proligand (5). Characterized by NMR studies and nuclear Overhauser effect spectroscopy, complex 7 is a dimer. Each metal center contains a tungsten-carbon triple bond tethered to the metal center via an alkoxide ligand. The polymerization of the strained cycloalkyne 3,8-didodecyloxy-5,6-dihydro-11,12-didehydrodibenzo[a,e]-[8]annulene, 8, to generate cyclic polymers was demonstrated. Size exclusion chromatography (SEC) and intrinsic viscosity (η) measurements confirm the polymer's cyclic topology.
Collapse
Affiliation(s)
- Andrew M Beauchamp
- Department of Chemistry, Center for Catalysis, University of Florida, Gainesville, Florida 32611, United States
| | - Jhonti Chakraborty
- Department of Chemistry, Center for Catalysis, University of Florida, Gainesville, Florida 32611, United States
| | - Ion Ghiviriga
- Department of Chemistry, Center for NMR Spectroscopy, University of Florida, Gainesville, Florida 32611, United States
| | - Khalil A Abboud
- Department of Chemistry, Center for Catalysis, University of Florida, Gainesville, Florida 32611, United States
| | - Daniel W Lester
- Polymer Characterization Research Technology Platform, University of Warwick, Coventry CV4 7AL, U.K
| | - Adam S Veige
- Department of Chemistry, Center for Catalysis, University of Florida, Gainesville, Florida 32611, United States
| |
Collapse
|
5
|
Hale AR, Abboud KA, Christou G. Synthetic Factors Determining the Curvature and Nuclearity of the Giant Mn 70 and Mn 84 Clusters with a Torus Structure of ∼4 nm Diameter. Inorg Chem 2023; 62:6020-6031. [PMID: 37015039 DOI: 10.1021/acs.inorgchem.2c04520] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/06/2023]
Abstract
New members of the Mn70 and Mn84 torus-like cluster family have been prepared from a hybrid comproportionation-alcoholysis reaction of [Mn12O12(O2CR)16(H2O)4] in alcohol in the presence of R'CO2H with NnBuMnO4 or MnII salts as initiators. Reactions using MeCO2H in nPrOH or nBuOH gave [Mn70O60(O2CMe)70(OnPr)20(nPrOH)18.5(H2O)21.5] (3) and [Mn70O60(O2CMe)70(OH)3(OnBu)17(nBuOH)7.5(H2O)32.5] (4), respectively, whereas EtCO2H in nPrOH gave [Mn84O72(O2CEt)84(OnPr)24(nPrOH)16(H2O)32] (5). They consist of alternating near-linear [Mn3(μ3-O)4]+ and distorted-cubane [Mn4(μ3-O)2(μ3-OR)2]6+ units bridged by syn,syn-μ-RCO2- and μ3-O2- groups and overall are [Mn14]5 and [Mn14]6 oligomers, the repeating unit containing two Mn3 and two Mn4 units. 3/4/5 possess external diameters (including organic ligands) of 4.0/4.1/4.6 nm, respectively, and crystallize as supramolecular nanotubes but with different packing arrangements. Considering all Mn70/Mn84 tori now available, we conclude that the Mn70 vs Mn84 nuclearity is determined by the relative bulk of the carboxylates vs the alkoxides, their increasing bulk favoring Mn84 and Mn70, respectively, with carboxylates larger than acetate giving Mn84. Alternating current (ac) magnetic susceptibility studies revealed frequency-dependent χ″M signals below ∼2.4 K, indicating 3-5 to be new members of the giant [Mn14]n torus family of giant single-molecule magnets (SMMs), in which Mn84 and Mn70 are the largest homometallic Mn/O clusters and SMMs to date.
Collapse
Affiliation(s)
- Ashlyn R Hale
- Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, United States
| | - Khalil A Abboud
- Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, United States
| | - George Christou
- Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, United States
| |
Collapse
|
6
|
Jakhar VK, Shen YH, Hyun SM, Esper AM, Ghiviriga I, Abboud KA, Lester DW, Veige AS. Improved Trianionic Pincer Ligand Synthesis for Cyclic Polymer Catalysts. Organometallics 2023. [DOI: 10.1021/acs.organomet.3c00060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/31/2023]
|
7
|
Adili A, Webster JP, Zhao C, Mallojjala SC, Romero-Reyes MA, Ghiviriga I, Abboud KA, Vetticatt MJ, Seidel D. Mechanism of a Dually Catalyzed Enantioselective Oxa-Pictet-Spengler Reaction and the Development of a Stereodivergent Variant. ACS Catal 2023; 13:2240-2249. [PMID: 37711191 PMCID: PMC10501388 DOI: 10.1021/acscatal.2c05484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Enantioselective oxa-Pictet-Spengler reactions of tryptophol with aldehydes proceed under weakly acidic conditions utilizing a combination of two catalysts, an indoline HCl salt and a bisthiourea compound. Mechanistic investigations revealed the roles of both catalysts and confirmed the involvement of oxocarbenium ion intermediates, ruling out alternative scenarios. A stereochemical model was derived from density functional theory calculations, which provided the basis for the development of a highly enantioselective stereodivergent variant with racemic tryptophol derivatives.
Collapse
Affiliation(s)
- Alafate Adili
- Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| | - John-Paul Webster
- Department of Chemistry, Binghamton University, Binghamton, New York 13902, United States
| | - Chenfei Zhao
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, United States
| | | | - Moises A Romero-Reyes
- Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| | - Ion Ghiviriga
- Center for NMR Spectroscopy, Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| | - Khalil A Abboud
- Center for X-ray Crystallography, Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| | - Mathew J Vetticatt
- Department of Chemistry, Binghamton University, Binghamton, New York 13902, United States
| | - Daniel Seidel
- Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| |
Collapse
|
8
|
Shen YH, Ghiviriga I, Abboud KA, Schanze KS, Veige AS. iClick synthesis of network metallopolymers. Dalton Trans 2022; 51:18520-18527. [PMID: 36444537 DOI: 10.1039/d2dt01624a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Described is an approach to preparing the first iClick network metallopolymers with porous properties. Treating digoldazido complex 2-AuN3 with trigoldacetylide 3-AuPPh3 or 3-AuPEt3, trialkyne 3-H, tetragoldacetylide 4-AuPPh3, or tetraalkyne 4-H in CH2Cl2 affords five iClick network metallopolymers 5-AuPPh3, 5-AuPEt3, 5-H, 6-AuPPh3, and 6-H. Confirmation of the iClick network metallopolymers comes from FTIR, 13C solid-state cross-coupling magic angle spinning (CPMAS) NMR spectroscopy, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and nitrogen and CO2 sorption analysis. Employing model complexes 7-AuPPh3, 7-AuPEt3, 7-H, 8-AuPPh3, and 8-H provides structural insights due to the insolubility of iClick network metallopolymers.
Collapse
Affiliation(s)
- Yu-Hsuan Shen
- University of Florida, Department of Chemistry, Center for Catalysis, P.O. Box 117200, Gainesville, FL, 32611, USA.
| | - Ion Ghiviriga
- University of Florida, Department of Chemistry, Center for Catalysis, P.O. Box 117200, Gainesville, FL, 32611, USA.
| | - Khalil A Abboud
- University of Florida, Department of Chemistry, Center for Catalysis, P.O. Box 117200, Gainesville, FL, 32611, USA.
| | - Kirk S Schanze
- University of Texas at San Antonio, Department of Chemistry, One UTSA Circle, San Antonio, TX 78249, USA
| | - Adam S Veige
- University of Florida, Department of Chemistry, Center for Catalysis, P.O. Box 117200, Gainesville, FL, 32611, USA.
| |
Collapse
|
9
|
Lee KHK, Aebersold L, Peralta JE, Abboud KA, Christou G. Synthesis, Structure, and Magnetic Properties of an Fe 36 Dimethylarsinate Cluster: The Largest "Ferric Wheel". Inorg Chem 2022; 61:17256-17267. [PMID: 36251497 DOI: 10.1021/acs.inorgchem.2c02841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The synthesis and characterization of a high-nuclearity FeIII/O/arsinate cluster is reported within the salt [Fe36O12(OH)6(O2AsMe2)63(O2CH)3(H2O)6](NO3)12 (1). The compound was prepared from the reaction of Fe(NO3)3·9H2O, dimethylarsinic acid (Me2AsO2H), and triethylamine in a 1:2:4 molar ratio in acetonitrile. The Fe36 cation of 1 is an unprecedented structural type consisting of nine Fe4 butterfly units of two types, three {FeIII4(μ3-O)2} units A, and six {FeIII4(μ3-O)(μ3-OH)} units B, linked by multiple bridging Me2AsO2- groups into an Fe36 triangular wheel/loop with C3 crystallographic and D3 virtual symmetry that looks like a guitar plectrum. The unusual structure has been rationalized on the basis of the different curvatures of units A and B, the presence of intra-Fe36 hydrogen bonding, and the tendency of Me2AsO2- groups to favor μ3-bridging modes. The cations stack into supramolecular nanotubes parallel to the crystallographic c axis and contain badly disordered solvent and NO3- anions. The cation of 1 is the highest-nuclearity "ferric wheel" to date and also the highest-nuclearity Fe/O cluster of any structural type with a single contiguous Fe/O core. Variable-temperature direct-current magnetic susceptibility data and alternating-current in-phase magnetic susceptibility data indicate that the cation of 1 possesses an S = 0 ground state and dominant antiferromagnetic interactions. The Fe2 pairwise Ji,j couplings were estimated by the combined use of a magnetostructural correlation for high-nuclearity FeIII/oxo clusters and density functional theory calculations using broken-symmetry methods and the Green's function approach. The three methods gave satisfyingly similar Ji,j values and allowed the identification of spin-frustration effects and the resulting relative spin-vector alignments and thus rationalization of the S = 0 ground state of the cation.
Collapse
Affiliation(s)
- Kenneth Hong Kit Lee
- Department of Chemistry, University of Florida, Gainesville, Florida32611-7200, United States
| | - Lucas Aebersold
- Department of Physics and Science of Advanced Materials, Central Michigan University, Mount Pleasant, Michigan48859, United States
| | - Juan E Peralta
- Department of Physics and Science of Advanced Materials, Central Michigan University, Mount Pleasant, Michigan48859, United States
| | - Khalil A Abboud
- Department of Chemistry, University of Florida, Gainesville, Florida32611-7200, United States
| | - George Christou
- Department of Chemistry, University of Florida, Gainesville, Florida32611-7200, United States
| |
Collapse
|
10
|
Jakhar VK, Esper AM, Ghiviriga I, Abboud KA, Ehm C, Veige AS. Isolation of an Elusive Phosphametallacyclobutadiene and Its Role in Reversible Carbon−Carbon Bond Cleavage. Angew Chem Int Ed Engl 2022; 61:e202203073. [PMID: 35536109 PMCID: PMC9296546 DOI: 10.1002/anie.202203073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Indexed: 11/11/2022]
Abstract
The reactivity of phosphaalkynes, the isolobal and isoelectronic congeners to alkynes, with metal alkylidyne complexes is explored in this work. Treating the tungsten alkylidyne [t BuOCO]W≡Ct Bu(THF)2 (1) with phosphaalkyne (10) results in the formation of [O2 C(t BuC=)W{η2 -(P,C)-P≡C-Ad}(THF)] (13-t BuTHF ) and [O2 C(AdC=)W{η2 -(P,C)-P≡C-t Bu}(THF)] (13-AdTHF ); derived from the formal reductive migratory insertion of the alkylidyne moiety into a W-Carene bond. Analogous to alkyne metathesis, a stable phosphametallacyclobutadiene complex [t BuOCO]W[κ2 -C(t Bu)PC(Ad)] (14) forms upon loss of THF from the coordination sphere of either 13-t BuTHF or 13-AdTHF . Remarkably, the C-C bonds reversibly form/cleave with the addition or removal of THF from the coordination sphere of the formal tungsten(VI) metal center, permitting unprecedented control over the transformation of a tetraanionic pincer to a trianionic pincer and back. Computational analysis offers thermodynamic and electronic reasoning for the reversible equilibrium between 13-t Bu/AdTHF and 14.
Collapse
Affiliation(s)
- Vineet K. Jakhar
- Department of Chemistry University of Florida Center for Catalysis P.O. Box 117200 Gainesville FL 32611 USA
| | - Alec M. Esper
- Department of Chemistry University of Florida Center for Catalysis P.O. Box 117200 Gainesville FL 32611 USA
| | - Ion Ghiviriga
- Department of Chemistry University of Florida Center for Catalysis P.O. Box 117200 Gainesville FL 32611 USA
| | - Khalil A. Abboud
- Department of Chemistry University of Florida Center for Catalysis P.O. Box 117200 Gainesville FL 32611 USA
| | - Christian Ehm
- Dipartimento di Scienze Chimiche Università di Napoli Federico II Via Cintia 80126 Napoli Italy
| | - Adam S. Veige
- Department of Chemistry University of Florida Center for Catalysis P.O. Box 117200 Gainesville FL 32611 USA
| |
Collapse
|
11
|
Hale AR, Lott ME, Peralta JE, Foguet-Albiol D, Abboud KA, Christou G. Magnetic Properties of High-Nuclearity Fe x-oxo ( x = 7, 22, 24) Clusters Analyzed by a Multipronged Experimental, Computational, and Magnetostructural Correlation Approach. Inorg Chem 2022; 61:11261-11276. [PMID: 35816698 DOI: 10.1021/acs.inorgchem.2c01371] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The synthesis, structure, and magnetic properties of three related iron(III)-oxo clusters are reported, [Fe7O3(O2CPh)9(mda)3(H2O)] (1), [Fe22O14(OH)3(O2CMe)21(mda)6](ClO4)2 (2), and [Fe24O15(OH)4(OEt)(O2CMe)21(mda)7](ClO4)2 (3), where mdaH2 is N-methyldiethanolamine. 1 was prepared from the reaction of [Fe3O(O2CPh)6(H2O)3](NO3) with mdaH2 in a 1:2 ratio in MeCN, whereas 2 and 3 were prepared from the reaction of FeCl3/NaO2CMe/mdaH2 in a 2:∼13:2 ratio and FeCl3/NaO2CMe/mdaH2/pyridine in a 2:∼13:2:25 ratio, respectively, both in EtOH. The core of 1 consists of a central octahedral FeIII ion held within a nonplanar Fe6 loop by three μ3-O2- and three μ2-RO- arms from the three mda2- chelates. The cores of the cations of 2 and 3 consist of an A:B:A three-layer topology, in which a central Fe6 (2) or Fe8 (3) layer B is sandwiched between two Fe8 layers A. The A layers structurally resemble 1 with the additional Fe added at the center to retain virtual C3 symmetry. The central Fe6 layer B of 2 consists of a {Fe4(μ4-O)2(μ3-OH)2}6+ cubane with an Fe on either side attached to cubane O2- ions, whereas that of 3 has the same cubane but with an {Fe3(μ3-O)(μ-OH)} unit attached on one side and a single Fe on the other. Variable-temperature dc and ac magnetic susceptibility studies revealed dominant antiferromagnetic coupling in all complexes leading to ground-state spins of S = 5/2 for 1 and S = 0 for 2 and 3. All Fe2 pairwise exchange parameters (Jij) for 1-3 were estimated by two independent methods: density functional theory (DFT) calculations using broken symmetry methods and a magnetostructural correlation previously developed for high-nuclearity FeIII/O complexes. The two approaches gave satisfyingly similar Jij values, and the latter allowed rationalization of the experimental ground states by identification of the spin frustration effects operative and the resultant relative spin vector alignments at each FeIII ion.
Collapse
Affiliation(s)
- Ashlyn R Hale
- Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, Unites States
| | - Megan E Lott
- Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, Unites States
| | - Juan E Peralta
- Department of Physics and Science of Advanced Materials, Central Michigan University, Mount Pleasant, Michigan 48859, United States
| | - Dolos Foguet-Albiol
- Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, Unites States
| | - Khalil A Abboud
- Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, Unites States
| | - George Christou
- Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, Unites States
| |
Collapse
|
12
|
Hale AR, Aebersold LE, Peralta JE, Foguet-Albiol D, Abboud KA, Christou G. Analysis of spin frustration in an FeIII7 cluster using a combination of computational, experimental, and magnetostructural correlation methods. Polyhedron 2022. [DOI: 10.1016/j.poly.2022.116045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
13
|
Jakhar VK, Esper AM, Ghiviriga I, Abboud KA, Ehm C, Veige AS. Isolation of an Elusive Phosphametallacyclobutadiene and Its Role in Reversible Carbon−Carbon Bond Cleavage. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202203073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Vineet K. Jakhar
- Department of Chemistry University of Florida Center for Catalysis P.O. Box 117200 Gainesville FL 32611 USA
| | - Alec M. Esper
- Department of Chemistry University of Florida Center for Catalysis P.O. Box 117200 Gainesville FL 32611 USA
| | - Ion Ghiviriga
- Department of Chemistry University of Florida Center for Catalysis P.O. Box 117200 Gainesville FL 32611 USA
| | - Khalil A. Abboud
- Department of Chemistry University of Florida Center for Catalysis P.O. Box 117200 Gainesville FL 32611 USA
| | - Christian Ehm
- Dipartimento di Scienze Chimiche Università di Napoli Federico II Via Cintia 80126 Napoli Italy
| | - Adam S. Veige
- Department of Chemistry University of Florida Center for Catalysis P.O. Box 117200 Gainesville FL 32611 USA
| |
Collapse
|
14
|
Das Gupta S, Thuijs AE, Fisher EG, Abboud KA, Christou G. Mn II/III and Ce III/IV Units Supported on an Octahedral Molecular Nanoparticle of CeO 2. Inorg Chem 2022; 61:6392-6402. [PMID: 35191310 DOI: 10.1021/acs.inorgchem.1c03719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The preparation of three new heterometallic clusters [Ce6Mn12O17(O2CPh)26] (1), [Ce10Mn14O24(O2CPh)32] (2), and [Ce23Mn20O48(OH)2(tbb)46(H2O)4](NO3)2 (3; tbb- = 4-tBu-benzoate) is reported. They all possess unprecedented structures with a common feature being the presence of an octahedral CeIV-oxo core: a Ce6 in 1, two edge-fused Ce6 giving a Ce10 bioctahedron in 2, or a larger Ce19 octahedron in 3. Complex 1 is the first Ce6 cluster with a central μ6-O2-. 2 and the cation of 3 are molecular nanoparticles of CeO2 (ceria) because they possess the fluorite structure of bulk ceria and are thus ultrasmall ceria nanoparticles in molecular form. The {Ce19O32} octahedral subunit of the cation of 3 had been predicted from density functional theory studies to be one of the stable fragments of the CeO2 lattice, but has never been previously synthesized in molecular chemistry. Around the Ce/O core of 1-3 is an incomplete monolayer of Mnn ions disposed as four Mn3, two Mn7, and four Mn5 units, respectively. This represents a clear structural similarity with composite (phase-separated) CeO2/MnOx mixtures where at high Ce:Mn ratios the Mn atoms segregate on the surface of CeO2 phases. Variable-temperature dc and ac magnetic susceptibility studies have revealed S = 2, S = 1/2, and S = 3/2 ground states for 1-3, respectively. Fitting of the 5.0-300 K dc data for 1 to a two-J model for an asymmetrical V-shaped Mn3 unit with no interaction between the end MnIII ions gave an excellent fit with the following values: J1 = 5.2(3) cm-1, J2 = -7.4(3) cm-1, and g = 1.96(2).
Collapse
Affiliation(s)
- Sayak Das Gupta
- Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, United States
| | - Annaliese E Thuijs
- Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, United States
| | - Ethan G Fisher
- Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, United States
| | - Khalil A Abboud
- Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, United States
| | - George Christou
- Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, United States
| |
Collapse
|
15
|
Aponick A, Dahiya G, Abboud KA. Tuning StackPhim Ligands: Applications in Enantioselective Borylation and Alkynylation. SYNTHESIS-STUTTGART 2022. [DOI: 10.1055/a-1730-2473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
AbstractHere we present a new stack ligand with a modified imidazoline backbone prepared from cyclohexanediamine. This new stack ligand, Cy-StackPhim, has been found to complement the parent StackPhim ligand in an enantioselective borylation reaction. Additionally, a correlation between the nature of substituents on the imidazoline ring and the substituents on the electrophile is also discussed.
Collapse
Affiliation(s)
- Aaron Aponick
- Center for Heterocyclic Compounds, Department of Chemistry, University of Florida
| | - Gaurav Dahiya
- Center for Heterocyclic Compounds, Department of Chemistry, University of Florida
| | - Khalil A. Abboud
- Center for X-ray Crystallography, Department of Chemistry, University of Florida
| |
Collapse
|
16
|
Mannchen MD, Ghiviriga I, Abboud KA, Grenning AJ. 1,2,4-Trifunctionalized Cyclohexane Synthesis via a Diastereoselective Reductive Cope Rearrangement and Functional Group Interconversion Strategy. Org Lett 2021; 23:8804-8809. [PMID: 34719933 DOI: 10.1021/acs.orglett.1c03310] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Polyfunctionalized cyclohexanes are privileged scaffolds in drug discovery. Reported herein is a method for synthesizing 1,2,4-trifunctionalized cyclohexanes via diastereoselective reductive Cope rearrangement. The scaffolds obtained can be derivatized by orthogonal functional group interconversion to cyclohexanes bearing a 1-amide, 2-branched arylallyl, and variable 4-functional group.
Collapse
Affiliation(s)
- Michael D Mannchen
- Department of Chemistry, University of Florida, Gainesville, Florida 32603, United States
| | - Ion Ghiviriga
- Center for NMR Spectroscopy, Department of Chemistry, University of Florida, Gainesville, Florida 32603, United States
| | - Khalil A Abboud
- Center for X-ray Crystallography, Department of Chemistry, University of Florida, Gainesville, Florida 32603, United States
| | - Alexander J Grenning
- Department of Chemistry, University of Florida, Gainesville, Florida 32603, United States
| |
Collapse
|
17
|
Russell-Webster B, Lopez-Nieto J, Abboud KA, Christou G. Phosphorus-based ligand effects on the structure and radical scavenging ability of molecular nanoparticles of CeO 2. Dalton Trans 2021; 50:15524-15532. [PMID: 34643207 DOI: 10.1039/d1dt02667d] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Two new CeIV/O2- clusters, (pyH)8[Ce10O4(OH)4(O3PPh)12(NO3)12] (1) and [Ce6O4(OH)4(O2PPh2)4(O2CtBu)8] (2), have been prepared that contain P-based ligands for the first time. They were obtained from the reaction of (NH4)2[Ce(NO3)6], PhPO3H2 or Ph2PO2H, and tBuCO2H in a 2 : 1 : 2 molar ratio in pyridine/MeOH (10 : 1 mL). Both compounds contain a {Ce6O4(OH)4} face-capped octahedral core, with 1 containing an additional four CeIV on the outside to give a supertetrahedral Ce10 topology; the {Ce6O8} unit is the smallest recognizable fragment of the fluorite structure of CeO2. The HO˙ radical scavenging activities of 1 and 2 were measured by UV/vis spectral monitoring of methylene blue oxidation by HO˙ radicals in the presence and absence of the Ce/O clusters, and the results compared with those for larger Ce24 and Ce38 molecular nanoparticles of CeO2 prepared in previous work. 1 and 2 are both very poor HO˙ radical scavengers compared with Ce24 and Ce38, a result that is consistent with reports in the literature that PO43- ions inhibit the radical scavenging ability of traditional CeO2 nanoparticles and putatively assigned to PO43- binding to the surface.
Collapse
Affiliation(s)
| | - Javi Lopez-Nieto
- Department of Chemistry, University of Florida, Gainesville, FL 32611-7200, USA,
| | - Khalil A Abboud
- Department of Chemistry, University of Florida, Gainesville, FL 32611-7200, USA,
| | - George Christou
- Department of Chemistry, University of Florida, Gainesville, FL 32611-7200, USA,
| |
Collapse
|
18
|
Pham L, Cao TS, Abboud KA, Christou G. New family of Ln9Mn4 (Ln = Gd, Tb, Dy) and Y9Mn4 clusters from the use of methyl-2-pyridyl-ketone oxime in heterometallic Mn chemistry. Polyhedron 2021. [DOI: 10.1016/j.poly.2021.115462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
19
|
Mandal U, Ghiviriga I, Abboud KA, Lester DW, Veige AS. Double Tethered Metallacyclobutane Catalyst for Cyclic Polymer Synthesis. J Am Chem Soc 2021; 143:17276-17283. [PMID: 34618432 DOI: 10.1021/jacs.1c08806] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
This work outlines an approach to creating a catalyst for cyclic polymer synthesis using readily available materials in only one or two steps. Combining commercially available molybdenum-alkylidene 1 with two equivalents of ene-ol proligand 2 rapidly produces, in quantitative yield (1H NMR spectroscopy), the double tethered metallacyclobutane complex 3. Characterized by variable temperature NMR studies and nuclear Overhauser effect spectroscopy (NOESY) experiments, complex 3 exhibits fluxional behavior in solution. Determined by single crystal X-ray diffraction, the solid-state structure of complex 3 reveals metrical parameters indicating that the metallacyclobutane is not predicted to undergo rapid retro-cycloaddition. However, complex 3 is a precatalyst for the polymerization of norbornene to produce cyclic polynorbornene. An NMR spectrum of a test polymerization indicates that only a small fraction of the precatalyst is activated upon exposure to monomer. Quantifying the active catalyst is possible by measuring vinyl resonances that appear in the 1H NMR spectrum. The vinyl resonances are attributable to the release of one of the tethers upon norbornene addition. Confirmation of the polymer cyclic topology comes from gel permeation chromatography (GPC), dynamic light scattering (DLS), and intrinsic viscosity (η) measurements. The double tethered metallacyclobutane complex is a novel design for catalytic cyclic polymer synthesis. The synthetic approach suggests that catalyst tuning is possible by a choice of the commercial alkylidene and alteration of the ene-ol proligand.
Collapse
Affiliation(s)
- Ushnish Mandal
- Department of Chemistry, Center for Catalysis, University of Florida, P.O. Box 117200, Gainesville, Florida 32611, United States
| | - Ion Ghiviriga
- Department of Chemistry, Center for NMR Spectroscopy, University of Florida, P.O. Box 117200, Gainesville, Florida 32611, United States
| | - Khalil A Abboud
- Department of Chemistry, Center for Catalysis, University of Florida, P.O. Box 117200, Gainesville, Florida 32611, United States
| | - Daniel W Lester
- Polymer Characterization Research Technology Platform, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Adam S Veige
- Department of Chemistry, Center for Catalysis, University of Florida, P.O. Box 117200, Gainesville, Florida 32611, United States
| |
Collapse
|
20
|
Ondari ME, Klosin J, Kruper WR, Lysenko I, Thomas PJ, Cheng K, Abboud KA, Kruper WJ. Diol-Ritter Reaction: Regio- and Stereoselective Synthesis of Protected Vicinal Aminoalcohols and Mechanistic Aspects of Diol Monoester Disproportionation. J Org Chem 2021; 87:2063-2074. [PMID: 34581583 DOI: 10.1021/acs.joc.1c01475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The well-known epoxide-Ritter reaction generally affords oxazolines with poor to average regioselectivity. Herein, a mechanism-based study of the less known diol-Ritter reaction has provided a highly regioselective procedure for the synthesis of 1-vic-amido-2-esters from either terminal epoxides or 1,2-diols via Lewis acid-catalyzed monoesterification. When treated with a stoichiometric Lewis acid catalyst (BF3), these diol monoesters form dioxonium cation intermediates that are ring-opened with nitrile nucleophiles to form nitrilium intermediates, which undergo rapid and irreversible hydration to give the desired amidoesters. Diester byproduct formation is irreversible and appears to occur through disproportionation of diol monoester. With chiral epoxide starting materials, the formation of amidoester occurs with retention of configuration and no apparent erosion of optical purity as determined by single-crystal X-ray analyses and chiral chromatography, respectively. The direct access to chiral vic-amidoesters is especially practical with regard to the synthesis of antibacterial oxazolidinone analogues of the Zyvox antimicrobial family.
Collapse
Affiliation(s)
- Mark E Ondari
- Corteva Agriscience, 1710 Building, Midland, Michigan 48674, United States
| | - Jerzy Klosin
- Corporate R&D, The Dow Chemical Company, 1776 Building, Midland, Michigan 48674, United States
| | - William R Kruper
- Corteva Agriscience, 1710 Building, Midland, Michigan 48674, United States
| | - Ivan Lysenko
- Michigan State University, St Andrews, Midland, Michigan 48674, United States
| | | | - Kevin Cheng
- Michigan State University, St Andrews, Midland, Michigan 48674, United States
| | - Khalil A Abboud
- Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| | - William J Kruper
- Michigan State University, St Andrews, Midland, Michigan 48674, United States
| |
Collapse
|
21
|
Jakhar V, Pal D, Ghiviriga I, Abboud KA, Lester DW, Sumerlin BS, Veige AS. Correction to "Tethered Tungsten-Alkylidenes for the Synthesis of Cyclic Polynorbornene via Ring Expansion Metathesis: Unprecedented Stereoselectivity and Trapping of Key Catalytic Intermediates". J Am Chem Soc 2021; 143:15472. [PMID: 34516116 DOI: 10.1021/jacs.1c08915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
22
|
Shen YH, Esper AM, Ghiviriga I, Abboud KA, Schanze KS, Ehm C, Veige AS. SPAAC iClick: progress towards a bioorthogonal reaction in-corporating metal ions. Dalton Trans 2021; 50:12681-12691. [PMID: 34545891 DOI: 10.1039/d1dt02626g] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Combining strain-promoted azide-alkyne cycloaddition (SPAAC) and inorganic click (iClick) reactivity provides access to metal 1,2,3-triazolates. Experimental and computational insights demonstrate that iClick reactivity of the tested metal azides (LM-N3, M = Au, W, Re, Ru and Pt) depends on the accessibility of the azide functionality rather than electronic effects imparted by the metal. SPAAC iClick reactivity with cyclooctyne is observed when the azide functionality is sterically unencumbered, e.g. [Au(N3)(PPh3)] (Au-N3), [W(η3-allyl)(N3)(bpy)(CO)2] (W-N3), and [Re(N3)(bpy)(CO)3] [bpy = 2,2'-bipyridine] (Re-N3). Increased steric bulk and/or preequilibria with high activation barriers prevent SPAAC iClick reactivity for the complexes [Ru(N3)(Tp)(PPh3)2] [Tp = tris(pyrazolyl)borate] (Ru-N3), [Pt(N3)(CH3)(PiPr3)2] [iPr = isopropyl] (Pt(II)-N3), and [Pt(N3)(CH3)3]4 ((PtN3)4). Based on these computational insights, the SPAAC iClick reactivity of [Pt(N3)(CH3)3(P(CH3)3)2] (Pt(IV)-N3) was successfully predicted.
Collapse
Affiliation(s)
- Yu-Hsuan Shen
- University of Florida, Department of Chemistry, Center for Catalysis, P.O. Box 117200, Gainesville, FL, 32611, USA.
| | - Alec M Esper
- University of Florida, Department of Chemistry, Center for Catalysis, P.O. Box 117200, Gainesville, FL, 32611, USA.
| | - Ion Ghiviriga
- University of Florida, Department of Chemistry, Center for Catalysis, P.O. Box 117200, Gainesville, FL, 32611, USA.
| | - Khalil A Abboud
- University of Florida, Department of Chemistry, Center for Catalysis, P.O. Box 117200, Gainesville, FL, 32611, USA.
| | - Kirk S Schanze
- University of Texas at San Antonio, Department of Chemistry, One UTSA Circle, San Antonio, TX 78249, USA
| | - Christian Ehm
- Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Via Cintia, 80126 Napoli, Italy.
| | - Adam S Veige
- University of Florida, Department of Chemistry, Center for Catalysis, P.O. Box 117200, Gainesville, FL, 32611, USA.
| |
Collapse
|
23
|
Abstract
A simple one-pot procedure enables the sequential, regioselective, and diastereoselective introduction of the same or two different substituents to the α- and α'-positions of unprotected azacycles. Aryl, alkyl, and alkenyl substituents are introduced via their corresponding organolithium compounds. The scope of this transformation includes pyrrolidines, piperidines, azepanes, and piperazines.
Collapse
Affiliation(s)
- Daniel A. Valles
- Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| | - Subhradeep Dutta
- Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| | - Anirudra Paul
- Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| | - Khalil A. Abboud
- Center for X-ray Crystallography, Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| | - Ion Ghiviriga
- Center for NMR Spectroscopy, Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| | - Daniel Seidel
- Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| |
Collapse
|
24
|
Abstract
The supramolecular polymerization of 2,11-dithia[3.3]paracyclophanes through self-complementary intermolecular and transannular amide hydrogen bonding is presented. An n → π* interaction between the amide hydrogen bonding units and the central bridging atom results from the single-point exchange of a carbon atom for a sulfur atom. This orbital donor-acceptor interaction can be strengthened by oxidizing the sulfide to a sulfone which acts to shorten the donor···acceptor distance and increase orbital overlap. Experimental signatures of the increased n → π* interaction include larger isodesmic polymerization elongation constants in solution, changes in characteristic bond stretching frequencies, and geometric/structural changes evaluated by X-ray crystallography. The experimental data are supported by extensive computational investigations of both assembling and nonassembling 2,11-dithia[3.3]paracyclophanes as well as a rationally designed model system to confirm the role of stereoelectronic effects on supramolecular polymer assembly.
Collapse
Affiliation(s)
- Will R Henderson
- George & Josephine Butler Polymer Research Laboratory, Center for Macromolecular Science & Engineering, Department of Chemistry, University of Florida, P.O. Box 117200 Gainesville, Florida 32611-7200, United States
| | - Guancen Liu
- George & Josephine Butler Polymer Research Laboratory, Center for Macromolecular Science & Engineering, Department of Chemistry, University of Florida, P.O. Box 117200 Gainesville, Florida 32611-7200, United States
| | - Khalil A Abboud
- George & Josephine Butler Polymer Research Laboratory, Center for Macromolecular Science & Engineering, Department of Chemistry, University of Florida, P.O. Box 117200 Gainesville, Florida 32611-7200, United States
| | - Ronald K Castellano
- George & Josephine Butler Polymer Research Laboratory, Center for Macromolecular Science & Engineering, Department of Chemistry, University of Florida, P.O. Box 117200 Gainesville, Florida 32611-7200, United States
| |
Collapse
|
25
|
Russell‐Webster B, Lopez‐Nieto J, Abboud KA, Christou G. Truly Monodisperse Molecular Nanoparticles of Cerium Dioxide of 2.4 nm dimensions: A {Ce
100
O
167
} Cluster. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202103110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
| | - Javi Lopez‐Nieto
- Department of Chemistry University of Florida Gainesville FL 32611-7200 USA
| | - Khalil A. Abboud
- Department of Chemistry University of Florida Gainesville FL 32611-7200 USA
| | - George Christou
- Department of Chemistry University of Florida Gainesville FL 32611-7200 USA
| |
Collapse
|
26
|
Russell-Webster B, Lopez-Nieto J, Abboud KA, Christou G. Truly Monodisperse Molecular Nanoparticles of Cerium Dioxide of 2.4 nm dimensions: A {Ce 100 O 167 } Cluster. Angew Chem Int Ed Engl 2021; 60:12591-12596. [PMID: 33768655 DOI: 10.1002/anie.202103110] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Indexed: 12/14/2022]
Abstract
Ultra-small nanoparticles of CeO2 obtained in molecular form, so-called molecular nanoparticles, have been limited to date to a family whose largest member is of nuclearity Ce40 with a {Ce40 O58 } core atom count. Herein we report that a synthetic procedure has been developed to the cation [Ce100 O149 (OH)18 (O2 CPh)60 (PhCO2 H)12 (H2 O)20 ]16+ , a member with a much higher Ce100 nuclearity and a {Ce100 O167 } core that is more akin to the smallest ceria nanoparticles. Its crystal structure reveals it to possess a 2.4 nm size and high D2d symmetry, and it has also allowed identification of core surface features including facet composition, the presence and location of Ce3+ and H+ (i.e. HO- ) ions, and the binding modes of the ligand monolayer of benzoate, benzoic acid, and water ligands.
Collapse
Affiliation(s)
| | - Javi Lopez-Nieto
- Department of Chemistry, University of Florida, Gainesville, FL, 32611-7200, USA
| | - Khalil A Abboud
- Department of Chemistry, University of Florida, Gainesville, FL, 32611-7200, USA
| | - George Christou
- Department of Chemistry, University of Florida, Gainesville, FL, 32611-7200, USA
| |
Collapse
|
27
|
Chear NJY, León F, Sharma A, Kanumuri SRR, Zwolinski G, Abboud KA, Singh D, Restrepo LF, Patel A, Hiranita T, Ramanathan S, Hampson AJ, McMahon LR, McCurdy CR. Exploring the Chemistry of Alkaloids from Malaysian Mitragyna speciosa (Kratom) and the Role of Oxindoles on Human Opioid Receptors. J Nat Prod 2021; 84:1034-1043. [PMID: 33635670 PMCID: PMC8693998 DOI: 10.1021/acs.jnatprod.0c01055] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Ten indole and oxindole alkaloids (1-10) were isolated from the freshly collected leaves of Malaysian Mitragyna speciosa (Kratom). The chemical structures of these compounds were established on the basis of extensive 1D and 2D NMR and HRMS data analysis. The spectroscopic data of mitragynine oxindole B (4) are reported herein for the first time. The spatial configuration of mitragynine oxindole B (4) was confirmed by single-crystal X-ray diffraction. Simultaneous quantification of the isolated alkaloids in the M. speciosa leaf specimens collected from different locations in the northern region of Peninsular Malaysia was also performed using UPLC-MS/MS. The oxindole alkaloids (1-4) and the indole alkaloid (10) were assessed for binding affinity at opioid receptors. Corynoxine (1) showed high binding affinity to μ-opioid receptors with a Ki value of 16.4 nM. Further, corynoxine (1) was 1.8-fold more potent than morphine in rats subjected to a nociceptive hot plate assay. These findings have important implications for evaluating the combined effects of the minor oxindole alkaloids in the overall therapeutic activity of M. speciosa.
Collapse
Affiliation(s)
- Nelson Jeng-Yeou Chear
- Centre for Drug Research, Universiti Sains Malaysia, 11800 Minden, Penang, Malaysia
- Department of Medicinal Chemistry, College of Pharmacy, University of Florida, Gainesville, Florida 32610, United States
| | - Francisco León
- Department of Medicinal Chemistry, College of Pharmacy, University of Florida, Gainesville, Florida 32610, United States
| | - Abhisheak Sharma
- Department of Pharmaceutics, College of Pharmacy, University of Florida, Gainesville, Florida 32610, United States
- Translational Drug Development Core, Clinical and Translational Sciences Institute, University of Florida, Gainesville, Florida 32610, United States
| | - Siva Rama Raju Kanumuri
- Department of Pharmaceutics, College of Pharmacy, University of Florida, Gainesville, Florida 32610, United States
- Translational Drug Development Core, Clinical and Translational Sciences Institute, University of Florida, Gainesville, Florida 32610, United States
| | - Grant Zwolinski
- Department of Medicinal Chemistry, College of Pharmacy, University of Florida, Gainesville, Florida 32610, United States
| | - Khalil A Abboud
- Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| | - Darshan Singh
- Centre for Drug Research, Universiti Sains Malaysia, 11800 Minden, Penang, Malaysia
| | - Luis F Restrepo
- Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, Florida 32610, United States
| | - Avi Patel
- Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, Florida 32610, United States
| | - Takato Hiranita
- Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, Florida 32610, United States
| | - Surash Ramanathan
- Centre for Drug Research, Universiti Sains Malaysia, 11800 Minden, Penang, Malaysia
| | - Aidan J Hampson
- Division of Therapeutics and Medical Consequences, National Institute on Drug Abuse, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - Lance R McMahon
- Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, Florida 32610, United States
| | - Christopher R McCurdy
- Department of Medicinal Chemistry, College of Pharmacy, University of Florida, Gainesville, Florida 32610, United States
- Department of Pharmaceutics, College of Pharmacy, University of Florida, Gainesville, Florida 32610, United States
- Translational Drug Development Core, Clinical and Translational Sciences Institute, University of Florida, Gainesville, Florida 32610, United States
| |
Collapse
|
28
|
Ghosh T, Marbey J, Wernsdorfer W, Hill S, Abboud KA, Christou G. Exchange-biased quantum tunnelling of magnetization in a [Mn 3] 2 dimer of single-molecule magnets with rare ferromagnetic inter-Mn 3 coupling. Phys Chem Chem Phys 2021; 23:8854-8867. [PMID: 33876045 DOI: 10.1039/d0cp06611g] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A covalently-linked dimer of two single-molecule magnets (SMMs), [Mn6O(O2CMe)6(1,3-ppmd)3](ClO4)2, has been synthesized from the reaction of [Mn3O(O2CMe)6(py)3](ClO4) with 1,3-phenylene-bis(pyridin-2-ylmethanone) dioxime (1,3-ppmdH2). It contains two [MnIII3O]+7 triangular units linked by three 1,3-ppmd2- groups into an [Mn3]2 dimer with D3 symmetry. Solid-state dc and ac magnetic susceptibility measurements showed that each Mn3 subunit retains its properties as an SMM with an S = 6 ground state. Magnetization vs. dc field sweeps on a single crystal reveal hysteresis loops below 1.3 K exhibiting exchange-biased quantum tunnelling of magnetization (QTM) steps with a bias field of +0.06 T. This is the first example of a dimer of SMMs showing a positive exchange bias of the QTM steps in the hysteresis loops, and it has therefore been subjected to a detailed analysis. Simulation of the loops determines that each Mn3 unit is exchange-coupled with its neighbour primarily through the 1,3-ppmd2- linkers, confirming a weak ferromagnetic inter-Mn3 interaction of J12≈ +6.5 mK (Ĥ = -2Jŝi·ŝj convention). High-frequency EPR studies of a microcrystalline powder sample enable accurate determination of the zero-field splitting parameters of the uncoupled Mn3 SMMs, while also confirming the weak exchange interaction between the two SMMs within each [Mn3]2 dimer. The combined results emphasize the ability of designed covalent linkers to generate inter-SMM coupling of a particular sign and relative magnitude, and thus the ability of such linkers to modulate the quantum physics. As such, this work supports the feasibility of using designed covalent linkers to develop molecular oligomers of SMMs, or other magnetic molecules, as multi-qubit systems and/or other components of new quantum technologies.
Collapse
Affiliation(s)
- Tuhin Ghosh
- Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, USA.
| | | | | | | | | | | |
Collapse
|
29
|
Soler M, Mahalay P, Wernsdorfer W, Lubert-Perquel D, Huffman JC, Abboud KA, Hill S, Christou G. Extending the family of reduced [Mn12O12(O2CR)16(H2O)x]n− complexes, and their sensitivity to environmental factors. Polyhedron 2021. [DOI: 10.1016/j.poly.2020.114968] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
30
|
Jakhar V, Pal D, Ghiviriga I, Abboud KA, Lester DW, Sumerlin BS, Veige AS. Tethered Tungsten-Alkylidenes for the Synthesis of Cyclic Polynorbornene via Ring Expansion Metathesis: Unprecedented Stereoselectivity and Trapping of Key Catalytic Intermediates. J Am Chem Soc 2021; 143:1235-1246. [PMID: 33417768 DOI: 10.1021/jacs.0c12248] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
This report describes an approach for preparing tethered tungsten-imido alkylidene complexes featuring a tetra-anionic pincer ligand. Treating the tungsten alkylidyne [tBuOCO]W≡CtBu(THF)2 (1) with isocyanates (RNCO; R = tBu, Cy, and Ph) leads to cycloaddition occurring exclusively at the C═N bond to generate the tethered tungsten-imido alkylidenes (6-NR). Unanticipated intermediates reveal themselves, including the discovery of [(O2CtBuC═)W(η2-(N,C)-RNCO)(THF)] (11-R) and an unprecedented decarbonylation product [(tBuOCO)W(≡NR)(tBuCCO)] (14-R), on the pathway to the formation of 6-NR. Complex 11-R is kinetically stable for sterically bulky isocyanate R = tBu (11-tBu) and is isolated and characterized by single-crystal X-ray diffraction. Finally, adding to the short list of catalysts capable of ring expansion metathesis polymerization (REMP), complexes 6-NR and 11-tBu are active for the stereoselective synthesis of cyclic polynorbornene.
Collapse
Affiliation(s)
- Vineet Jakhar
- Department of Chemistry, Center for Catalysis, University of Florida, P.O. Box 117200, Gainesville, Florida 32611, United States
| | - Digvijayee Pal
- George and Josephine Butler Polymer Research Laboratory, Center for Macromolecular Science and Engineering, University of Florida, P.O. Box 117200, Gainesville, Florida 32611, United States
| | - Ion Ghiviriga
- Department of Chemistry, Center for Catalysis, University of Florida, P.O. Box 117200, Gainesville, Florida 32611, United States
| | - Khalil A Abboud
- Department of Chemistry, Center for Catalysis, University of Florida, P.O. Box 117200, Gainesville, Florida 32611, United States
| | - Daniel W Lester
- Polymer Characterization Research Technology Platform, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Brent S Sumerlin
- George and Josephine Butler Polymer Research Laboratory, Center for Macromolecular Science and Engineering, University of Florida, P.O. Box 117200, Gainesville, Florida 32611, United States
| | - Adam S Veige
- Department of Chemistry, Center for Catalysis, University of Florida, P.O. Box 117200, Gainesville, Florida 32611, United States.,George and Josephine Butler Polymer Research Laboratory, Center for Macromolecular Science and Engineering, University of Florida, P.O. Box 117200, Gainesville, Florida 32611, United States
| |
Collapse
|
31
|
Jiang G, Zhang P, Ratnayake R, Yang G, Zhang Y, Zuo R, Powell M, Huguet-Tapia JC, Abboud KA, Dang LH, Teplitski M, Paul V, Xiao R, Ahammad KH, Zaman U, Hu Z, Cao S, Luesch H, Ding Y. Fungal Epithiodiketopiperazines Carrying α,β-Polysulfide Bridges from Penicillium steckii YE, and Their Chemical Interconversion. Chembiochem 2021; 22:416-422. [PMID: 32816319 PMCID: PMC7895331 DOI: 10.1002/cbic.202000403] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 08/19/2020] [Indexed: 11/09/2022]
Abstract
Some fungal epithiodiketopiperazine alkaloids display α,β-polysulfide bridges alongside diverse structural variations. However, the logic of their chemical diversity has rarely been explored. Here, we report the identification of three new (2, 3, 8) and five known (1, 4-7) epithiodiketopiperazines of this subtype from a marine-derived Penicillium sp. The structure elucidation was supported by multiple spectroscopic analyses. Importantly, we observed multiple nonenzymatic interconversions of these analogues in aqueous solutions and organic solvents. Furthermore, the same biosynthetic origin of these compounds was supported by one mined gene cluster. The dominant analogue (1) demonstrated selective cytotoxicity to androgen-sensitive prostate cancer cells and HIF-depleted colorectal cells and mild antiaging activities, linking the bioactivity to oxidative stress. These results provide crucial insight into the formation of fungal epithiodiketopiperazines through chemical interconversions.
Collapse
Affiliation(s)
- Guangde Jiang
- Department of Medicinal Chemistry, Center for Natural Products, Drug Discovery and Development, University of Florida, Gainesville, FL, 32610, USA
| | - Peilan Zhang
- Department of Medicinal Chemistry, Center for Natural Products, Drug Discovery and Development, University of Florida, Gainesville, FL, 32610, USA
| | - Ranjala Ratnayake
- Department of Medicinal Chemistry, Center for Natural Products, Drug Discovery and Development, University of Florida, Gainesville, FL, 32610, USA
| | - Guang Yang
- Department of Medicinal Chemistry, Center for Natural Products, Drug Discovery and Development, University of Florida, Gainesville, FL, 32610, USA
| | - Yi Zhang
- Department of Medicinal Chemistry, Center for Natural Products, Drug Discovery and Development, University of Florida, Gainesville, FL, 32610, USA
| | - Ran Zuo
- Department of Medicinal Chemistry, Center for Natural Products, Drug Discovery and Development, University of Florida, Gainesville, FL, 32610, USA
| | - Magan Powell
- Department of Medicinal Chemistry, Center for Natural Products, Drug Discovery and Development, University of Florida, Gainesville, FL, 32610, USA
| | - José C Huguet-Tapia
- Department of Plant Pathology, University of Florida, Gainesville, 32611, FL, USA
| | - Khalil A Abboud
- Department of Chemistry, University of Florida, Gainesville, 32611, FL, USA
| | - Long H Dang
- Department of Medicinal Chemistry, Center for Natural Products, Drug Discovery and Development, University of Florida, Gainesville, FL, 32610, USA
- Department of Medicine, University of Florida, Gainesville, 32610, FL, USA
| | - Max Teplitski
- Soil and Water Science Department, University of Florida, Gainesville, 32610, FL, USA
| | - Valerie Paul
- Smithsonian Marine Station at Ft., Pierce, 701 Seaway Drive, Ft. Pierce, 34949, FL, USA
| | - Rui Xiao
- Departments of Aging and Geriatric Research, Pharmacology and Therapeutics, Center for Smell and Taste, University of Florida, Gainesville, 32610, FL, USA
| | - K H Ahammad
- Department of Medicinal Chemistry, Center for Natural Products, Drug Discovery and Development, University of Florida, Gainesville, FL, 32610, USA
| | - Uz Zaman
- Department of Pharmaceutical Sciences, Daniel K. Inouye College of Pharmacy, University of Hawai'i at Hilo, Hilo, Hawaii, 96720, USA
| | - Zhenquan Hu
- Warshel Institute for Computational Biology, The Chinese University of Hong Kong,Shenzhen, Guangdong, 518172, P. R. China
- School of Chemistry and Materials Science, University of Science and Technology of China, Hefei, Anhui, 230026, P. R. China
| | - Shugeng Cao
- Department of Pharmaceutical Sciences, Daniel K. Inouye College of Pharmacy, University of Hawai'i at Hilo, Hilo, Hawaii, 96720, USA
| | - Hendrik Luesch
- Department of Medicinal Chemistry, Center for Natural Products, Drug Discovery and Development, University of Florida, Gainesville, FL, 32610, USA
| | - Yousong Ding
- Department of Medicinal Chemistry, Center for Natural Products, Drug Discovery and Development, University of Florida, Gainesville, FL, 32610, USA
| |
Collapse
|
32
|
Mitchell KJ, Goodsell JL, Russell-Webster B, Twahir UT, Angerhofer A, Abboud KA, Christou G. Expansion of the Family of Molecular Nanoparticles of Cerium Dioxide and Their Catalytic Scavenging of Hydroxyl Radicals. Inorg Chem 2021; 60:1641-1653. [DOI: 10.1021/acs.inorgchem.0c03133] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Kylie J. Mitchell
- Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, United States
| | - Justin L. Goodsell
- Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, United States
| | - Bradley Russell-Webster
- Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, United States
| | - Umar T. Twahir
- Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, United States
| | - Alexander Angerhofer
- Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, United States
| | - Khalil A. Abboud
- Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, United States
| | - George Christou
- Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, United States
| |
Collapse
|
33
|
Lee KHK, Peralta JE, Abboud KA, Christou G. Iron(III)-Oxo Cluster Chemistry with Dimethylarsinate Ligands: Structures, Magnetic Properties, and Computational Studies. Inorg Chem 2020; 59:18090-18101. [PMID: 33291879 DOI: 10.1021/acs.inorgchem.0c02554] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A program has been initiated to develop FeIII/oxo cluster chemistry with the "pseudocarboxylate" ligand dimethylarsinate (Me2AsO2-) for comparison with the well investigated FeIII/oxo/carboxylate cluster area. The synthesis and characterization of three polynuclear FeIII complexes are reported, [Fe12O4(O2CtBu)8(O2AsMe2)17(H2O)3]Cl3 (1), Na2[Fe12Na2O4(O2AsMe2)20(NO3)6(Me2AsO2H)2(H2O)4](NO3)6 (2), and [Fe3(O2AsMe2)6(Me2AsO2H)2(hqn)2](NO3) (3), where hqnH is 8-hydroxyquinoline. The Fe12 core of 1 is a type never previously encountered in FeIII carboxylate chemistry, consisting of two Fe6 units each of which comprises two {Fe3(μ3-O2-)} units bridged by three Me2AsO2- groups and linked into an Fe12 loop structure by two anti-anti η1:η1:μ Me2AsO2- groups, a bridging mode extremely rare with carboxylates. 2 also consists of two Fe6 units, differing in their ligation from those in 1, and this time linked together into a linear structure by a central {Na2(NO3)2} bridging unit. 3 is a linear Fe3 complex with no monatomic bridges between FeIII ions, a very rare situation in FeIII chemistry with any ligands and unprecedented in Fe carboxylate chemistry. The distinct differences observed in arsinate vs carboxylate ligation modes are rationalized largely based on the greater basicity of the former vs the latter. Variable-temperature dc and ac magnetic susceptibility data reveal all Fe2 pairwise interactions to be antiferromagnetic. For 1 and 2, the different Jij couplings were estimated by use of a magnetostructural correlation for high nuclearity FeIII-oxo clusters and by density functional theory calculations using broken symmetry methods, allowing identification of their relative spin vector alignments and thus rationalization of their S = 0 ground states. The Jij values were then used as input values to give excellent fits of the experimental χMT vs T data. For 3, the fits of the experimental χMT vs T data to the Van Vleck equation or with PHI gave a very weak J12 = -0.8(1) cm-1 (H = -2JŜi·Ŝj convention) between adjacent FeIII ions and an S = 5/2 ground state. These initial FeIII arsinate complexes also provide structural parameters that help validate literature assignments of arsinate binding modes to iron oxide/hydroxide minerals as part of environmental concerns of using arsenic-containing herbicides in agriculture.
Collapse
Affiliation(s)
- Kenneth Hong Kit Lee
- Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, United States
| | - Juan E Peralta
- Department of Physics and Science of Advanced Materials, Central Michigan University, Mount Pleasant, Michigan 48859, United States
| | - Khalil A Abboud
- Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, United States
| | - George Christou
- Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, United States
| |
Collapse
|
34
|
Henderson WR, Kumar A, Abboud KA, Castellano RK. Influence of Amide Connectivity on the Hydrogen‐Bond‐Directed Self‐Assembly of [n.n]Paracyclophanes. Chemistry 2020; 26:17588-17597. [DOI: 10.1002/chem.202003909] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 09/22/2020] [Indexed: 02/02/2023]
Affiliation(s)
- Will R. Henderson
- George & Josephine Butler Polymer Research Laboratory Center for Macromolecular Science & Engineering Department of Chemistry University of Florida, P.O. Box 117200 Gainesville Florida 32611 USA
| | - Ajeet Kumar
- George & Josephine Butler Polymer Research Laboratory Center for Macromolecular Science & Engineering Department of Chemistry University of Florida, P.O. Box 117200 Gainesville Florida 32611 USA
| | - Khalil A. Abboud
- George & Josephine Butler Polymer Research Laboratory Center for Macromolecular Science & Engineering Department of Chemistry University of Florida, P.O. Box 117200 Gainesville Florida 32611 USA
| | - Ronald K. Castellano
- George & Josephine Butler Polymer Research Laboratory Center for Macromolecular Science & Engineering Department of Chemistry University of Florida, P.O. Box 117200 Gainesville Florida 32611 USA
| |
Collapse
|
35
|
Abstract
Amines such as 1,2,3,4-tetrahydroisoquinoline undergo redox-neutral annulations with ortho-(nitromethyl)benzaldehyde. Benzoic acid acts as a promoter in these reactions, which involve concurrent amine α-C-H bond and N-H bond functionalization. Subsequent removal of the nitro group provides access to tetrahydroprotoberberines not accessible via typical redox-annulations. Also reported are decarboxylative annulations of ortho-(nitromethyl)benzaldehyde with proline and pipecolic acid.
Collapse
Affiliation(s)
- Dillon R L Rickertsen
- Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, Florida 32611, USA
| | - Longle Ma
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, USA
| | - Anirudra Paul
- Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, Florida 32611, USA
| | - Khalil A Abboud
- Center for X-ray Crystallography, Department of Chemistry, University of Florida, Gainesville, Florida 32611, USA
| | - Daniel Seidel
- Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, Florida 32611, USA
| |
Collapse
|
36
|
Semenova E, Lahtigui O, Scott SK, Albritton M, Abboud KA, Ghiviriga I, Roitberg AE, Grenning AJ. Selective ring-rearrangement or ring-closing metathesis of bicyclo[3.2.1]octenes. Chem Commun (Camb) 2020; 56:11779-11782. [PMID: 32940291 DOI: 10.1039/d0cc04624h] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Explored was the competitive ring-closing metathesis vs. ring-rearrangement metathesis of bicyclo[3.2.1]octenes prepared by a simple and convergent synthesis from bicyclic alkylidenemalono-nitriles and allylic electrophiles. It was uncovered that ring-closing metathesis occurs exclusively on the tetraene-variant, yielding unique, stereochemically and functionally rich polycyclic bridged frameworks, whereas the reduced version (a triene) undergoes ring-rearrangement metathesis to 5-6-5 fused ring systems resembling the isoryanodane core.
Collapse
Affiliation(s)
- Evgeniya Semenova
- Department of Chemistry, University of Florida, P. O. Box 117200, Gainesville, FL, USA.
| | | | | | | | | | | | | | | |
Collapse
|
37
|
Abstract
π-Conjugated oligomers functionalized with the popular dicyanorhodanine (RCN) electron acceptor are shown to be susceptible to photo-induced Z/E isomerization. The stereochemistry of two model RCN-functionalized thiophenes is confirmed by single crystal X-ray analysis and 2D NMR, and shown to be the thermodynamically stable Z form. Relative energies, Z/E configurations, and conformational preferences are modelled using density functional theory (DFT). The photophysical properties of the model compounds are explored experimentally and computationally; the Z and E isomers display similar absorption profiles with significant spectral overlap and are inseparable upon irradiation to a photostationary state. The well-behaved photoisomerization process is routinely observable by thin-layer chromatography, UV-vis, and NMR, and the photochemical behavior of the two RCN-functionalized thiophenes is characterized under varying wavelengths of irradiation. Ultraviolet (254 nm) irradiation results in photostationary state compositions of 56/44 and 69/31 Z-isomer/E-isomer for substrates functionalized with one thiophene and two thiophenes, respectively. Ambient laboratory lighting results in excess of 10 percent E-isomer for each species in solution, an important consideration for processing such materials, particularly for organic photovoltaic applications. In addition, a photoswitching experiment is conducted to demonstrate the reversible nature of the photoreaction, where little evidence of fatigue is observed over numerous switching cycles. Overall, this work showcases an approach to characterize the stereochemistry and photochemical behavior of dicyanorhodanine-functionalized thiophenes, widely used components of functional molecules and materials.
Collapse
Affiliation(s)
- Cory T Kornman
- Department of Chemistry, University of Florida PO Box 117200 Gainesville FL 32611 USA
| | - Lei Li
- Department of Chemistry, University of Florida PO Box 117200 Gainesville FL 32611 USA .,Department of Materials Science and Engineering, Center for Optical Materials Science and Engineering Technologies (COMSET), Clemson University Clemson SC 29634 USA
| | - Asmerom O Weldeab
- Department of Chemistry, University of Florida PO Box 117200 Gainesville FL 32611 USA
| | - Ion Ghiviriga
- Department of Chemistry, University of Florida PO Box 117200 Gainesville FL 32611 USA
| | - Khalil A Abboud
- Department of Chemistry, University of Florida PO Box 117200 Gainesville FL 32611 USA
| | - Ronald K Castellano
- Department of Chemistry, University of Florida PO Box 117200 Gainesville FL 32611 USA
| |
Collapse
|
38
|
Zhu Z, Odagi M, Supantanapong N, Xu W, Saame J, Kirm HU, Abboud KA, Leito I, Seidel D. Modular Design of Chiral Conjugate-Base-Stabilized Carboxylic Acids: Catalytic Enantioselective [4 + 2] Cycloadditions of Acetals. J Am Chem Soc 2020; 142:15252-15258. [PMID: 32830974 DOI: 10.1021/jacs.0c07212] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Readily available 1,2-amino alcohols provide the framework for a new generation of chiral carboxylic acid catalysts that rival the acidity of the widely used chiral phosphoric acid catalyst (S)-TRIP. Covalently linked thiourea sites stabilize the carboxylate conjugate bases of these catalysts via anion-binding, an interaction that is largely responsible for the low pKa values. The utility of the new catalysts is illustrated in the context of challenging [4 + 2] cycloadditions of salicylaldehyde-derived acetals with homoallylic and bishomoallylic alcohols, providing polycyclic chromanes in a highly enantioselective fashion.
Collapse
Affiliation(s)
- Zhengbo Zhu
- Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| | - Minami Odagi
- Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States.,Department of Biotechnology and Life Science, Graduate School of Technology, Tokyo University of Agriculture and Technology, 2-24-16, Naka-cho, Koganei city, 184-8588, Tokyo, Japan
| | - Nantamon Supantanapong
- Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| | - Weici Xu
- Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| | - Jaan Saame
- Institute of Chemistry, University of Tartu, Tartu, Estonia
| | | | - Khalil A Abboud
- Center for X-ray Crystallography, Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| | - Ivo Leito
- Institute of Chemistry, University of Tartu, Tartu, Estonia
| | - Daniel Seidel
- Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| |
Collapse
|
39
|
Scheutz GM, Rowell JL, Wang FS, Abboud KA, Peng CH, Sumerlin BS. Synthesis of functional 1,2-dithiolanes from 1,3-bis- tert-butyl thioethers. Org Biomol Chem 2020; 18:6509-6513. [PMID: 32797130 DOI: 10.1039/d0ob01577f] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
We report the one-step synthesis of diversely substituted functional 1,2-dithiolanes by reacting readily accessible 1,3-bis-tert-butyl thioethers with bromine. The reaction proceeds to completion within minutes under mild conditions, presumably via a sulfonium-mediated ring closure. Using X-ray crystallography and UV-vis spectroscopy, we demonstrate how substituent size and ring substitution pattern can affect the geometry and photophysical properties of 1,2-dithiolanes.
Collapse
Affiliation(s)
- Georg M Scheutz
- George & Josephine Butler Polymer Research Laboratory, Center for Macromolecular Science & Engineering, Department of Chemistry, University of Florida, Gainesville, FL 32611, USA.
| | - Jonathan L Rowell
- George & Josephine Butler Polymer Research Laboratory, Center for Macromolecular Science & Engineering, Department of Chemistry, University of Florida, Gainesville, FL 32611, USA.
| | - Fu-Sheng Wang
- Department of Chemistry and Frontier Research Center on Fundamental and Applied Sciences of Matters, National Tsing Hua University, 101, Sec 2, Kuang-Fu Rd., Hsinchu 30013, Taiwan
| | - Khalil A Abboud
- George & Josephine Butler Polymer Research Laboratory, Center for Macromolecular Science & Engineering, Department of Chemistry, University of Florida, Gainesville, FL 32611, USA.
| | - Chi-How Peng
- Department of Chemistry and Frontier Research Center on Fundamental and Applied Sciences of Matters, National Tsing Hua University, 101, Sec 2, Kuang-Fu Rd., Hsinchu 30013, Taiwan
| | - Brent S Sumerlin
- George & Josephine Butler Polymer Research Laboratory, Center for Macromolecular Science & Engineering, Department of Chemistry, University of Florida, Gainesville, FL 32611, USA.
| |
Collapse
|
40
|
Zeman CJ, Shen YH, Heller JK, Abboud KA, Schanze KS, Veige AS. Correction to "Excited-State Turn-On of Aurophilicity and Tunability of Relativistic Effects in a Series of Digold Triazolates Synthesized via iClick". J Am Chem Soc 2020; 142:14391. [PMID: 32787266 DOI: 10.1021/jacs.0c07691] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
41
|
Papke RL, Garai S, Stokes C, Horenstein NA, Zimmerman AD, Abboud KA, Thakur GA. Differing Activity Profiles of the Stereoisomers of 2,3,5,6TMP-TQS, a Putative Silent Allosteric Modulator of α7 nAChR. Mol Pharmacol 2020; 98:292-302. [PMID: 32690627 DOI: 10.1124/mol.120.119958] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Accepted: 07/13/2020] [Indexed: 12/20/2022] Open
Abstract
Many synthetic compounds to which we attribute specific activities are produced as racemic mixtures of stereoisomers, and it may be that all the desired activity comes from a single enantiomer. We have previously shown this to be the case with the α7 nicotinic acetylcholine receptor positive allosteric modulator (PAM) 3a,4,5,9b-Tetrahydro-4-(1-naphthalenyl)-3H-cyclopentan[c]quinoline-8-sulfonamide (TQS) and the α7 ago-PAM 4BP-TQS. Cis-trans-4-(2,3,5,6-tetramethylphenyl)-3a,4,5,9b-te-trahydro-3H-cyclopenta[c]quinoline-8-sulfonamide (2,3,5,6TMP-TQS), previously published as a "silent allosteric modulator" and an antagonist of α7 allosteric activation, shares the same scaffold with three chiral centers as the aforementioned compounds. We isolated the enantiomers of 2,3,5,6TMP-TQS and determined that the (-) isomer was a significantly better antagonist than the (+) isomer of the allosteric activation of both wild-type α7 and the nonorthosterically activatible C190A α7 mutant by the ago-PAM GAT107 (the active isomer of 4BP-TQS). In contrast, (+)2,3,5,6TMP-TQS proved to be an α7 PAM. (-)2,3,5,6TMP-TQS was shown to antagonize the allosteric activation of α7 by the structurally unrelated ago-PAM B-973B as well as the allosteric activation of the TQS-sensitive α4β2L15'M mutant. In silico docking of 2,3,5,6TMP-TQS in the putative allosteric activation binding site suggested a specific interaction of the (-) enantiomer with α7T106, and allosteric activation of α7T106 mutants was not inhibited by (-)2,3,5,6TMP-TQS, confirming the importance of this interaction and supporting the model of the allosteric binding site. Comparisons and contrasts between 2,3,5,6TMP-TQS isomers and active and inactive enantiomers of other TQS-related compounds identify the orientation of the cyclopentenyl ring to the plane of the core quinoline to be a crucial determinate of PAM activity. SIGNIFICANCE STATEMENT: Many synthetic ligands are in use as racemic preparations. We show that one enantiomer of the TQS analog Cis-trans-4-(2,3,5,6-tetramethylphenyl)-3a,4,5,9b-te-trahydro-3H-cyclopenta[c]quinoline-8-sulfonamide, originally reported to lack activity when used as a racemic preparation, is an α7 nicotinic acetylcholine receptor positive allosteric modulator (PAM). The other enantiomer is not a PAM, but it is an effective allosteric antagonist. In silico studies and structural comparisons identify essential elements of both the allosteric ligands and receptor binding sites important for these allosteric activities.
Collapse
Affiliation(s)
- Roger L Papke
- Departments of Pharmacology and Therapeutics (R.L.P., C.S., A.D.Z.) and Chemistry (N.A.H., K.A.A.), University of Florida, Gainesville, Florida; and Department of Pharmaceutical Sciences, School of Pharmacy, Bouvé College of Health Sciences, Northeastern University, Boston, Massachusetts (S.G., G.A.T.)
| | - Sumanta Garai
- Departments of Pharmacology and Therapeutics (R.L.P., C.S., A.D.Z.) and Chemistry (N.A.H., K.A.A.), University of Florida, Gainesville, Florida; and Department of Pharmaceutical Sciences, School of Pharmacy, Bouvé College of Health Sciences, Northeastern University, Boston, Massachusetts (S.G., G.A.T.)
| | - Clare Stokes
- Departments of Pharmacology and Therapeutics (R.L.P., C.S., A.D.Z.) and Chemistry (N.A.H., K.A.A.), University of Florida, Gainesville, Florida; and Department of Pharmaceutical Sciences, School of Pharmacy, Bouvé College of Health Sciences, Northeastern University, Boston, Massachusetts (S.G., G.A.T.)
| | - Nicole A Horenstein
- Departments of Pharmacology and Therapeutics (R.L.P., C.S., A.D.Z.) and Chemistry (N.A.H., K.A.A.), University of Florida, Gainesville, Florida; and Department of Pharmaceutical Sciences, School of Pharmacy, Bouvé College of Health Sciences, Northeastern University, Boston, Massachusetts (S.G., G.A.T.)
| | - Arthur D Zimmerman
- Departments of Pharmacology and Therapeutics (R.L.P., C.S., A.D.Z.) and Chemistry (N.A.H., K.A.A.), University of Florida, Gainesville, Florida; and Department of Pharmaceutical Sciences, School of Pharmacy, Bouvé College of Health Sciences, Northeastern University, Boston, Massachusetts (S.G., G.A.T.)
| | - Khalil A Abboud
- Departments of Pharmacology and Therapeutics (R.L.P., C.S., A.D.Z.) and Chemistry (N.A.H., K.A.A.), University of Florida, Gainesville, Florida; and Department of Pharmaceutical Sciences, School of Pharmacy, Bouvé College of Health Sciences, Northeastern University, Boston, Massachusetts (S.G., G.A.T.)
| | - Ganesh A Thakur
- Departments of Pharmacology and Therapeutics (R.L.P., C.S., A.D.Z.) and Chemistry (N.A.H., K.A.A.), University of Florida, Gainesville, Florida; and Department of Pharmaceutical Sciences, School of Pharmacy, Bouvé College of Health Sciences, Northeastern University, Boston, Massachusetts (S.G., G.A.T.)
| |
Collapse
|
42
|
Das Gupta S, Stewart RL, Chen DT, Abboud KA, Cheng HP, Hill S, Christou G. Long-Range Ferromagnetic Exchange Interactions Mediated by Mn-Ce IV-Mn Superexchange Involving Empty 4f Orbitals. Inorg Chem 2020; 59:8716-8726. [PMID: 32573216 DOI: 10.1021/acs.inorgchem.0c00332] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Reactions involving reductive aggregation of MnO4- in methanol in the presence of CeIV and an excess of carboxylic acid have led to the synthesis of structurally related Ce/Mn clusters, [Ce3Mn5O8(OMe)(O2CBut)13(MeOH)] (1) and [Ce2Mn3O5(O2CPh)9(MeOH)3] (2), containing at least one {Mn2Ce2O4} cubane unit. The cores of both clusters contain Mnx units separated by three (1) or two (2) CeIV ions. Fits of variable-temperature, solid-state dc and ac magnetic susceptibility data reveal dominant ferromagnetic interactions within 1 and 2, resulting in the maximum S = 17/2 and S = 5 ground state spins, respectively, and thus suggesting significant ferromagnetic (F) interactions between the Mnx units that are ≥6 Å apart and separated by four intervening bonds through diamagnetic CeIV. Fits of magnetic susceptibility data also revealed unusual long-range F interactions, and this finding was further supported by high-field EPR measurements and simulations. Density functional theory calculations and a Wannier function analysis confirm long-range interactions and indicate a Mn-Ce-Mn superexchange pathway via Mn-d/Ce-f orbital overlap/hybridization.
Collapse
Affiliation(s)
- Sayak Das Gupta
- Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| | - Robert L Stewart
- National High Magnetic Field Laboratory and Department of Physics, Florida State University, Tallahassee, Florida 32310, United States
| | - Dian-Teng Chen
- Department of Physics, University of Florida, Gainesville, Florida 32611, United States
| | - Khalil A Abboud
- Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| | - Hai-Ping Cheng
- Department of Physics, University of Florida, Gainesville, Florida 32611, United States
| | - Stephen Hill
- National High Magnetic Field Laboratory and Department of Physics, Florida State University, Tallahassee, Florida 32310, United States
| | - George Christou
- Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| |
Collapse
|
43
|
Mandal U, VenkatRamani S, Ghiviriga I, Abboud KA, Veige AS. Synthesis and Characterization of Tungsten Alkylidene and Alkylidyne Complexes Featuring a New Carbazole-Based Rigid Trianionic ONO 3– Pincer-Type Ligand. Organometallics 2020. [DOI: 10.1021/acs.organomet.0c00150] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ushnish Mandal
- University of Florida, Department of Chemistry, Center for Catalysis, P.O. Box 117200, Gainesville, Florida 32611, United States
| | - Sudarsan VenkatRamani
- University of Florida, Department of Chemistry, Center for Catalysis, P.O. Box 117200, Gainesville, Florida 32611, United States
| | - Ion Ghiviriga
- University of Florida, Department of Chemistry, Center for Catalysis, P.O. Box 117200, Gainesville, Florida 32611, United States
| | - Khalil A. Abboud
- University of Florida, Department of Chemistry, Center for Catalysis, P.O. Box 117200, Gainesville, Florida 32611, United States
| | - Adam S. Veige
- University of Florida, Department of Chemistry, Center for Catalysis, P.O. Box 117200, Gainesville, Florida 32611, United States
| |
Collapse
|
44
|
Norwood V, Brice-Tutt AC, Eans SO, Stacy HM, Shi G, Ratnayake R, Rocca JR, Abboud KA, Li C, Luesch H, McLaughlin JP, Huigens RW. Preventing Morphine-Seeking Behavior through the Re-Engineering of Vincamine's Biological Activity. J Med Chem 2020; 63:5119-5138. [PMID: 31913038 PMCID: PMC7324933 DOI: 10.1021/acs.jmedchem.9b01924] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Indexed: 12/17/2022]
Abstract
Innovative discovery strategies are essential to address the ongoing opioid epidemic in the United States. Misuse of prescription and illegal opioids (e.g., morphine, heroin) has led to major problems with addiction and overdose. We used vincamine, an indole alkaloid, as a synthetic starting point for dramatic structural alterations of its complex, fused ring system to synthesize 80 diverse compounds with intricate molecular architectures. A select series of vincamine-derived compounds were screened for both agonistic and antagonistic activities against a panel of 168 G protein-coupled receptor (GPCR) drug targets. Although vincamine was without an effect, the novel compound 4 (V2a) demonstrated antagonistic activities against hypocretin (orexin) receptor 2. When advanced to animal studies, 4 (V2a) significantly prevented acute morphine-conditioned place preference (CPP) and stress-induced reinstatement of extinguished morphine-CPP in mouse models of opioid reward and relapse. These results demonstrate that the ring distortion of vincamine offers a promising way to explore new chemical space of relevance to opioid addiction.
Collapse
Affiliation(s)
- Verrill
M. Norwood
- Department
of Medicinal Chemistry, College of Pharmacy, University of Florida, Gainesville, Florida 32610, United States
- Center
for Natural Products, Drug Discovery & Development (CNPD3), College
of Pharmacy, University of Florida, Gainesville, Florida 32610, United States
| | - Ariana C. Brice-Tutt
- Department
of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, Florida 32610, United States
- Center
for Natural Products, Drug Discovery & Development (CNPD3), College
of Pharmacy, University of Florida, Gainesville, Florida 32610, United States
| | - Shainnel O. Eans
- Department
of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, Florida 32610, United States
- Center
for Natural Products, Drug Discovery & Development (CNPD3), College
of Pharmacy, University of Florida, Gainesville, Florida 32610, United States
| | - Heather M. Stacy
- Department
of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, Florida 32610, United States
- Center
for Natural Products, Drug Discovery & Development (CNPD3), College
of Pharmacy, University of Florida, Gainesville, Florida 32610, United States
| | - Guqin Shi
- Department
of Medicinal Chemistry, College of Pharmacy, University of Florida, Gainesville, Florida 32610, United States
- Center
for Natural Products, Drug Discovery & Development (CNPD3), College
of Pharmacy, University of Florida, Gainesville, Florida 32610, United States
| | - Ranjala Ratnayake
- Department
of Medicinal Chemistry, College of Pharmacy, University of Florida, Gainesville, Florida 32610, United States
- Center
for Natural Products, Drug Discovery & Development (CNPD3), College
of Pharmacy, University of Florida, Gainesville, Florida 32610, United States
| | - James R. Rocca
- Department
of Medicinal Chemistry, College of Pharmacy, University of Florida, Gainesville, Florida 32610, United States
- McKnight
Brain Institute, University of Florida, Gainesville, Florida 32610, United States
| | - Khalil A. Abboud
- Department
of Chemistry, University of Florida, Gainesville, Florida 32610, United States
| | - Chenglong Li
- Department
of Medicinal Chemistry, College of Pharmacy, University of Florida, Gainesville, Florida 32610, United States
- Center
for Natural Products, Drug Discovery & Development (CNPD3), College
of Pharmacy, University of Florida, Gainesville, Florida 32610, United States
| | - Hendrik Luesch
- Department
of Medicinal Chemistry, College of Pharmacy, University of Florida, Gainesville, Florida 32610, United States
- Center
for Natural Products, Drug Discovery & Development (CNPD3), College
of Pharmacy, University of Florida, Gainesville, Florida 32610, United States
| | - Jay P. McLaughlin
- Department
of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, Florida 32610, United States
- Center
for Natural Products, Drug Discovery & Development (CNPD3), College
of Pharmacy, University of Florida, Gainesville, Florida 32610, United States
| | - Robert W. Huigens
- Department
of Medicinal Chemistry, College of Pharmacy, University of Florida, Gainesville, Florida 32610, United States
- Center
for Natural Products, Drug Discovery & Development (CNPD3), College
of Pharmacy, University of Florida, Gainesville, Florida 32610, United States
| |
Collapse
|
45
|
Russell-Webster B, Abboud KA, Christou G. Molecular nanoparticles of cerium dioxide: structure-directing effect of halide ions. Chem Commun (Camb) 2020; 56:5382-5385. [PMID: 32285863 DOI: 10.1039/c9cc08419c] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The use of halide ions in the synthesis of Ce/O clusters diverts the reaction to two halide-containing products: Cl- gives a new Ce20 nuclearity with both a high 1 : 1 Ce3+ : Ce4+ ratio and a high percentage of (100) facet coverage, whereas F- gives a known Ce6 nuclearity. Both products include bridging halide ions and are thus the first confirmation of non-oxo (OH-/O2-) anion incorporation onto the Ce/O cluster core.
Collapse
Affiliation(s)
| | - Khalil A Abboud
- Department of Chemistry, University of Florida, Gainesville, FL 32611-7200, USA.
| | - George Christou
- Department of Chemistry, University of Florida, Gainesville, FL 32611-7200, USA.
| |
Collapse
|
46
|
Zeman CJ, Shen YH, Heller JK, Abboud KA, Schanze KS, Veige AS. Excited-State Turn-On of Aurophilicity and Tunability of Relativistic Effects in a Series of Digold Triazolates Synthesized via iClick. J Am Chem Soc 2020; 142:8331-8341. [PMID: 32267156 DOI: 10.1021/jacs.0c01624] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
iClick reactions between Au(I) acetylides PPh3Au-C≡CR, where R = nitrophenyl (PhNO2), phenyl (Ph), thiophene (Th), bithiophene (biTh), and dimethyl aniline (PhNMe2), and Au(I)-azide PPh3AuN3 provide digold complexes of the general formula R-1,5-bis-triphenylphosphinegold(I) 1,2,3-triazolate (Au2-R). Within the digold triazolate complexes the Au(I) atoms are held in close proximity but beyond the distance typically observed for aurophilic bonding. Though no bond exists in the ground state, time-dependent density functional theory interrogation of the complexes reveals excited states with significant aurophilic bonding. The series of complexes allows for tuning of the excited-state "turn-on" of aurophilicity, where ligand to metal charge transfer (LMCT) induces the aurophilic bonding. Complexes containing ligand-localized excited states, however, do not exhibit aurophilicity in the excited state. As a control experiment, a monogold complex was synthesized. The computed excited state of the monogold species exhibited LMCT to the gold ion as in the dinuclear cases, but without a partnering gold ion only a distinct N-Au-P bending occurs, revealing a potential mechanism for the excited-state turn-on of aurophilic bonding. Analysis of the steady-state electronic spectra indicates that LMCT states are achievable for compounds with sufficiently strong electron-donating ligands, and in digold complexes this is associated with enhanced fluorescence, suggestive of an aurophilic interaction.
Collapse
Affiliation(s)
- Charles J Zeman
- Department of Chemistry, Center for Catalysis, University of Florida, P.O. Box 117200, Gainesville, Florida 32611, United States.,Department of Chemistry, University of Texas at San Antonio, One UTSA Circle, San Antonio, Texas 78249, United States
| | - Yu-Hsuan Shen
- Department of Chemistry, Center for Catalysis, University of Florida, P.O. Box 117200, Gainesville, Florida 32611, United States
| | - Jessica K Heller
- Department of Chemistry, Center for Catalysis, University of Florida, P.O. Box 117200, Gainesville, Florida 32611, United States
| | - Khalil A Abboud
- Department of Chemistry, Center for Catalysis, University of Florida, P.O. Box 117200, Gainesville, Florida 32611, United States
| | - Kirk S Schanze
- Department of Chemistry, University of Texas at San Antonio, One UTSA Circle, San Antonio, Texas 78249, United States
| | - Adam S Veige
- Department of Chemistry, Center for Catalysis, University of Florida, P.O. Box 117200, Gainesville, Florida 32611, United States
| |
Collapse
|
47
|
Lin Y, Hirschi WJ, Kunadia A, Paul A, Ghiviriga I, Abboud KA, Karugu RW, Vetticatt MJ, Hirschi JS, Seidel D. A Selenourea-Thiourea Brønsted Acid Catalyst Facilitates Asymmetric Conjugate Additions of Amines to α,β-Unsaturated Esters. J Am Chem Soc 2020; 142:5627-5635. [PMID: 32118419 DOI: 10.1021/jacs.9b12457] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
β-Amino esters are obtained with high levels of enantioselectivity via the conjugate addition of cyclic amines to unactivated α,β-unsaturated esters. A related strategy enables the kinetic resolution of racemic cyclic 2-arylamines, using benzyl acrylate as the resolving agent. Reactions are facilitated by an unprecedented selenourea-thiourea organocatalyst. As elucidated by DFT calculations and 13C kinetic isotope effect studies, the rate-limiting and enantiodetermining step of the reaction is the protonation of a zwitterionic intermediate by the catalyst. This represents a rare case in which a thiourea compound functions as an asymmetric Brønsted acid catalyst.
Collapse
Affiliation(s)
- Yingfu Lin
- Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States.,Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, United States
| | - William J Hirschi
- Department of Chemistry, Binghamton University, Binghamton, New York 13902, United States
| | - Anuj Kunadia
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, United States
| | - Anirudra Paul
- Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States.,Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, United States
| | - Ion Ghiviriga
- Center for NMR Spectroscopy, Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| | - Khalil A Abboud
- Center for X-ray Crystallography, Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| | - Rachael W Karugu
- Department of Chemistry, Binghamton University, Binghamton, New York 13902, United States
| | - Mathew J Vetticatt
- Department of Chemistry, Binghamton University, Binghamton, New York 13902, United States
| | - Jennifer S Hirschi
- Department of Chemistry, Binghamton University, Binghamton, New York 13902, United States
| | - Daniel Seidel
- Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States.,Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, United States
| |
Collapse
|
48
|
Cao TS, Chen DT, Abboud KA, Zhang X, Cheng HP, Christou G. Feasibility of ground state spin switching in a molecular analogue of the mixed-metal oxides with the perovskite structure. Polyhedron 2020. [DOI: 10.1016/j.poly.2019.114275] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
49
|
Singh AP, Joshi RP, Abboud KA, Peralta JE, Christou G. Molecular spin frustration in mixed-chelate Fe5 and Fe6 oxo clusters with high ground state spin values. Polyhedron 2020. [DOI: 10.1016/j.poly.2019.114182] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
50
|
Henderson WR, Zhu Y, Fagnani DE, Liu G, Abboud KA, Castellano RK. Self-Assembling [n.n]Paracyclophanes: A Structure–Property Relationship Study. J Org Chem 2019; 85:1158-1167. [DOI: 10.1021/acs.joc.9b03120] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Will R. Henderson
- Department of Chemistry, University of Florida, PO Box 117200, Gainesville, Florida 32611-7200, United States
| | - Yu Zhu
- Department of Chemistry, University of Florida, PO Box 117200, Gainesville, Florida 32611-7200, United States
| | - Danielle E. Fagnani
- Department of Chemistry, University of Florida, PO Box 117200, Gainesville, Florida 32611-7200, United States
| | - Guancen Liu
- Department of Chemistry, University of Florida, PO Box 117200, Gainesville, Florida 32611-7200, United States
| | - Khalil A. Abboud
- Department of Chemistry, University of Florida, PO Box 117200, Gainesville, Florida 32611-7200, United States
| | - Ronald K. Castellano
- Department of Chemistry, University of Florida, PO Box 117200, Gainesville, Florida 32611-7200, United States
| |
Collapse
|