1
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Pikma ML, Tshepelevitsh S, Selberg S, Kaljurand I, Leito I, Kütt A. p KaH values and θH angles of phosphanes to predict their electronic and steric parameters. Dalton Trans 2024. [PMID: 39129417 DOI: 10.1039/d4dt01430h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/13/2024]
Abstract
Phosphanes play an important role in various applications, serving as a class of organic bases with basicities spanning more than 30 orders of magnitude. Accessing comprehensive basicity data for phosphanes has been challenging due to scattered information across multiple sources and notable gaps in the existing data. In this report, we present basicities (pKaH values) of a diverse set of phosphanes, both newly measured or calculated and collected from the literature. We demonstrate that pKaH values can serve as an alternative to Tolman electronic parameters (TEP values) in evaluating the electronic properties of phosphanes. Additionally, we suggest parameters for assessing the steric properties of phosphanes without the need for preparation or calculation of metal-ligand complexes.
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Affiliation(s)
- Marta-Lisette Pikma
- Institute of Chemistry, University of Tartu, Ravila 14a, Tartu 50411, Estonia.
| | - Sofja Tshepelevitsh
- Institute of Chemistry, University of Tartu, Ravila 14a, Tartu 50411, Estonia.
| | - Sigrid Selberg
- Institute of Chemistry, University of Tartu, Ravila 14a, Tartu 50411, Estonia.
| | - Ivari Kaljurand
- Institute of Chemistry, University of Tartu, Ravila 14a, Tartu 50411, Estonia.
| | - Ivo Leito
- Institute of Chemistry, University of Tartu, Ravila 14a, Tartu 50411, Estonia.
| | - Agnes Kütt
- Institute of Chemistry, University of Tartu, Ravila 14a, Tartu 50411, Estonia.
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2
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Kikkawa S, Fujiki Y, Chudatemiya V, Nagakari H, Shibusawa K, Hirayama J, Nakatani N, Yamazoe S. Water-Tolerant Superbase Polyoxometalate [H 2(Nb 6O 19)] 6- for Homogeneous Catalysis. Angew Chem Int Ed Engl 2024; 63:e202401526. [PMID: 38388816 DOI: 10.1002/anie.202401526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Revised: 02/20/2024] [Accepted: 02/21/2024] [Indexed: 02/24/2024]
Abstract
Here, doubly protonated Lindqvist-type niobium oxide cluster [H2(Nb6O19)]6-, fabricated by microwave-assisted hydrothermal synthesis, exhibited superbase catalysis for Knoevenagel and crossed aldol condensation reactions accompanied by activating C-H bond with pKa >26 and proton abstraction from a base indicator with pKa=26.5. Surprisingly, [H2(Nb6O19)]6- exhibited water-tolerant superbase properties for Knoevenagel and crossed aldol condensation reactions in the presence of water, although it is well known that the strong basicity of metal oxides and organic superbase is typically lost by the adsorption of water. Density functional theory calculation revealed that the basic surface oxygens that share the corner of NbO6 units in [H2(Nb6O19)]8- maintained the negative charges even after proton adsorption. This proton capacity and the presence of un-protonated basic sites led to the water tolerance of the superbase catalysis.
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Affiliation(s)
- Soichi Kikkawa
- Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo, 192-0397, Japan
- Elements Strategy Initiative for Catalysts & Batteries (ESICB), Kyoto University, 1-30, Goryo-Ohara, Nishikyo-ku, Kyoto, 615-8245, Japan
| | - Yu Fujiki
- Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo, 192-0397, Japan
| | - Vorakit Chudatemiya
- Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo, 192-0397, Japan
| | - Hiroki Nagakari
- Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo, 192-0397, Japan
| | - Kazuki Shibusawa
- Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo, 192-0397, Japan
| | - Jun Hirayama
- Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo, 192-0397, Japan
- Elements Strategy Initiative for Catalysts & Batteries (ESICB), Kyoto University, 1-30, Goryo-Ohara, Nishikyo-ku, Kyoto, 615-8245, Japan
| | - Naoki Nakatani
- Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo, 192-0397, Japan
| | - Seiji Yamazoe
- Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo, 192-0397, Japan
- Elements Strategy Initiative for Catalysts & Batteries (ESICB), Kyoto University, 1-30, Goryo-Ohara, Nishikyo-ku, Kyoto, 615-8245, Japan
- Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency (JST) 4-1-8, Honcho, Kawaguchi, Saitama, 332-0012, Japan
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3
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Saha A, Ganguly B. Exploiting the (-C-H···C-) Interaction to Design Cage-Functionalized Organic Superbases and Hyperbases: A Computational Study. ACS OMEGA 2023; 8:38546-38556. [PMID: 37867725 PMCID: PMC10586256 DOI: 10.1021/acsomega.3c05401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Accepted: 09/22/2023] [Indexed: 10/24/2023]
Abstract
A set of carbon center-based P-ylidesubstituting bases have been exploited computationally with pentacyclo[5.4.0.02,6.03,10.05.9]undecane (PCU) and pentacyclo [6.4.0.02,7.03,11.06,10] dodecane (PCD) scaffolds using the B3LYP-D3/6-311+G(d,p) level of theory. The proton affinities calculated in the gas phase are in the range of superbases and hyperbases. The Atomsin-Molecules and Natural Bond Orbital calculations reveal that the -C-H···C- interaction plays a substantial role in improving the basicity, and tuning the -C-H···C- interaction can enhance the basicity of such systems. The free activation energy for proton exchange for PCD and PCU scaffolds substituted with P-ylide is substantially low. The computed results reveal the strength and nature of such - C-H···C- interactions compared to the -N-H···N- hydrogen bonds. The isodesmic reactions suggest that the superbasicity achieved using these frameworks arises from a combination of several factors, such as the ring strain of the bases in their unprotonated form, steric repulsion, and the intramolecular -C-H···C- interaction.
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Affiliation(s)
- Anusuya Saha
- Computation
and Simulation Unit, Analytical and Environmental Science Division
and Centralized Instrument Facility, CSIR-Central
Salt & Marine Chemicals Research Institute, Bhavnagar, Gujarat 364002, India
- Academy
of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Bishwajit Ganguly
- Computation
and Simulation Unit, Analytical and Environmental Science Division
and Centralized Instrument Facility, CSIR-Central
Salt & Marine Chemicals Research Institute, Bhavnagar, Gujarat 364002, India
- Academy
of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
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4
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Racochote S, Naweephattana P, Surawatanawong P, Kuhakarn C, Leowanawat P, Reutrakul V, Soorukram D. Base-catalyzed diastereodivergent thia-Michael addition to chiral β-trifluoromethyl-α,β-unsaturated N-acylated oxazolidin-2-ones. Org Biomol Chem 2023; 21:7180-7187. [PMID: 37624045 DOI: 10.1039/d3ob00999h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/26/2023]
Abstract
Base-catalyzed diastereodivergent thia-Michael addition of thiols to chiral β-trifluoromethyl-α,β-unsaturated N-acylated oxazolidin-2-ones is reported. By tuning the base-catalyst (i-Pr2NEt, DABCO, or P2-t-Bu), a range of chiral thia-Michael adducts was synthesized in good yields with high diastereoselectivities. A plausible mechanism was proposed on the basis of the experimental results. This work is complementary to the existing methods offering advantages, e.g., switchable diastereoselectivity using a readily synthesized chiral starting material, a cheap and readily available base catalyst, and a simple and practical operation, enabling synthetic application in organic synthesis.
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Affiliation(s)
- Sasirome Racochote
- Department of Chemistry and Center of Excellence for Innovation in Chemistry (PERCH-CIC), Faculty of Science, Mahidol University, Rama VI Road, Bangkok 10400, Thailand.
| | - Phiphob Naweephattana
- Department of Chemistry and Center of Excellence for Innovation in Chemistry (PERCH-CIC), Faculty of Science, Mahidol University, Rama VI Road, Bangkok 10400, Thailand.
| | - Panida Surawatanawong
- Department of Chemistry and Center of Excellence for Innovation in Chemistry (PERCH-CIC), Faculty of Science, Mahidol University, Rama VI Road, Bangkok 10400, Thailand.
| | - Chutima Kuhakarn
- Department of Chemistry and Center of Excellence for Innovation in Chemistry (PERCH-CIC), Faculty of Science, Mahidol University, Rama VI Road, Bangkok 10400, Thailand.
| | - Pawaret Leowanawat
- Department of Chemistry and Center of Excellence for Innovation in Chemistry (PERCH-CIC), Faculty of Science, Mahidol University, Rama VI Road, Bangkok 10400, Thailand.
| | - Vichai Reutrakul
- Department of Chemistry and Center of Excellence for Innovation in Chemistry (PERCH-CIC), Faculty of Science, Mahidol University, Rama VI Road, Bangkok 10400, Thailand.
| | - Darunee Soorukram
- Department of Chemistry and Center of Excellence for Innovation in Chemistry (PERCH-CIC), Faculty of Science, Mahidol University, Rama VI Road, Bangkok 10400, Thailand.
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5
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Radtke V, Priester D, Heering A, Müller C, Koslowski T, Leito I, Krossing I. The Unified Redox Scale for All Solvents: Consistency and Gibbs Transfer Energies of Electrolytes from their Constituent Single Ions. Chemistry 2023; 29:e202300609. [PMID: 37191477 DOI: 10.1002/chem.202300609] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 04/28/2023] [Accepted: 05/11/2023] [Indexed: 05/17/2023]
Abstract
We have devised the unified redox scale Eabs H2O , which is valid for all solvents. The necessary single ion Gibbs transfer energy between two different solvents, which only can be determined with extra-thermodynamic assumptions so far, must clearly satisfy two essential conditions: First, the sum of the independent cation and anion values must give the Gibbs transfer energy of the salt they form. The latter is an observable and measurable without extra-thermodynamic assumptions. Second, the values must be consistent for different solvent combinations. With this work, potentiometric measurements on silver ions and on chloride ions show that both conditions are fulfilled using a salt bridge filled with the ionic liquid [N2225 ][NTf2 ]: if compared to the values resulting from known pKL values, the silver and chloride single ion magnitudes combine within a uncertainty of 1.5 kJ mol-1 to the directly measurable transfer magnitudes of the salt AgCl from water to the solvents acetonitrile, propylene carbonate, dimethylformamide, ethanol, and methanol. The resulting values are used to further develop the consistent unified redox potential scale Eabs H2O that now allows to assess and compare redox potentials in and over six different solvents. We elaborate on its implications.
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Affiliation(s)
- Valentin Radtke
- Institut für Anorganische und, Analytische Chemie and Freiburger Materialforschungszentrum (FMF), Universität Freiburg, Albertstr. 21, 79104, Freiburg, Germany
| | - Denis Priester
- Institut für Anorganische und, Analytische Chemie and Freiburger Materialforschungszentrum (FMF), Universität Freiburg, Albertstr. 21, 79104, Freiburg, Germany
| | - Agnes Heering
- Institute of Chemistry, University of Tartu, Ravila 14a Str, 50411, Tartu, Estonia
| | - Carina Müller
- Institut für Anorganische und, Analytische Chemie and Freiburger Materialforschungszentrum (FMF), Universität Freiburg, Albertstr. 21, 79104, Freiburg, Germany
| | - Thorsten Koslowski
- Institut für Physikalische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstr. 21, 79104, Freiburg, Germany
| | - Ivo Leito
- Institute of Chemistry, University of Tartu, Ravila 14a Str, 50411, Tartu, Estonia
| | - Ingo Krossing
- Institut für Anorganische und, Analytische Chemie and Freiburger Materialforschungszentrum (FMF), Universität Freiburg, Albertstr. 21, 79104, Freiburg, Germany
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6
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Zhu M, Yu W, Zhong Q, Cui B, Cao C, Shi Y. Nickel-catalyzed Suzuki cross-coupling reaction of alkyl triaryl phosphonium salts. Tetrahedron 2023. [DOI: 10.1016/j.tet.2023.133321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
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7
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Schlenker K, Casselman LK, VanderLinden RT, Saouma CT. Large changes in hydricity as a function of charge and not metal in (PNP)M–H (de)hydrogenation catalysts that undergo metal–ligand cooperativity. Catal Sci Technol 2023. [DOI: 10.1039/d2cy01349e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Ligand pKa and metal hydricity scale with one another in (de)hydrogenation catalysts that undergo metal–ligand cooperativity, irrespective of metal or ligand identity. Anionic hydrides are significantly more hydridic than their neutral counterparts.
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Affiliation(s)
- Kevin Schlenker
- Department of Chemistry, University of Utah, Salt Lake City, Utah, 84112, USA
| | - Lillee K. Casselman
- Department of Chemistry, University of Utah, Salt Lake City, Utah, 84112, USA
| | | | - Caroline T. Saouma
- Department of Chemistry, University of Utah, Salt Lake City, Utah, 84112, USA
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8
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Matsuoka J, Fujimoto Y, Miyawaki A, Yamamoto Y. Phosphazene Base-Catalyzed Intramolecular Hydroamidation of Alkenes with Amides. Org Lett 2022; 24:9447-9451. [PMID: 36534049 DOI: 10.1021/acs.orglett.2c03870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
A method for the synthesis of cyclic amides via phosphazene base-catalyzed intramolecular hydroamidation of amide alkenes was developed. The reaction using a catalytic amount of P4-base had a good functional group tolerance and a broad substrate scope and could also be used to synthesize lactam, cyclic urea, and oxazolidinone compounds. This catalytic system was expanded to a one-pot intramolecular hydroamidation and intermolecular hydroalkylation. Deuterium labeling and radical trapping experiments provided mechanistic insights into the catalytic cycle of the hydroamidation reaction.
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Affiliation(s)
- Junpei Matsuoka
- Faculty of Pharmaceutical Sciences, Doshisha Women's College of Liberal Arts, Kodo, Kyotanabe 610-0395, Japan
| | - Yumika Fujimoto
- Faculty of Pharmaceutical Sciences, Doshisha Women's College of Liberal Arts, Kodo, Kyotanabe 610-0395, Japan
| | - Akari Miyawaki
- Faculty of Pharmaceutical Sciences, Doshisha Women's College of Liberal Arts, Kodo, Kyotanabe 610-0395, Japan
| | - Yasutomo Yamamoto
- Faculty of Pharmaceutical Sciences, Doshisha Women's College of Liberal Arts, Kodo, Kyotanabe 610-0395, Japan
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9
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Abstract
Cyclopropenium ions are the smallest class of aromatic compounds, satisfying Hückel's rules of aromaticity with two π electrons within a three-membered ring. First prepared by Breslow in 1957, cyclopropenium ions have been found to possess extraordinary stability despite being both cationic and highly strained. In the 65 years since their first preparation, cyclopropenium ions have been the subject of innumerable studies concerning their synthesis, physical properties, and reactivity. However, prior to our work, the reactivity of these unique carbocations had not been exploited for reaction promotion or catalysis.Over the past 13 years, we have been exploring aromatic ions as unique and versatile building blocks for the development of catalysts for organic chemistry. A major portion of this work has been focused on leveraging the remarkable properties of the smallest of the aromatic ions─cyclopropeniums─as a design element in the invention of highly reactive catalysts. Indeed, because of its unique profile of hydrolytic stability, compact geometry, and relatively easy oxidizability, the cyclopropenium ring has proven to be a highly advantageous construction module for catalyst invention.In this Account, we describe some of our work using cyclopropenium ions as a key element in the design of novel catalysts. First, we discuss our early work aimed at promoting dehydrative reactions, starting with Appel-type chlorodehydrations of alcohols and carboxylic acids, cyclic ether formations, and Beckmann rearrangements and culminating in the realization of catalytic chlorodehydrations of alcohols and a catalytic Mitsunobu-type reaction. Next, we describe the development of cyclopropenimines as strong, neutral organic Brønsted bases and, in particular, the use of chiral cyclopropenimines for enantioselective Brønsted catalysis. We also describe the development of higher-order cyclopropenimine superbases. The use of tris(amino)cyclopropenium (TAC) ions as a novel class of phase-transfer catalysts is discussed for the reaction of epoxides with carbon dioxide. Next, we describe the formation of a cyclopropenone radical cation that has a portion of its spin density on the oxygen atom, leading to some peculiar metal ligand behavior. Finally, we discuss recent work that employs TAC electrophotocatalysts for oxidation reactions. The key intermediate for this chemistry is a TAC radical dication, which as an open-shell photocatalyst has remarkably strong excited-state oxidizing power. We describe the application of this strategy to transformations ranging from the oxidative functionalization of unactivated arenes to the regioselective derivatization of ethers, C-H aminations, vicinal C-H diaminations, and finally aryl olefin dioxygenations. Collectively, these catalytic platforms demonstrate the utility of charged aromatic rings, and cyclopropenium ions in particular, to enable unique advances in catalysis.
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Affiliation(s)
- Rebecca M Wilson
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Tristan H Lambert
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
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10
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Dunn PL, Barona M, Johnson SI, Raugei S, Bullock RM. Hydrogen Atom Abstraction from an Os II(NH 3) 2 Complex Generates an Os IV(NH 2) 2 Complex: Experimental and Computational Analysis of the N-H Bond Dissociation Free Energies and Reactivity. Inorg Chem 2022; 61:15325-15334. [PMID: 36121917 DOI: 10.1021/acs.inorgchem.2c00708] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Double hydrogen atom abstraction from (TMP)OsII(NH3)2 (TMP = tetramesitylporphyrin) with phenoxyl or nitroxyl radicals leads to (TMP)OsIV(NH2)2. This unusual bis(amide) complex is diamagnetic and displays an N-H resonance at 12.0 ppm in its 1H NMR spectrum. 1H-15N correlation experiments identified a 15N NMR spectroscopic resonance signal at -267 ppm. Experimental reactivity studies and density functional theory calculations support relatively weak N-H bonds of 73.3 kcal/mol for (TMP)OsII(NH3)2 and 74.2 kcal/mol for (TMP)OsIII(NH3)(NH2). Cyclic voltammetry experiments provide an estimate of the pKa of [(TMP)OsIII(NH3)2]+. In the presence of Barton's base, a current enhancement is observed at the Os(III/II) couple, consistent with an ECE event. Spectroscopic experiments confirmed (TMP)OsIV(NH2)2 as the product of bulk electrolysis. Double hydrogen atom abstraction is influenced by π donation from the amides of (TMP)OsIV(NH2)2 into the d orbitals of the Os center, favoring the formation of (TMP)OsIV(NH2)2 over N-N coupling. This π donation leads to a Jahn-Teller distortion that splits the energy levels of the dxz and dyz orbitals of Os, results in a low-spin electron configuration, and leads to minimal aminyl character on the N atoms, rendering (TMP)OsIV(NH2)2 unreactive toward amide-amide coupling.
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Affiliation(s)
- Peter L Dunn
- Center for Molecular Electrocatalysis, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Melissa Barona
- Center for Molecular Electrocatalysis, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Samantha I Johnson
- Center for Molecular Electrocatalysis, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Simone Raugei
- Center for Molecular Electrocatalysis, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - R Morris Bullock
- Center for Molecular Electrocatalysis, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
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11
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Modeling pKa of the Brønsted Bases as an Approach to the Gibbs Energy of the Proton in Acetonitrile. Int J Mol Sci 2022; 23:ijms231810576. [PMID: 36142490 PMCID: PMC9502073 DOI: 10.3390/ijms231810576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Revised: 09/07/2022] [Accepted: 09/08/2022] [Indexed: 11/17/2022] Open
Abstract
A simple but efficient computational approach to calculate pKa in acetonitrile for a set of phosphorus, nitrogen, and carbon bases was established. A linear function that describes relations between the calculated ΔG’a.sol(BH+) and pKa values was determined for each group of bases. The best model was obtained through the variations in the basis set, in the level of theory (density functionals or MP2), and in the continuum solvation model (IPCM, CPCM, or SMD). The combination of the IPCM/B3LYP/6-311+G(d,p) solvation approach with MP2/6-311+G(2df,p)//B3LYP/6-31G(d) gas-phase energies provided very good results for all three groups of bases with R2 values close to or above 0.99. Interestingly, the slopes and the intercepts of the obtained linear functions showed significant deviations from the theoretical values. We made a linear plot utilizing all the conducted calculations and all the structural variations and employed methods to prove the systematic nature of the intercept/slope dependence. The interpolation of the intercept to the ideal slope value enabled us to determine the Gibbs energy of the proton in acetonitrile, which amounted to −258.8 kcal mol−1. The obtained value was in excellent agreement with previously published results.
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12
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Lee HB, Britt RD, Rittle J. N − H bond dissociation free energy of a terminal iron phosphinimine. J COORD CHEM 2022. [DOI: 10.1080/00958972.2022.2103411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
Affiliation(s)
- Heui Beom Lee
- Department of Chemistry, University of California Berkeley, Berkeley, CA, USA
| | - R. David Britt
- Department of Chemistry, University of California Davis, Davis, CA, USA
| | - Jonathan Rittle
- Department of Chemistry, University of California Berkeley, Berkeley, CA, USA
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13
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Radtke V, Gebel N, Priester D, Ermantraut A, Bäuerle M, Himmel D, Stroh R, Koslowski T, Leito I, Krossing I. Measurements and Utilization of Consistent Gibbs Energies of Transfer of Single Ions: Towards a Unified Redox Potential Scale for All Solvents. Chemistry 2022; 28:e202200509. [PMID: 35446995 PMCID: PMC9401597 DOI: 10.1002/chem.202200509] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Indexed: 11/08/2022]
Abstract
Utilizing the “ideal” ionic liquid salt bridge to measure Gibbs energies of transfer of silver ions between the solvents water, acetonitrile, propylene carbonate and dimethylformamide results in a consistent data set with a precision of 0.6 kJ mol−1 over 87 measurements in 10 half‐cells. This forms the basis for a coherent experimental thermodynamic framework of ion solvation chemistry. In addition, we define the solvent independent peabsH2O
‐ and the EabsH2O
values that account for the electronating potential of any redox system similar to the pHabsH2O
value of a medium that accounts for its protonating potential. This EabsH2O
scale is thermodynamically well‐defined enabling a straightforward comparison of the redox potentials (reducities) of all media with respect to the aqueous redox potential scale, hence unifying all conventional solvents′ redox potential scales. Thus, using the Gibbs energy of transfer of the silver ion published herein, one can convert and unify all hitherto published redox potentials measured, for example, against ferrocene, to the EabsH2O
scale.
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Affiliation(s)
- Valentin Radtke
- Institut für Anorganische und Analytische Chemie Freiburger Materialforschungszentrum (FMF) and Freiburg Center for Interactive Materials and Bioinspired Technologies (FIT) Albert-Ludwigs-Universität Freiburg Albertstr. 21 79104 Freiburg Germany
| | - Niklas Gebel
- Institut für Anorganische und Analytische Chemie Freiburger Materialforschungszentrum (FMF) and Freiburg Center for Interactive Materials and Bioinspired Technologies (FIT) Albert-Ludwigs-Universität Freiburg Albertstr. 21 79104 Freiburg Germany
| | - Denis Priester
- Institut für Anorganische und Analytische Chemie Freiburger Materialforschungszentrum (FMF) and Freiburg Center for Interactive Materials and Bioinspired Technologies (FIT) Albert-Ludwigs-Universität Freiburg Albertstr. 21 79104 Freiburg Germany
| | - Andreas Ermantraut
- Institut für Anorganische und Analytische Chemie Freiburger Materialforschungszentrum (FMF) and Freiburg Center for Interactive Materials and Bioinspired Technologies (FIT) Albert-Ludwigs-Universität Freiburg Albertstr. 21 79104 Freiburg Germany
| | - Monika Bäuerle
- Institut für Anorganische und Analytische Chemie Freiburger Materialforschungszentrum (FMF) and Freiburg Center for Interactive Materials and Bioinspired Technologies (FIT) Albert-Ludwigs-Universität Freiburg Albertstr. 21 79104 Freiburg Germany
| | - Daniel Himmel
- Institut für Anorganische und Analytische Chemie Freiburger Materialforschungszentrum (FMF) and Freiburg Center for Interactive Materials and Bioinspired Technologies (FIT) Albert-Ludwigs-Universität Freiburg Albertstr. 21 79104 Freiburg Germany
| | - Regina Stroh
- Institut für Anorganische und Analytische Chemie Freiburger Materialforschungszentrum (FMF) and Freiburg Center for Interactive Materials and Bioinspired Technologies (FIT) Albert-Ludwigs-Universität Freiburg Albertstr. 21 79104 Freiburg Germany
| | - Thorsten Koslowski
- Institut für Physikalische Chemie Albert-Ludwigs-Universität Freiburg Albertstr. 23a 79104 Freiburg Germany
| | - Ivo Leito
- Institute of Chemistry University of Tartu Ravila 14a Str 50411 Tartu Estonia
| | - Ingo Krossing
- Institut für Anorganische und Analytische Chemie Freiburger Materialforschungszentrum (FMF) and Freiburg Center for Interactive Materials and Bioinspired Technologies (FIT) Albert-Ludwigs-Universität Freiburg Albertstr. 21 79104 Freiburg Germany
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14
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Kulsha AV, Ragoyja EG, Ivashkevich OA. Strong Bases Design: Predicted Limits of Basicity. J Phys Chem A 2022; 126:3642-3652. [PMID: 35657384 DOI: 10.1021/acs.jpca.2c00521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Brønsted superbases have wide applications in organic chemistry due to their ability to activate C-H bonds. The strongest neutral bases to date are substituted aminophosphazenes developed in the late 1980s by Reinhard Schwesinger. Since then, much effort has been expended to create even stronger neutral bases. In this article, the reasons for the instability of very basic compounds are investigated by means of high-level quantum-chemical calculations. Theoretical basicity limits are suggested for solutions as well as for the gas phase. A record-breaking superbase most likely to be synthesizable and stable at ambient conditions is proposed. Hexamethylphosphoramide is considered a reliable ionizing solvent for superbases.
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Affiliation(s)
- Andrey V Kulsha
- Chemical Department, Belarusian State University, 4 Nezavisimosti Avenue, 220030 Minsk, Republic of Belarus
| | - Ekaterina G Ragoyja
- Chemical Department, Belarusian State University, 4 Nezavisimosti Avenue, 220030 Minsk, Republic of Belarus
| | - Oleg A Ivashkevich
- Laboratory for Chemistry of Condensed Systems, Research Institute for Physical Chemical Problems of the Belarusian State University, 14 Leningradskaya Street, 220006 Minsk, Republic of Belarus
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15
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Cobo J, Molina S, Sánchez A, Nogueras M, Insuasty B, Orozco‐López F. Reactivity of Pyrimidinylphosphazenes with Acetylenic Esters: Competitive [4+2] and [2+2] Tandem Cycloaddition/Retro‐cycloaddition Approaches. J Heterocycl Chem 2022. [DOI: 10.1002/jhet.4487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Justo Cobo
- Departamento de Química Inorgánica y Orgánica Grupo de Investigación en Compuestos de Interés Biológico, Universidad de Jaén Jaén Spain
| | - Sebastián Molina
- Departamento de Química Inorgánica y Orgánica Grupo de Investigación en Compuestos de Interés Biológico, Universidad de Jaén Jaén Spain
| | - Adolfo Sánchez
- Departamento de Química Inorgánica y Orgánica Grupo de Investigación en Compuestos de Interés Biológico, Universidad de Jaén Jaén Spain
| | - Manuel Nogueras
- Departamento de Química Inorgánica y Orgánica Grupo de Investigación en Compuestos de Interés Biológico, Universidad de Jaén Jaén Spain
| | - Braulio Insuasty
- Departamento de Química Grupo de Investigación de Compuestos Heterocíclicos, Universidad del Valle Cali Colombia
| | - Fabián Orozco‐López
- Grupo de Estudios en Síntesis y Aplicaciones de Compuestos Heterocíclicos, Departamento de Química, Universidad Nacional de Colombia Bogotá Colombia
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16
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Matsuoka J, Terashita M, Miyawaki A, Tomioka K, Yamamoto Y. Phosphazene base-catalyzed hydroamination of aminoalkenes for the construction of isoindoline scaffolds: Application to the total synthesis of aristocularine. Tetrahedron Lett 2022. [DOI: 10.1016/j.tetlet.2021.153599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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17
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Abstract
Carbide complexes remain a rare class of molecules. Their paucity does not reflect exceptional instability but is rather due to the generally narrow scope of synthetic procedures for constructing carbide complexes. The preparation of carbide complexes typically revolves around generating LnM-CEx fragments, followed by cleavage of the C-E bonds of the coordinated carbon-based ligands (the alternative being direct C atom transfer). Prime examples involve deoxygenation of carbonyl ligands and deprotonation of methyl ligands, but several other p-block fragments can be cleaved off to afford carbide ligands. This Review outlines synthetic strategies toward terminal carbide complexes, bridging carbide complexes, as well as carbide-carbonyl cluster complexes. It then surveys the reactivity of carbide complexes, covering stoichiometric reactions where the carbide ligands act as C1 reagents, engage in cross-coupling reactions, and enact Fischer-Tropsch-like chemistry; in addition, we discuss carbide complexes in the context of catalysis. Finally, we examine spectroscopic features of carbide complexes, which helps to establish the presence of the carbide functionality and address its electronic structure.
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Affiliation(s)
- Anders Reinholdt
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen, Denmark
| | - Jesper Bendix
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen, Denmark
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18
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Buß F, Röthel MB, Werra JA, Rotering P, Wilm LFB, Daniliuc CG, Löwe P, Dielmann F. Tris(tetramethylguanidinyl)phosphine: The Simplest Non-ionic Phosphorus Superbase and Strongly Donating Phosphine Ligand. Chemistry 2021; 28:e202104021. [PMID: 34793627 PMCID: PMC9300019 DOI: 10.1002/chem.202104021] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Indexed: 12/13/2022]
Abstract
We report the synthesis and properties of the much sought‐after tris(1,1,3,3‐tetramethylguanidinyl) phosphine P(tmg)3, a crystalline, superbasic phosphine accessible through a short and scalable procedure from the cheap and commercially available bulk chemicals 1,1,3,3‐tetramethylguanidine, tris(dimethylamino)‐phosphine and phosphorus trichloride. The new phosphine exhibits exceptional electron donor properties and readily forms transition metal complexes with gold(I), palladium(II) and rhodium(I) precursors. The formation of zwitterionic Lewis base adducts with carbon dioxide and sulfur dioxide was explored. In addition, the complete series of phosphine chalcogenides was prepared from the reaction of P(tmg)3 with N2O and the elemental chalcogens.
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Affiliation(s)
- Florenz Buß
- Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstraße 28-30, 48149, Münster, Germany
| | - Maike B Röthel
- Institute of General, Inorganic and Theoretical Chemistry, University of Innsbruck, Center for Chemistry and Biomedicine, Innrain 80-82, A-6020, Innsbruck, Austria
| | - Janina A Werra
- Institute of General, Inorganic and Theoretical Chemistry, University of Innsbruck, Center for Chemistry and Biomedicine, Innrain 80-82, A-6020, Innsbruck, Austria
| | - Philipp Rotering
- Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstraße 28-30, 48149, Münster, Germany
| | - Lukas F B Wilm
- Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstraße 28-30, 48149, Münster, Germany
| | - Constantin G Daniliuc
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstraße 40, 48149, Münster, Germany
| | - Pawel Löwe
- Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstraße 28-30, 48149, Münster, Germany
| | - Fabian Dielmann
- Institute of General, Inorganic and Theoretical Chemistry, University of Innsbruck, Center for Chemistry and Biomedicine, Innrain 80-82, A-6020, Innsbruck, Austria
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19
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Vermersch F, Yazdani S, Junor GP, Grotjahn DB, Jazzar R, Bertrand G. Stable Singlet Carbenes as Organic Superbases. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202111588] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- François Vermersch
- UCSD-CNRS Joint Research Laboratory (IRL 3555) Department of Chemistry and Biochemistry University of California San Diego, La Jolla CA 92093-0358 USA
| | - Sima Yazdani
- UCSD-CNRS Joint Research Laboratory (IRL 3555) Department of Chemistry and Biochemistry University of California San Diego, La Jolla CA 92093-0358 USA
- Department of Chemistry and Biochemistry San Diego State University 5500 Campanile Drive San Diego CA 92182-1030 USA
| | - Glen P. Junor
- UCSD-CNRS Joint Research Laboratory (IRL 3555) Department of Chemistry and Biochemistry University of California San Diego, La Jolla CA 92093-0358 USA
| | - Douglas B. Grotjahn
- Department of Chemistry and Biochemistry San Diego State University 5500 Campanile Drive San Diego CA 92182-1030 USA
| | - Rodolphe Jazzar
- UCSD-CNRS Joint Research Laboratory (IRL 3555) Department of Chemistry and Biochemistry University of California San Diego, La Jolla CA 92093-0358 USA
| | - Guy Bertrand
- UCSD-CNRS Joint Research Laboratory (IRL 3555) Department of Chemistry and Biochemistry University of California San Diego, La Jolla CA 92093-0358 USA
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20
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Vermersch F, Yazdani S, Junor GP, Grotjahn DB, Jazzar R, Bertrand G. Stable Singlet Carbenes as Organic Superbases. Angew Chem Int Ed Engl 2021; 60:27253-27257. [PMID: 34729888 DOI: 10.1002/anie.202111588] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 10/18/2021] [Indexed: 11/10/2022]
Abstract
A simple experimental procedure for scaling carbene Brønsted basicity is described. The results highlight the strong basicity of pyrazol-4-ylidenes, a type of mesoionic carbene, also named cyclic-bentallenes (CBA). They are more basic (pKaH >42.7 in acetonitrile) than the popular proazaphosphatrane Verkade bases, and even the Schwesinger phosphazene superbase P4 (t Bu). The basicity of these compounds can readily be tuned, and they are accessible in multigram quantities. These results open new avenues for carbon centered superbases.
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Affiliation(s)
- François Vermersch
- UCSD-CNRS Joint Research Laboratory (IRL 3555), Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA, 92093-0358, USA
| | - Sima Yazdani
- UCSD-CNRS Joint Research Laboratory (IRL 3555), Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA, 92093-0358, USA.,Department of Chemistry and Biochemistry, San Diego State University, 5500 Campanile Drive, San Diego, CA, 92182-1030, USA
| | - Glen P Junor
- UCSD-CNRS Joint Research Laboratory (IRL 3555), Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA, 92093-0358, USA
| | - Douglas B Grotjahn
- Department of Chemistry and Biochemistry, San Diego State University, 5500 Campanile Drive, San Diego, CA, 92182-1030, USA
| | - Rodolphe Jazzar
- UCSD-CNRS Joint Research Laboratory (IRL 3555), Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA, 92093-0358, USA
| | - Guy Bertrand
- UCSD-CNRS Joint Research Laboratory (IRL 3555), Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA, 92093-0358, USA
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21
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Lee HB, Ciolkowski N, Winslow C, Rittle J. High Spin Cobalt Complexes Supported by a Trigonal Tris(Phosphinimide) Ligand. Inorg Chem 2021; 60:11830-11837. [PMID: 34320321 DOI: 10.1021/acs.inorgchem.1c01400] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Terminal, π-basic moieties occupy a prominent position in the stabilization of unusual or reactive inorganic species. The electron-releasing, π-basic properties of phosphinimides (PN) have been employed to stabilize electron-deficient early transition metals and lanthanides. In principle, a ligand field comprised of terminal PN groups should enable access to high-valent states of late first row transition metals. Herein, we report a new class of multidentate phosphinimide ligands to logically explore this hypothesis. Access to such ligands is made possible by a new procedure for the electrophilic amination of rigid, sterically encumbering, multidentate phosphines. Such frameworks facilitate terminal PN coordination to cobalt as demonstrated by the synthesis of a trinuclear CoII3 complex and a homoleptic, three-coordinate CoIII complex. Interestingly, the CoIII complex exhibits an exceedingly rare S = 2 ground state. Combined XRD, magnetic susceptibility, and DFT studies highlight that terminally bound PNs engage in strong dπ-pπ interactions that present a weak ligand field appropriate to stabilize high-spin states of late transition metals.
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Affiliation(s)
- Heui Beom Lee
- Department of Chemistry, University of California Berkeley, Berkeley, California 94720, United States
| | - Nicholas Ciolkowski
- Department of Chemistry, University of California Berkeley, Berkeley, California 94720, United States
| | - Charles Winslow
- Department of Chemistry, University of California Berkeley, Berkeley, California 94720, United States
| | - Jonathan Rittle
- Department of Chemistry, University of California Berkeley, Berkeley, California 94720, United States
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22
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Vazdar K, Margetić D, Kovačević B, Sundermeyer J, Leito I, Jahn U. Design of Novel Uncharged Organic Superbases: Merging Basicity and Functionality. Acc Chem Res 2021; 54:3108-3123. [PMID: 34308625 DOI: 10.1021/acs.accounts.1c00297] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
ConspectusOne of the constant challenges of synthetic chemistry is the molecular design and synthesis of nonionic, metal-free superbases as chemically stable neutral organic compounds of moderate molecular weight, intrinsically high thermodynamic basicity, adaptable kinetic basicity, and weak or tunable nucleophilicity at their nitrogen, phosphorus, or carbon basicity centers. Such superbases can catalyze numerous reactions, ranging from C-C bond formation to cycloadditions and polymerization, to name just a few. Additional benefits of organic superbases, as opposed to their inorganic counterparts, are their solubility in organic reaction media, mild reaction conditions, and higher selectivity. Approaching such superbasic compounds remains a continuous challenge. However, recent advances in synthetic methodology and theoretical understanding have resulted in new design principles and synthetic strategies toward superbases. Our computational contributions have demonstrated that the gas-phase basicity region of 350 kcal mol-1 and even beyond is easily reachable by organosuperbases. However, despite record-high basicities, the physical limitations of many of these compounds become quickly evident. The typically large molecular weight of these molecules and their sensitivity to ordinary reaction conditions prevent them from being practical, even though their preparation is often not too difficult. Thus, obviously structural limitations with respect to molecular weight and structural complexity must be imposed on the design of new synthetically useful organic superbases, but strategies for increasing their basicity remain important.The contemporary design of novel organic superbases is illustrated by phosphazenyl phosphanes displaying gas-phase basicities (GB) above 300 kcal mol-1 but having molecular weights well below 1000 g·mol-1. This approach is based on a reconsideration of phosphorus(III) compounds, which goes along with increasing their stability in solution. Another example is the preparation of carbodiphosphoranes incorporating pyrrolidine, tetramethylguanidine, or hexamethylphosphazene as a substituent. With gas-phase proton affinities of up to 300 kcal mol-1, they are among the top nonionic carbon bases on the basicity scale. Remarkably, the high basicity of these compounds is achieved at molecular weights of around 600 g·mol-1. Another approach to achieving high basicity through the cooperative effect of multiple intramolecular hydrogen bonding, which increases the stabilization of conjugate acids, has recently been confirmed.This Account focuses on our efforts to produce superbasic molecules that embody many desirable traits, but other groups' approaches will also be discussed. We reveal the crucial structural features of superbases and place them on known basicity scales. We discuss the emerging potential and current limits of their application and give a general outlook into the future.
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Affiliation(s)
- Katarina Vazdar
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, v.v.i. Flemingovo nám. 2, 166 10 Prague 6, Czech Republic
| | | | | | - Jörg Sundermeyer
- Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Straße, 35032 Marburg, Germany
| | - Ivo Leito
- Institute of Chemistry, University of Tartu, Ravila 14a, 50411 Tartu, Estonia
| | - Ullrich Jahn
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, v.v.i. Flemingovo nám. 2, 166 10 Prague 6, Czech Republic
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23
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Weitkamp RF, Neumann B, Stammler H, Hoge B. Phosphorus-Containing Superbases: Recent Progress in the Chemistry of Electron-Abundant Phosphines and Phosphazenes. Chemistry 2021; 27:10807-10825. [PMID: 34032319 PMCID: PMC8362139 DOI: 10.1002/chem.202101065] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Indexed: 01/11/2023]
Abstract
The renaissance of Brønsted superbases is primarily based on their pronounced capacity for a large variety of chemical transformations under mild reaction conditions. Four major set screws are available for the selective tuning of the basicity: the nature of the basic center (N, P, …), the degree of electron donation by substituents to the central atom, the possibility of charge delocalization, and the energy gain by hydrogen bonding. Within the past decades, a plethora of neutral electron-rich phosphine and phosphazene bases have appeared in the literature. Their outstanding properties and advantages over inorganic or charged bases have now made them indispensable as auxiliary bases in deprotonation processes. Herein, an update of the chemistry of basic phosphines and phosphazenes is given. In addition, due to widespread interest, their use in catalysis or as ligands in coordination chemistry is highlighted.
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Affiliation(s)
- Robin F. Weitkamp
- Centrum für Molekulare MaterialienFakultät für ChemieUniversität BielefeldUniversitätsstraße 2533615BielefeldGermany
| | - Beate Neumann
- Centrum für Molekulare MaterialienFakultät für ChemieUniversität BielefeldUniversitätsstraße 2533615BielefeldGermany
| | - Hans‐Georg Stammler
- Centrum für Molekulare MaterialienFakultät für ChemieUniversität BielefeldUniversitätsstraße 2533615BielefeldGermany
| | - Berthold Hoge
- Centrum für Molekulare MaterialienFakultät für ChemieUniversität BielefeldUniversitätsstraße 2533615BielefeldGermany
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24
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Schlenker K, Christensen EG, Zhanserkeev AA, McDonald GR, Yang EL, Lutz KT, Steele RP, VanderLinden RT, Saouma CT. Role of Ligand-Bound CO 2 in the Hydrogenation of CO 2 to Formate with a (PNP)Mn Catalyst. ACS Catal 2021. [DOI: 10.1021/acscatal.1c01709] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Kevin Schlenker
- Department of Chemistry, University of Utah, 315 S. 1400 E., Salt Lake City, Utah 84112, United States
| | - Elizabeth G. Christensen
- Department of Chemistry, University of Utah, 315 S. 1400 E., Salt Lake City, Utah 84112, United States
| | - Asylbek A. Zhanserkeev
- Department of Chemistry, University of Utah, 315 S. 1400 E., Salt Lake City, Utah 84112, United States
| | - Gabriel R. McDonald
- Department of Chemistry, University of Utah, 315 S. 1400 E., Salt Lake City, Utah 84112, United States
| | - Emily L. Yang
- Department of Chemistry, University of Utah, 315 S. 1400 E., Salt Lake City, Utah 84112, United States
| | - Kevin T. Lutz
- Department of Chemistry, University of Utah, 315 S. 1400 E., Salt Lake City, Utah 84112, United States
| | - Ryan P. Steele
- Department of Chemistry, University of Utah, 315 S. 1400 E., Salt Lake City, Utah 84112, United States
| | - Ryan T. VanderLinden
- Department of Chemistry, University of Utah, 315 S. 1400 E., Salt Lake City, Utah 84112, United States
| | - Caroline T. Saouma
- Department of Chemistry, University of Utah, 315 S. 1400 E., Salt Lake City, Utah 84112, United States
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25
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Phosphazene superbase mediated cyclization and annulation reactions of functionalized alkynes for the synthesis of heterocyclic compounds. Chem Heterocycl Compd (N Y) 2021. [DOI: 10.1007/s10593-021-02898-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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26
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McLoughlin EA, Armstrong KC, Waymouth RM. Electrochemically Regenerable Hydrogen Atom Acceptors: Mediators in Electrocatalytic Alcohol Oxidation Reactions. ACS Catal 2020. [DOI: 10.1021/acscatal.0c03240] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
| | - Keith C. Armstrong
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Robert M. Waymouth
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
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27
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Jung ST, Podlech J. Development of a Robust Protocol for the Determination of Weak Acids’ p Ka Values in DMSO. J Org Chem 2020; 85:10951-10957. [DOI: 10.1021/acs.joc.0c00909] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Sebastian T. Jung
- Institut für Organische Chemie, Karlsruher Institut für Technologie (KIT), Fritz-Haber-Weg 6, 76131 Karlsruhe, Germany
| | - Joachim Podlech
- Institut für Organische Chemie, Karlsruher Institut für Technologie (KIT), Fritz-Haber-Weg 6, 76131 Karlsruhe, Germany
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28
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Vitkovskaya NM, Orel VB, Absalyamov DZ, Trofimov BA. Self-Assembly of N-Phenyl-2,5-dimethylpyrrole from Acetylene and Aniline in KOH/DMSO and KOBut/DMSO Superbase Systems: A Quantum-Chemical Insight. J Org Chem 2020; 85:10617-10627. [DOI: 10.1021/acs.joc.0c01185] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Nadezhda M. Vitkovskaya
- Laboratory of Quantum Chemical Modeling of Molecular Systems, Irkutsk State University, 1 K. Marks St., Irkutsk 664003, Russian Federation
| | - Vladimir B. Orel
- Laboratory of Quantum Chemical Modeling of Molecular Systems, Irkutsk State University, 1 K. Marks St., Irkutsk 664003, Russian Federation
| | - Damir Z. Absalyamov
- Laboratory of Quantum Chemical Modeling of Molecular Systems, Irkutsk State University, 1 K. Marks St., Irkutsk 664003, Russian Federation
- A.E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, 1 Favorsky St., Irkutsk 664033, Russian Federation
| | - Boris A. Trofimov
- A.E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, 1 Favorsky St., Irkutsk 664033, Russian Federation
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29
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Vollmer MV, Ye J, Linehan JC, Graziano BJ, Preston A, Wiedner ES, Lu CC. Cobalt-Group 13 Complexes Catalyze CO2 Hydrogenation via a Co(−I)/Co(I) Redox Cycle. ACS Catal 2020. [DOI: 10.1021/acscatal.9b03534] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Matthew V. Vollmer
- Department of Chemistry, University of Minnesota−Twin Cities, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
| | - Jingyun Ye
- Department of Chemistry, University of Minnesota−Twin Cities, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
- Supercomputing Institute, and Chemical Theory Center, University of Minnesota−Twin Cities, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
| | - John C. Linehan
- Catalysis Science Group, Pacific Northwest National Laboratory, P.O. Box 999, MS K2-57, Richland, Washington 99352, United States
| | - Brendan J. Graziano
- Department of Chemistry, University of Minnesota−Twin Cities, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
| | - Andrew Preston
- Catalysis Science Group, Pacific Northwest National Laboratory, P.O. Box 999, MS K2-57, Richland, Washington 99352, United States
| | - Eric S. Wiedner
- Catalysis Science Group, Pacific Northwest National Laboratory, P.O. Box 999, MS K2-57, Richland, Washington 99352, United States
| | - Connie C. Lu
- Department of Chemistry, University of Minnesota−Twin Cities, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
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30
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Tshepelevitsh S, Kütt A, Lõkov M, Kaljurand I, Saame J, Heering A, Plieger PG, Vianello R, Leito I. On the Basicity of Organic Bases in Different Media. European J Org Chem 2019. [DOI: 10.1002/ejoc.201900956] [Citation(s) in RCA: 154] [Impact Index Per Article: 30.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
| | - Agnes Kütt
- Institute of Chemistry; University of Tartu; Ravila 14a 50411 Tartu Estonia
| | - Märt Lõkov
- Institute of Chemistry; University of Tartu; Ravila 14a 50411 Tartu Estonia
| | - Ivari Kaljurand
- Institute of Chemistry; University of Tartu; Ravila 14a 50411 Tartu Estonia
| | - Jaan Saame
- Institute of Chemistry; University of Tartu; Ravila 14a 50411 Tartu Estonia
| | - Agnes Heering
- Institute of Chemistry; University of Tartu; Ravila 14a 50411 Tartu Estonia
| | - Paul G. Plieger
- School of Fundamental Sciences; Massey University; Private Bag 11 222 Palmerston North New Zealand
| | - Robert Vianello
- Computational Organic Chemistry and Biochemistry Group; Ruđer Bošković Institute; Bijenička cesta 54 10000 Zagreb Croatia
| | - Ivo Leito
- Institute of Chemistry; University of Tartu; Ravila 14a 50411 Tartu Estonia
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31
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Buss JA, Bailey GA, Oppenheim J, VanderVelde DG, Goddard WA, Agapie T. CO Coupling Chemistry of a Terminal Mo Carbide: Sequential Addition of Proton, Hydride, and CO Releases Ethenone. J Am Chem Soc 2019; 141:15664-15674. [DOI: 10.1021/jacs.9b07743] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Joshua A. Buss
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Boulevard MC 127-72, Pasadena, California 91125, United States
| | - Gwendolyn A. Bailey
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Boulevard MC 127-72, Pasadena, California 91125, United States
| | - Julius Oppenheim
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Boulevard MC 127-72, Pasadena, California 91125, United States
| | - David G. VanderVelde
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Boulevard MC 127-72, Pasadena, California 91125, United States
| | - William A. Goddard
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Boulevard MC 127-72, Pasadena, California 91125, United States
| | - Theodor Agapie
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Boulevard MC 127-72, Pasadena, California 91125, United States
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Ullrich S, Kovačević B, Koch B, Harms K, Sundermeyer J. Design of non-ionic carbon superbases: second generation carbodiphosphoranes. Chem Sci 2019; 10:9483-9492. [PMID: 32055322 PMCID: PMC6993619 DOI: 10.1039/c9sc03565f] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Accepted: 08/15/2019] [Indexed: 12/31/2022] Open
Abstract
The edge-cutting design, synthesis and characterization of the so far strongest non-ionic carbon superbases is presented.
A new generation of carbodiphosphoranes (CDPs), incorporating pyrrolidine, tetramethylguanidine, or tris(dimethylamino)phosphazene as substituents is introduced as the most powerful class of non-ionic carbon superbases on the basicity scale to date. The synthetic approach as well as NMR spectroscopic and structural characteristics in the free and protonated form are described. Investigation of basicity in solution and in the gas phase by experimental and theoretical means provides the to our knowledge first reported pKBH+ values for CDPs in the literature and suggest them as upper tier superbases.
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Affiliation(s)
- Sebastian Ullrich
- Fachbereich Chemie , Philipps-University Marburg , Hans-Meerwein-Straße , 35032 Marburg , Germany .
| | - Borislav Kovačević
- The Group for Computational Life Sciences , Rudjer Bošković Institute , Bijenička c. 54 , HR-10000 Zagreb , Croatia
| | - Björn Koch
- Fachbereich Chemie , Philipps-University Marburg , Hans-Meerwein-Straße , 35032 Marburg , Germany .
| | - Klaus Harms
- Fachbereich Chemie , Philipps-University Marburg , Hans-Meerwein-Straße , 35032 Marburg , Germany .
| | - Jörg Sundermeyer
- Fachbereich Chemie , Philipps-University Marburg , Hans-Meerwein-Straße , 35032 Marburg , Germany .
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Ullrich S, Kovačević B, Xie X, Sundermeyer J. Phosphazenyl Phosphines: The Most Electron‐Rich Uncharged Phosphorus Brønsted and Lewis Bases. Angew Chem Int Ed Engl 2019; 58:10335-10339. [DOI: 10.1002/anie.201903342] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 04/29/2019] [Indexed: 01/15/2023]
Affiliation(s)
- Sebastian Ullrich
- Fachbereich ChemiePhilipps-Universität Marburg Hans-Meerwein-Straße 35032 Marburg Germany
| | - Borislav Kovačević
- The Group for Computational Life SciencesRudjer Bošković Institute Bijenička c. 54 10000 Zagreb Croatia
| | - Xiulan Xie
- Fachbereich ChemiePhilipps-Universität Marburg Hans-Meerwein-Straße 35032 Marburg Germany
| | - Jörg Sundermeyer
- Fachbereich ChemiePhilipps-Universität Marburg Hans-Meerwein-Straße 35032 Marburg Germany
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34
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Ullrich S, Kovačević B, Xie X, Sundermeyer J. Phosphazenylphosphine: Die elektronenreichsten ungeladenen Brønsted‐ und Lewis‐Phosphor‐Basen. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201903342] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- Sebastian Ullrich
- Fachbereich ChemiePhilipps-Universität Marburg Hans-Meerwein-Straße 35032 Marburg Deutschland
| | - Borislav Kovačević
- The Group for Computational Life SciencesRudjer Bošković Institute Bijenička 54 HR-10000 Zagreb Kroatien
| | - Xiulan Xie
- Fachbereich ChemiePhilipps-Universität Marburg Hans-Meerwein-Straße 35032 Marburg Deutschland
| | - Jörg Sundermeyer
- Fachbereich ChemiePhilipps-Universität Marburg Hans-Meerwein-Straße 35032 Marburg Deutschland
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35
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Mehta S, Brahmchari D. Phosphazene Superbase-Mediated Regio- and Stereoselective Iodoaminocyclization of 2-(1-Alkynyl)benzamides for the Synthesis of Isoindolin-1-ones. J Org Chem 2019; 84:5492-5503. [DOI: 10.1021/acs.joc.9b00452] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Saurabh Mehta
- Department of Applied Chemistry, Delhi Technological University, Delhi, 110042, India
| | - Dhirendra Brahmchari
- Department of Applied Chemistry, Delhi Technological University, Delhi, 110042, India
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36
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Barišić D, Tomišić V, Bregović N. Acid-base properties of phosphoric and acetic acid in aprotic organic solvents - A complete thermodynamic characterisation. Anal Chim Acta 2019; 1046:77-92. [PMID: 30482305 DOI: 10.1016/j.aca.2018.09.026] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Revised: 08/28/2018] [Accepted: 09/13/2018] [Indexed: 01/15/2023]
Abstract
Knowledge regarding the acid-base behaviour in non-aqueous media has remained relatively scarce in spite of its importance for many aspects of chemistry. The research presented in this work fills some of particularly important gaps in the corresponding thermodynamic data. We report on a detailed study of acid-base properties of dihydrogen phosphate and acetate in aprotic organic solvents (acetonitrile, dimethyl sulfoxide, and dimethylformamide). It was found that several processes, i.e. protonation, homoassociation, and dimerisation play important roles in defining the basicity of these widely important anions. In the case of dihydrogen phosphate, formation of higher homoassociates (two anions, one acid molecule and vice versa) was detected, whereas acetate formed only simple homoassociates of 1:1 stoichiometry. The dimerisation of dihydrogen phosphate and acetic acid were confirmed to be important processes as well. The thermodynamics of the above mentioned reactions was characterised in detail by means of various experimental methods: ITC, spectrophotometry, NMR-spectroscopy, and conductometry. Reliable equilibrium constants and other thermodynamic reaction functions were determined. The obtained results were discussed in terms of hydrogen bonding potential of the anions and their conjugated acids, as well as solvent properties, i.e. their ability to solvate the species involved in the studied processes.
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Affiliation(s)
- D Barišić
- Department of Chemistry, Faculty of Science, University of Zagreb, Horvatovac 102a, 10000, Zagreb, Croatia; Division of Physical Chemistry, Ruđer Bošković Institute, Bijenička cesta 54, 10000, Zagreb, Croatia
| | - V Tomišić
- Department of Chemistry, Faculty of Science, University of Zagreb, Horvatovac 102a, 10000, Zagreb, Croatia
| | - N Bregović
- Department of Chemistry, Faculty of Science, University of Zagreb, Horvatovac 102a, 10000, Zagreb, Croatia.
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37
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Abstract
The acidity ladder scale in [BMPY][NTf2] was successfully expanded toward the weak acidity region for about five more p K units compared to the previously established one. This allows the acidities of a series of 13 aliphatic and aromatic nitroalkanes to be determined accurately by the UV-vis spectroscopic method. The acidity of nitroalkane in [BMPY][NTf2] covers ∼8 p K units and is significantly weaker than those in DMSO and water. The Hammett plot for 4-substituted phenylnitromethanes shows an excellent linearity with a slope of 2.06, which is rather close to that in DMSO but significantly larger than that in water (0.80). The regression analyses reveal that the solvation behavior of [BMPY][NTf2] on the acidic dissociations of C-H acids is similar to that of DMSO.
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Affiliation(s)
- Feixiang Gao
- Center of Basic Molecular Science (CBMS), Department of Chemistry , Tsinghua University , Beijing 100084 , China
| | - Pengju Ji
- Center of Basic Molecular Science (CBMS), Department of Chemistry , Tsinghua University , Beijing 100084 , China
| | - Jin-Pei Cheng
- Center of Basic Molecular Science (CBMS), Department of Chemistry , Tsinghua University , Beijing 100084 , China.,State Key Laboratory of Elemento-Organic Chemistry, Collaborative Innovation Center of Chemical Science and Engineering , Nankai University , Tianjin 300071 , China
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38
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Hong M, Chen J, Chen EYX. Polymerization of Polar Monomers Mediated by Main-Group Lewis Acid-Base Pairs. Chem Rev 2018; 118:10551-10616. [PMID: 30350583 DOI: 10.1021/acs.chemrev.8b00352] [Citation(s) in RCA: 170] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The development of new or more sustainable, active, efficient, controlled, and selective polymerization reactions or processes continues to be crucial for the synthesis of important polymers or materials with specific structures or functions. In this context, the newly emerged polymerization technique enabled by main-group Lewis pairs (LPs), termed as Lewis pair polymerization (LPP), exploits the synergy and cooperativity between the Lewis acid (LA) and Lewis base (LB) sites of LPs, which can be employed as frustrated Lewis pairs (FLPs), interacting LPs (ILPs), or classical Lewis adducts (CLAs), to effect cooperative monomer activation as well as chain initiation, propagation, termination, and transfer events. Through balancing the Lewis acidity, Lewis basicity, and steric effects of LPs, LPP has shown several unique advantages or intriguing opportunities compared to other polymerization techniques and demonstrated its broad polar monomer scope, high activity, control or livingness, and complete chemo- or regioselectivity, as well as its unique application in materials chemistry. These advances made in LPP are comprehensively reviewed, with the scope of monomers focusing on heteroatom-containing polar monomers, while the polymerizations mediated by main-group LAs and LBs separately that are most relevant to the LPP are also highlighted or updated. Examples of applying the principles of the LPP and LP chemistry as a new platform for advancing materials chemistry are highlighted, and currently unmet challenges in the field of the LPP, and thus the suggested corresponding future research directions, are also presented.
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Affiliation(s)
- Miao Hong
- State Key Laboratory of Organometallic Chemistry , Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences , Shanghai 200032 , China
| | - Jiawei Chen
- Department of Chemistry , Columbia University , 3000 Broadway , New York , New York 10027 , United States
| | - Eugene Y-X Chen
- Department of Chemistry , Colorado State University , Fort Collins , Colorado 80523 , United States
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39
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40
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Tandarić T, Vianello R. Design of Exceptionally Strong Organic Superbases Based on Aromatic Pnictogen Oxides: Computational DFT Analysis of the Oxygen Basicity in the Gas Phase and Acetonitrile Solution. J Phys Chem A 2018; 122:1464-1471. [DOI: 10.1021/acs.jpca.7b11945] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Tana Tandarić
- Computational Organic Chemistry and Biochemistry Group, Rud̵er Bošković Institute, Zagreb 10000, Croatia
| | - Robert Vianello
- Computational Organic Chemistry and Biochemistry Group, Rud̵er Bošković Institute, Zagreb 10000, Croatia
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41
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Teearu A, Vahur S, Rodima T, Herodes K, Bonrath W, Netscher T, Tshepelevitsh S, Trummal A, Lõkov M, Leito I. Method development for the analysis of resinous materials with MALDI-FT-ICR-MS: novel internal standards and a new matrix material for negative ion mode. JOURNAL OF MASS SPECTROMETRY : JMS 2017; 52:603-617. [PMID: 28471541 DOI: 10.1002/jms.3943] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Revised: 04/18/2017] [Accepted: 05/01/2017] [Indexed: 06/07/2023]
Abstract
Matrix-assisted laser desorption/ionization (MALDI) is a mass spectrometry (MS) ionization technique suitable for a wide variety of sample types including highly complex ones such as natural resinous materials. Coupled with Fourier transform ion cyclotron resonance (FT-ICR) mass analyser, which provides mass spectra with high resolution and accuracy, the method gives a wealth of information about the composition of the sample. One of the key aspects in MALDI-MS is the right choice of matrix compound. We have previously demonstrated that 2,5-dihydroxybenzoic acid is suitable for the positive ion mode analysis of resinous samples. However, 2,5-dihydroxybenzoic acid was found to be unsuitable for the analysis of these samples in the negative ion mode. The second problem addressed was the limited choice of calibration standards offering a flexible selection of m/z values under m/z 1000. This study presents a modified MALDI-FT-ICR-MS method for the analysis of resinous materials, which incorporates a novel matrix compound, 2-aminoacridine for the negative ion mode analysis and extends the selection of internal standards with m/z <1000 for both positive (15 different phosphazenium cations) and negative (anions of four fluorine-rich sulpho-compounds) ion mode. The novel internal calibration compounds and matrix material were tested for the analysis of various natural resins and real-life varnish samples taken from cultural heritage objects. Copyright © 2017 John Wiley & Sons, Ltd.
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Affiliation(s)
- A Teearu
- Institute of Chemistry, Faculty of Science and Technology, University of Tartu, Ravila 14A, Tartu, 50411, Estonia
| | - S Vahur
- Institute of Chemistry, Faculty of Science and Technology, University of Tartu, Ravila 14A, Tartu, 50411, Estonia
| | - T Rodima
- Institute of Chemistry, Faculty of Science and Technology, University of Tartu, Ravila 14A, Tartu, 50411, Estonia
| | - K Herodes
- Institute of Chemistry, Faculty of Science and Technology, University of Tartu, Ravila 14A, Tartu, 50411, Estonia
| | - W Bonrath
- DSM Nutritional Products, Research and Development, CH, 4002, Basel, Switzerland
| | - T Netscher
- DSM Nutritional Products, Research and Development, CH, 4002, Basel, Switzerland
| | - S Tshepelevitsh
- Institute of Chemistry, Faculty of Science and Technology, University of Tartu, Ravila 14A, Tartu, 50411, Estonia
| | - A Trummal
- National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, 12618, Tallinn, Estonia
| | - M Lõkov
- Institute of Chemistry, Faculty of Science and Technology, University of Tartu, Ravila 14A, Tartu, 50411, Estonia
| | - I Leito
- Institute of Chemistry, Faculty of Science and Technology, University of Tartu, Ravila 14A, Tartu, 50411, Estonia
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42
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Lõkov M, Tshepelevitsh S, Heering A, Plieger PG, Vianello R, Leito I. On the Basicity of Conjugated Nitrogen Heterocycles in Different Media. European J Org Chem 2017. [DOI: 10.1002/ejoc.201700749] [Citation(s) in RCA: 94] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Märt Lõkov
- Institute of Chemistry; University of Tartu; Ravila 14a 50411 Tartu Estonia
| | | | - Agnes Heering
- Institute of Chemistry; University of Tartu; Ravila 14a 50411 Tartu Estonia
| | - Paul G. Plieger
- Institute of Fundamental Sciences; Massey University; Private Bag 11222 Palmerston North New Zealand
| | - Robert Vianello
- Computational Organic Chemistry and Biochemistry Group; Ruđer Bošković Institute; Bijenička cesta 54 10000 Zagreb Croatia
| | - Ivo Leito
- Institute of Chemistry; University of Tartu; Ravila 14a 50411 Tartu Estonia
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43
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Jeletic MS, Hulley EB, Helm ML, Mock MT, Appel AM, Wiedner ES, Linehan JC. Understanding the Relationship Between Kinetics and Thermodynamics in CO2 Hydrogenation Catalysis. ACS Catal 2017. [DOI: 10.1021/acscatal.7b01673] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Matthew S. Jeletic
- Catalysis Science Group, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Elliott B. Hulley
- Catalysis Science Group, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Monte L. Helm
- Catalysis Science Group, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Michael T. Mock
- Catalysis Science Group, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Aaron M. Appel
- Catalysis Science Group, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Eric S. Wiedner
- Catalysis Science Group, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - John C. Linehan
- Catalysis Science Group, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
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44
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Selberg S, Rodima T, Lõkov M, Tshepelevitsh S, Haljasorg T, Chhabra S, Kadam SA, Toom L, Vahur S, Leito I. Synthesis and properties of highly lipophilic phosphazene bases. Tetrahedron Lett 2017. [DOI: 10.1016/j.tetlet.2017.04.039] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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45
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Kögel JF, Margetić D, Xie X, Finger LH, Sundermeyer J. A Phosphorus Bisylide: Exploring a New Class of Superbases with Two Interacting Carbon Atoms as Basicity Centers. Angew Chem Int Ed Engl 2017; 56:3090-3093. [DOI: 10.1002/anie.201612446] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Indexed: 11/10/2022]
Affiliation(s)
- Julius F. Kögel
- Fachbereich Chemie; Philipps-Universität Marburg; Hans-Meerwein-Strasse 35032 Marburg Germany
- FB Biologie/Chemie; Universität Bremen; Leobener Str. im NW2 28359 Bremen Germany
| | - Davor Margetić
- Ruđer Bošković Institute; Bijenička c. 54 10001 Zagreb Croatia
| | - Xiulan Xie
- Fachbereich Chemie; Philipps-Universität Marburg; Hans-Meerwein-Strasse 35032 Marburg Germany
| | - Lars H. Finger
- Fachbereich Chemie; Philipps-Universität Marburg; Hans-Meerwein-Strasse 35032 Marburg Germany
| | - Jörg Sundermeyer
- Fachbereich Chemie; Philipps-Universität Marburg; Hans-Meerwein-Strasse 35032 Marburg Germany
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46
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Kögel JF, Margetić D, Xie X, Finger LH, Sundermeyer J. Phosphorbisylid: Eine neue Klasse von Superbasen mit zwei superbasischen Kohlenstoffatomen in räumlicher Nähe. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201612446] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Julius F. Kögel
- Fachbereich Chemie; Philipps-Universität Marburg; Hans-Meerwein-Straße 35032 Marburg Deutschland
- FB Biologie/Chemie; Universität Bremen; Leobener Str. im NW2 28359 Bremen Deutschland
| | - Davor Margetić
- Ruđer Bošković Institute; Bijenička c. 54 10001 Zagreb Kroatien
| | - Xiulan Xie
- Fachbereich Chemie; Philipps-Universität Marburg; Hans-Meerwein-Straße 35032 Marburg Deutschland
| | - Lars H. Finger
- Fachbereich Chemie; Philipps-Universität Marburg; Hans-Meerwein-Straße 35032 Marburg Deutschland
| | - Jörg Sundermeyer
- Fachbereich Chemie; Philipps-Universität Marburg; Hans-Meerwein-Straße 35032 Marburg Deutschland
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47
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Kögel JF, Kovačević B, Ullrich S, Xie X, Sundermeyer J. Chelating P2-Bis-phosphazenes with a (R
,R
)-1,2-Diaminocyclohexane Skeleton: Two New Chiral Superbases. Chemistry 2017; 23:2591-2598. [DOI: 10.1002/chem.201604522] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Revised: 12/06/2016] [Indexed: 11/09/2022]
Affiliation(s)
- Julius F. Kögel
- Fachbereich Chemie; Philipps-Universität Marburg; Hans-Meerwein-Straße 35032 Marburg Germany
- Current address: FB Biologie/Chemie; Universität Bremen; Leobener Str. im NW2 28359 Bremen Germany
| | - Borislav Kovačević
- Group for Computational Life Sciences; Rudjer Bošković Institute; Bijenička c. 54 HR-10000 Zagreb Croatia
| | - Sebastian Ullrich
- Fachbereich Chemie; Philipps-Universität Marburg; Hans-Meerwein-Straße 35032 Marburg Germany
| | - Xiulan Xie
- Fachbereich Chemie; Philipps-Universität Marburg; Hans-Meerwein-Straße 35032 Marburg Germany
| | - Jörg Sundermeyer
- Fachbereich Chemie; Philipps-Universität Marburg; Hans-Meerwein-Straße 35032 Marburg Germany
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