1
|
Osenga V, Sykes NC, Pa S, Bambha MK, Schley ND, Johnson MW. Comparative Analysis of the Donor Properties of Isomeric Pyrrolyl Phosphine Ligands. Organometallics 2024; 43:14-20. [PMID: 38213984 PMCID: PMC10777409 DOI: 10.1021/acs.organomet.3c00467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Revised: 12/11/2023] [Accepted: 12/11/2023] [Indexed: 01/13/2024]
Abstract
Understanding the net donor and electronic properties of pyrrole-based phosphines is critical for guiding their use as ligands. In this study, we compare two isomeric 1- and 2-(diphenylphosphino)methylpyrroles (L1 and L2, respectively) to determine the degree to which N-(phosphino)pyrroles are distinct from aryl- and 2-pyrrolyl phosphines. Ruthenium, rhodium, platinum, and gold complexes as well as selenide derivatives of these ligands are examined using NMR and IR spectroscopy, X-ray crystallography, and cyclic voltammetry. Ligand L2 exhibits net donor properties similar to those of the o-tolyl analogue L3, while L1 shows attenuated electron donation ability. Additionally, a model nickel-catalyzed Kumada coupling reaction using these three ligands was investigated.
Collapse
Affiliation(s)
- Vicky
A. Osenga
- Department
of Chemistry, University of Richmond, Richmond, Virginia 23173, United States
| | - Nolan C. Sykes
- Department
of Chemistry, University of Richmond, Richmond, Virginia 23173, United States
| | - Sopheak Pa
- Department
of Chemistry, University of Richmond, Richmond, Virginia 23173, United States
| | - Michael K. Bambha
- Department
of Chemistry, University of Richmond, Richmond, Virginia 23173, United States
| | - Nathan D. Schley
- Department
of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, United States
| | - Miles W. Johnson
- Department
of Chemistry, University of Richmond, Richmond, Virginia 23173, United States
| |
Collapse
|
2
|
van der Westhuizen D, Castro AC, Hazari N, Gevorgyan A. Bulky, electron-rich, renewable: analogues of Beller's phosphine for cross-couplings. Catal Sci Technol 2023; 13:6733-6742. [PMID: 38026730 PMCID: PMC10680433 DOI: 10.1039/d3cy01375h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Accepted: 10/30/2023] [Indexed: 12/01/2023]
Abstract
In recent years, considerable progress has been made in the conversion of biomass into renewable chemicals, yet the range of value-added products that can be formed from biomass remains relatively small. Herein, we demonstrate that molecules available from biomass serve as viable starting materials for the synthesis of phosphine ligands, which can be used in homogeneous catalysis. Specifically, we prepared renewable analogues of Beller's ligand (di(1-adamantyl)-n-butylphosphine, cataCXium® A), which is widely used in homogeneous catalysis. Our new renewable phosphine ligands facilitate Pd-catalysed Suzuki-Miyaura, Stille, and Buchwald-Hartwig coupling reactions with high yields, and our catalytic results can be rationalized based on the stereoelectronic properties of the ligands. The new phosphine ligands generate catalytic systems that can be applied for the late-stage functionalization of commercial drugs.
Collapse
Affiliation(s)
| | - Abril C Castro
- Hylleraas Centre for Quantum Molecular Sciences, Department of Chemistry, University of Oslo 0315 Oslo Norway
| | - Nilay Hazari
- Department of Chemistry, Yale University New Haven Connecticut 06520 USA
| | - Ashot Gevorgyan
- Department of Chemistry, UiT The Arctic University of Norway 9037 Tromsø Norway
| |
Collapse
|
3
|
Schulz J, Clauss R, Kazimir A, Holzknecht S, Hey-Hawkins E. On the Edge of the Known: Extremely Electron-Rich (Di)Carboranyl Phosphines. Angew Chem Int Ed Engl 2023; 62:e202218648. [PMID: 36573025 DOI: 10.1002/anie.202218648] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Indexed: 12/28/2022]
Abstract
The syntheses of the first B9-connected carboranylphosphines (B9-Phos) featuring two carboranyl moieties as well as access to B9-Phos ligands with bulky electron-donating substituents, previously deemed unattainable, is reported. The electrochemical properties of the B9-Phos ligands were investigated, revealing the ability of the mesityl derivatives to form stabilized phosphoniumyl radical cations. The B9-Phos ligands display an extremely electron-releasing character surpassing that of alkyl phosphines and commonly used N-heterocyclic carbenes. This is demonstrated by their very small Tolman electronic parameters (TEPs) as well as extremely low P-Se coupling constants. Cone angles and buried volumes attest to the high steric demand exerted by the (di)carboranyl phosphines. The dicarboranyl phosphine AuI complexes show superior catalytic performance in the hydroamination of alkynes compared to the monocarboranyl phosphine analogs.
Collapse
Affiliation(s)
- Jan Schulz
- Leipzig University, Faculty of Chemistry and Mineralogy, Institute of Inorganic Chemistry, Johannisallee 29, 04103, Leipzig, Germany
| | - Reike Clauss
- Leipzig University, Faculty of Chemistry and Mineralogy, Institute of Inorganic Chemistry, Johannisallee 29, 04103, Leipzig, Germany
| | - Aleksandr Kazimir
- Leipzig University, Faculty of Chemistry and Mineralogy, Institute of Inorganic Chemistry, Johannisallee 29, 04103, Leipzig, Germany
| | - Sieglinde Holzknecht
- Leipzig University, Faculty of Chemistry and Mineralogy, Institute of Inorganic Chemistry, Johannisallee 29, 04103, Leipzig, Germany
| | - Evamarie Hey-Hawkins
- Leipzig University, Faculty of Chemistry and Mineralogy, Institute of Inorganic Chemistry, Johannisallee 29, 04103, Leipzig, Germany
| |
Collapse
|
4
|
Perry GL, Schley ND. Tris(bicyclo[1.1.1]pentyl)phosphine: An Exceptionally Small Tri- tert-alkylphosphine and Its Bis-Ligated Pd(0) Complex. J Am Chem Soc 2023; 145:7005-7010. [PMID: 36920072 DOI: 10.1021/jacs.3c00885] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023]
Abstract
Tris(bicyclo[1.1.1]pentyl)phosphine can be prepared by radical addition of PH3 to [1.1.1]propellane, giving the smallest tri-tert-alkylphosphine known. PBcp3 is substantially smaller than PCy3 and is comparable in electron-donating power to PEt3. It gives a bis-ligated Pd(0) complex Pd(PBcp3)2 that is exceptionally reactive toward alkyl halide oxidative addition and functions as a general ligand for palladium-catalyzed cross-coupling of sp3 electrophiles. Radical addition of [1.1.1]propellane to phenylphosphine gives the bis(bicyclo[1.1.1]pentyl)phosphine derivative PBcp2Ph, illustrating the generality of this approach to bicyclopentylphosphine synthesis.
Collapse
Affiliation(s)
- Griffin L Perry
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, United States
| | - Nathan D Schley
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, United States
| |
Collapse
|
5
|
Pattanayak S, Loewen ND, Berben LA. Using Substituted [Fe 4N(CO) 12] - as a Platform To Probe the Effect of Cation and Lewis Acid Location on Redox Potential. Inorg Chem 2023; 62:1919-1925. [PMID: 36006454 DOI: 10.1021/acs.inorgchem.2c01556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The impact of cationic and Lewis acidic functional groups installed in the primary or secondary coordination sphere (PCS or SCS) of an (electro)catalyst is known to vary depending on the precise positioning of those groups. However, it is difficult to systematically probe the effect of that position. In this report, we probe the effect of the functional group position and identity on the observed reduction potentials (Ep,c) using substituted iron clusters, [Fe4N(CO)11R]n, where R = NO+, PPh2-CH2CH2-9BBN, (MePTA+)2, (MePTA+)4, and H+ and n = 0, -1, +1, or +3 (9-BBN is 9-borabicyclo(3.3.1)nonane; MePTA+ is 1-methyl-1-azonia-3,5-diaza-7-phosphaadamantane). The cationic NO+ and H+ ligands cause anodic shifts of 700 and 320 mV, respectively, in Ep,c relative to unsubstituted [Fe4N(CO)12]-. Infrared absorption band data, νCO, suggests that some of the 700 mV shift by NO+ results from electronic changes to the cluster core. This contrasts with the effects of cationic MePTA+ and H+ which cause primarily electrostatic effects on Ep,c. Lewis acidic 9-BBN in the SCS had almost no effect on Ep,c.
Collapse
Affiliation(s)
- Santanu Pattanayak
- Department of Chemistry, University of California, Davis, California 95616, United States
| | - Natalia D Loewen
- Department of Chemistry, University of California, Davis, California 95616, United States
| | - Louise A Berben
- Department of Chemistry, University of California, Davis, California 95616, United States
| |
Collapse
|
6
|
Weberg AB, Murphy RP, Tomson NC. Oriented internal electrostatic fields: an emerging design element in coordination chemistry and catalysis. Chem Sci 2022; 13:5432-5446. [PMID: 35694353 PMCID: PMC9116365 DOI: 10.1039/d2sc01715f] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Accepted: 04/19/2022] [Indexed: 11/21/2022] Open
Abstract
The power of oriented electrostatic fields (ESFs) to influence chemical bonding and reactivity is a phenomenon of rapidly growing interest. The presence of strong ESFs has recently been implicated as one of the most significant contributors to the activity of select enzymes, wherein alignment of a substrate's changing dipole moment with a strong, local electrostatic field has been shown to be responsible for the majority of the enzymatic rate enhancement. Outside of enzymology, researchers have studied the impacts of "internal" electrostatic fields via the addition of ionic salts to reactions and the incorporation of charged functional groups into organic molecules (both experimentally and computationally), and "externally" via the implementation of bulk fields between electrode plates. Incorporation of charged moieties into homogeneous inorganic complexes to generate internal ESFs represents an area of high potential for novel catalyst design. This field has only begun to materialize within the past 10 years but could be an area of significant impact moving forward, since it provides a means for tuning the properties of molecular complexes via a method that is orthogonal to traditional strategies, thereby providing possibilities for improved catalytic conditions and novel reactivity. In this perspective, we highlight recent developments in this area and offer insights, obtained from our own research, on the challenges and future directions of this emerging field of research.
Collapse
Affiliation(s)
- Alexander B Weberg
- R, oy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania 231 S. 34th Street Philadelphia Pennsylvania 19104 USA
| | - Ryan P Murphy
- R, oy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania 231 S. 34th Street Philadelphia Pennsylvania 19104 USA
| | - Neil C Tomson
- R, oy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania 231 S. 34th Street Philadelphia Pennsylvania 19104 USA
| |
Collapse
|