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Karnbrock SBH, Golz C, Alcarazo M. P(V)-bis(amidophenolate) ligand cooperation: stoichiometric CO-bond cleavage in aldehydes and ketones. Chem Commun (Camb) 2024; 60:6745-6748. [PMID: 38864327 DOI: 10.1039/d4cc02202e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2024]
Abstract
The cooperation between a geometrically constrained, highly electrophilic phosphorus(V) center, and an electronically rich tetradentate bis(amidophenolate) ligand enables the cleavage of the CO bond from typical aldehydes and ketones delivering iminio phosphoramidate species. The amphiphilic nature of these products, which is demonstrated through their reaction with typical Lewis acids and bases, enables their use as a mild source of silylium cations from silanes, allowing the selective reductive coupling of aldehydes to ethers under catalytic conditions.
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Affiliation(s)
- Simon B H Karnbrock
- Institute of Organic and Biomolecular Chemistry, University of Göttingen, Tammannstraße 2, 37077 Göttingen, Germany.
| | - Christopher Golz
- Institute of Organic and Biomolecular Chemistry, University of Göttingen, Tammannstraße 2, 37077 Göttingen, Germany.
| | - Manuel Alcarazo
- Institute of Organic and Biomolecular Chemistry, University of Göttingen, Tammannstraße 2, 37077 Göttingen, Germany.
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2
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Hannah TJ, Chitnis SS. Ligand-enforced geometric constraints and associated reactivity in p-block compounds. Chem Soc Rev 2024; 53:764-792. [PMID: 38099873 DOI: 10.1039/d3cs00765k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2024]
Abstract
The geometry at an element centre can generally be predicted based on the number of electron pairs around it using valence shell electron pair repulsion (VSEPR) theory. Strategies to distort p-block compounds away from these predicted geometries have gained considerable interest due to the unique structural outcomes, spectroscopic properties or reactivity patterns engendered by such distortion. This review presents an up-to-date group-wise summary of this exciting and rapidly growing field with a focus on understanding how the ligand employed unlocks structural features, which in turn influences the associated reactivity. Relevant geometrically constrained compounds from groups 13-16 are discussed, along with selected stoichiometric and catalytic reactions. Several areas for advancement in this field are also discussed. Collectively, this review advances the notion of geometric tuning as an important lever, alongside electronic and steric tuning, in controlling bonding and reactivity at p-block centres.
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Affiliation(s)
- Tyler J Hannah
- Department of Chemistry, Dalhousie University, 6274 Coburg Road, Halifax, NS, B3H 4R2, Canada.
| | - Saurabh S Chitnis
- Department of Chemistry, Dalhousie University, 6274 Coburg Road, Halifax, NS, B3H 4R2, Canada.
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3
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Braese J, Lehnfeld F, Annibale VT, Oswald T, Beckhaus R, Manners I, Scheer M. Titanium-Catalyzed Polymerization of a Lewis Base-Stabilized Phosphinoborane. Chemistry 2023; 29:e202301741. [PMID: 37498679 DOI: 10.1002/chem.202301741] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 07/21/2023] [Accepted: 07/27/2023] [Indexed: 07/29/2023]
Abstract
The reaction of the Lewis base-stabilized phosphinoborane monomer tBuHPBH2 NMe3 (2 a) with catalytic amounts of bis(η5 :η1 -adamantylidenepentafulvene)titanium (1) provides a convenient new route to the polyphosphinoborane [tBuPH-BH2 ]n (3 a). This method offers access to high molar mass materials under mild conditions and with short reaction times (20 °C, 1 h in toluene). It represents an unprecedented example of a transition metal-mediated polymerization of a Lewis base-stabilized Group 13/15 compound. Preliminary studies of the substrate scope and a potential mechanism are reported.
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Affiliation(s)
- Jens Braese
- Universität Regensburg, Institut für Anorganische Chemie, 94053, Regensburg, Germany
| | - Felix Lehnfeld
- Universität Regensburg, Institut für Anorganische Chemie, 94053, Regensburg, Germany
| | - Vincent T Annibale
- University of Victoria, Department of Chemistry, 3800 Finnerty Road, Victoria, BC V8P 5C2, Canada
| | - Tim Oswald
- Carl von Ossietzky Universität Oldenburg, Institut für Chemie Carl-von-Ossietzky, Straße 9-11, 26129, Oldenburg, Germany
| | - Rüdiger Beckhaus
- Carl von Ossietzky Universität Oldenburg, Institut für Chemie Carl-von-Ossietzky, Straße 9-11, 26129, Oldenburg, Germany
| | - Ian Manners
- University of Victoria, Department of Chemistry, 3800 Finnerty Road, Victoria, BC V8P 5C2, Canada
| | - Manfred Scheer
- Universität Regensburg, Institut für Anorganische Chemie, 94053, Regensburg, Germany
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4
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Yadav R, Janßen P, Schorpp M, Greb L. Calix[4]pyrrolato-germane-(thf) 2: Unlocking the Anti-van't Hoff-Le Bel Reactivity of Germanium(IV) by Ligand Dissociation. J Am Chem Soc 2023; 145:17746-17754. [PMID: 37549106 PMCID: PMC10436272 DOI: 10.1021/jacs.3c04424] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Indexed: 08/09/2023]
Abstract
Anti-van't Hoff-Le Bel configured p-block element species possess intrinsically high reactivity and are thus challenging to isolate. Consequently, numerous elements in this configuration, including square-planar germanium(IV), remain unexplored. Herein, we follow a concept to reach anti-van't Hoff-Le Bel reactivity by ligand dissociation from a rigid calix[4]pyrrole germane in its bis(thf) adduct. While the macrocyclic ligand assures square-planar coordination in the uncomplexed form, the labile thf donors provide robustness for isolation on a multigram scale. Unique properties of a low-lying acceptor orbital imparted to germanium(IV) can be verified, e.g., by isolating an elusive anionic hydrido germanate and exploiting it for challenging bond activations. Aldehydes, water, alcohol, and a CN triple bond are activated for the first time by germanium-ligand cooperativity. Unexpected behaviors against fluoride ion donors disclose critical interferences of a putative redox-coupled fluoride ion transfer during the experimental determination of Lewis acidity. Overall, we showcase how ligand lability grants access to the uncharted chemistry of anti-van't Hoff-Le Bel germanium(IV) and line up this element as a member in the emerging class of structurally constrained p-block elements.
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Affiliation(s)
| | | | | | - Lutz Greb
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Heidelberg 69120, Germany
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5
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Moussa ME, Kahoun T, Marquardt C, Ackermann MT, Hegen O, Seidl M, Timoshkin AY, Virovets AV, Bodensteiner M, Scheer M. Three- and Five-Membered Anionic Chains of Pnictogenylboranes. Chemistry 2023; 29:e202203206. [PMID: 36478481 DOI: 10.1002/chem.202203206] [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: 10/13/2022] [Revised: 12/06/2022] [Accepted: 12/07/2022] [Indexed: 12/12/2022]
Abstract
An unprecedented family of three- and five-membered substituted anionic derivatives of parent pnictogenylboranes is herein reported. Reacting various combinations of the pnictogenylboranes H2 E'-BH2 -NMe3 (E'=P, As) with pnictogen-based nucleophiles MER1R2 (E=P, As; R1=H, R2=t Bu; R1=R2=Ph; M=Na, K) allows for the isolation of the unsymmetrical products [Na(18-crown-6)][H2 E'-BH2 -EHt Bu] (3: E=E'=P; 4: E=E'=As; 5: E=As, E'=P) and [M(C)][H2 E'-BH2 -EPh2 ] (7: E=E'=P, M=Na, C=18-crown-6; 8: E=E'=As; M=K, C=[2.2.2]cryptand; 9: E=P, E'=As, M=Na, C=[2.2.2]cryptand; 10: E=As, E'=P, M=K, C=[2.2.2]cryptand). [Na(18-crown-6)][H2 As-BH2 -t BuPH-BH3 ] (6) is only accessible by a different pathway, using t BuPH2 , BH3 ⋅ SMe2 and NaNH2 as starting materials. Additionally, the synthesis of symmetrical diphenyl-substituted compounds [M(18-crown-6)][Ph2 E-BH2 -EPh2 ] (11: E=P, M=Na; 12: E=As, M=K) is reported which can be regarded as isostructural inorganic, negatively charged analogs of dppm (1,1-bis(diphenylphosphino)methane) and dpam (1,1-bis(diphenylarsino)methane). Furthermore, an elongation of the pnictogen boron backbone in compounds 3, 7 and 9' (similar compound to 9, stabilized however by 18-crown-6), is attainable by reacting them with the pnictogenylboranes H2 E'-BH2 -NMe3 leading to corresponding five-membered chain-like compounds [Na(18-crown-6)][H2 E-BH2 -R1R2P-BH2 -E'H2 ] (E=E'=P, R1=H, R2=t Bu (13); E=E'=P, R1=R2=Ph (14); E=E'=As, R1=R2=Ph (15); E=P, E'=As, R1=R2=Ph (16)). Finally, the thermodynamics of the reaction pathways were evaluated by quantum chemical computations.
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Affiliation(s)
- Mehdi Elsayed Moussa
- Institut für Anorganische Chemie der, Universität Regensburg, 93040, Regensburg, Germany
| | - Tobias Kahoun
- Institut für Anorganische Chemie der, Universität Regensburg, 93040, Regensburg, Germany
| | - Christian Marquardt
- Institut für Anorganische Chemie der, Universität Regensburg, 93040, Regensburg, Germany
| | - Matthias T Ackermann
- Institut für Anorganische Chemie der, Universität Regensburg, 93040, Regensburg, Germany
| | - Oliver Hegen
- Institut für Anorganische Chemie der, Universität Regensburg, 93040, Regensburg, Germany
| | - Michael Seidl
- Institut für Anorganische Chemie der, Universität Regensburg, 93040, Regensburg, Germany
| | - Alexey Y Timoshkin
- Institute of Chemistry, St. Petersburg State University, Universitetskaya nab. 7/9, 199034, St. Petersburg, Russia
| | - Alexander V Virovets
- Institut für Anorganische Chemie der, Universität Regensburg, 93040, Regensburg, Germany
| | - Michael Bodensteiner
- Institut für Anorganische Chemie der, Universität Regensburg, 93040, Regensburg, Germany
| | - Manfred Scheer
- Institut für Anorganische Chemie der, Universität Regensburg, 93040, Regensburg, Germany
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6
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Race JJ, Heyam A, Wiebe MA, Diego-Garcia Hernandez J, Ellis CE, Lei S, Manners I, Weller AS. Polyphosphinoborane Block Copolymer Synthesis Using Catalytic Reversible Chain-Transfer Dehydropolymerization. Angew Chem Int Ed Engl 2023; 62:e202216106. [PMID: 36394131 PMCID: PMC10107156 DOI: 10.1002/anie.202216106] [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: 11/01/2022] [Revised: 11/15/2022] [Accepted: 11/17/2022] [Indexed: 11/19/2022]
Abstract
An amphiphilic block copolymer of polyphosphinoborane has been prepared by a mechanism-led strategy of the sequential catalytic dehydropolymerization of precursor monomers, H3 B ⋅ PRH2 (R=Ph, n-hexyl), using the simple pre-catalyst [Rh(Ph2 PCH2 CH2 PPh2 )2 ]Cl. Speciation, mechanism and polymer chain growth studies support a step-growth process where reversible chain transfer occurs, i.e. H3 B ⋅ PRH2 /oligomer/polymer can all coordinate with, and be activated by, the catalyst. Block copolymer [H2 BPPhH]110 -b-[H2 BP(n-hexyl)H]11 can be synthesized and self-assembles in solution to form either rod-like micelles or vesicles depending on solvent polarity.
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Affiliation(s)
- James J Race
- Department of Chemistry, University of York, Heslington, York, YO10 5DD, UK.,Chemistry Research Laboratories, University of Oxford, Oxford, OX1 3TA, UK
| | - Alex Heyam
- Department of Chemistry, University of York, Heslington, York, YO10 5DD, UK
| | - Matthew A Wiebe
- Department of Chemistry, University of Victoria, Victoria, BC, V8P 5C2, Canada
| | | | - Charlotte E Ellis
- Department of Chemistry, University of Victoria, Victoria, BC, V8P 5C2, Canada
| | - Shixing Lei
- Department of Chemistry, University of Victoria, Victoria, BC, V8P 5C2, Canada
| | - Ian Manners
- Department of Chemistry, University of Victoria, Victoria, BC, V8P 5C2, Canada.,Centre for Advanced Materials and Related Technology (CAMTEC), University of Victoria, Victoria, BC, V8P 5C2, Canada
| | - Andrew S Weller
- Department of Chemistry, University of York, Heslington, York, YO10 5DD, UK
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7
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Wiebe MA, Kundu S, LaPierre EA, Patrick BO, Manners I. Transition-Metal-Free Dehydropolymerization of Phosphine-Boranes at Ambient Temperature. Chemistry 2023; 29:e202202897. [PMID: 36196020 DOI: 10.1002/chem.202202897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Indexed: 11/16/2022]
Abstract
Stoichiometric reaction of phosphine-borane adducts RR'PH⋅BH3 (R=Ph, R'=H, Ph, Et, and R=R'=t Bu) with the strong acid HNTf2 (Tf=SO2 CF3 ) leads to H2 elimination and the formation of the triflimido derivatives, RR'PH⋅BH2 (NTf2 ). Subsequent deprotonation by using bases, such as diisopropylethylamine or the carbene IPr (IPr=N,N'-bis(2,6-diisopropylphenyl)imidazol-2-ylidene), led to the formation of P-mono- or -disubstituted polyphosphinoboranes [RR'P-BH2 ]n . Evidence for the intermediacy of transient phosphinoborane monomers, RR'PBH2 , was provided by trapping reactions.
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Affiliation(s)
- Matthew A Wiebe
- Department of Chemistry, University of Victoria, 3800 Finnerty Rd, Victoria, British Columbia, V8P 5 C2, Canada
| | - Subrata Kundu
- Department of Chemistry, University of Victoria, 3800 Finnerty Rd, Victoria, British Columbia, V8P 5 C2, Canada.,Department of Chemistry, Indian Institute of Technology Delhi Hauz Khas, New Delhi, 110016, India
| | - Etienne A LaPierre
- Department of Chemistry, University of Victoria, 3800 Finnerty Rd, Victoria, British Columbia, V8P 5 C2, Canada
| | - Brian O Patrick
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia, V6T 1Z1, Canada
| | - Ian Manners
- Department of Chemistry, University of Victoria, 3800 Finnerty Rd, Victoria, British Columbia, V8P 5 C2, Canada
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8
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Rather IA, Ali R, Ali A. Recent developments in calix[4]pyrrole (C4P)-based supramolecular functional systems. Org Chem Front 2022. [DOI: 10.1039/d2qo01298g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Recent advances with calix[4]pyrrole-based supramolecular functional entities in the fields of molecular recognition (receptors, sensors, and metal ion caged systems), self-assembly (polymers), photo/pH-responsive molecular switches and catalysis are reviewed.
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Affiliation(s)
- Ishfaq Ahmad Rather
- Organic and Supramolecular Functional Materials Research Laboratory, Department of Chemistry, Jamia Millia Islamia, Jamia Nagar, Okhla, New Delhi-110025, India
| | - Rashid Ali
- Organic and Supramolecular Functional Materials Research Laboratory, Department of Chemistry, Jamia Millia Islamia, Jamia Nagar, Okhla, New Delhi-110025, India
| | - Ayaaz Ali
- Organic and Supramolecular Functional Materials Research Laboratory, Department of Chemistry, Jamia Millia Islamia, Jamia Nagar, Okhla, New Delhi-110025, India
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