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Gonçalves YG, Becceneri AB, Graminha AE, Miranda VM, Rios RR, Rinaldi-Neto F, Costa MS, Gonçalves ACR, Deflon VM, Yoneyama KAG, Maia PIS, Franca EF, Cominetti MR, Silva RS, Von Poelhsitz G. New ruthenium(II) complexes with cyclic thio- and semicarbazone: evaluation of cytotoxicity and effects on cell migration and apoptosis of lung cancer cells. Dalton Trans 2023. [PMID: 37377063 DOI: 10.1039/d3dt00750b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/29/2023]
Abstract
We describe the synthesis, physicochemical characterization, and in vitro antitumor assays of four novel analogous ruthenium(II) complexes with general formula cis-[RuII(N-L)(P-P)2]PF6, where P-P = bis(diphenylphosphine)methane (dppm, in complexes 1 and 2) or bis(diphenylphosphine)ethane (dppe, in complexes 3 and 4) and N-L = 5,6-diphenyl-4,5-dihydro-2H-[1,2,4]triazine-3-thione (Btsc, in complexes 1 and 3) or 5,6-diphenyltriazine-3-one (Bsc, in complexes 2 and 4). The data were consistent with cis arrangement of the biphosphine ligands. For the Btsc and Bsc ligands, the data pointed to monoanionic bidentate coordination to ruthenium(II) through N,S and N,O, respectively. Single-crystal X-ray diffraction showed that complex 1 crystallized in the monoclinic system, space group P21/c. Determination of the cytotoxicity profiles of complexes 1-4 gave SI values ranging from 1.19 to 3.50 against the human lung adenocarcinoma cell line A549 and the non-tumor lung cell line MRC-5. Although the molecular docking studies suggested that the interaction between DNA and complex 4 was energetically favorable, the experimental results showed that they interacted weakly. Overall, our results demonstrated that these novel ruthenium(II) complexes have interesting in vitro antitumor potential and this study may contribute to further studies in medicinal inorganic chemistry.
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Affiliation(s)
- Yasmim G Gonçalves
- Chemistry Institute, Federal University of Uberlândia, Uberlândia, MG, Brazil.
- Laboratório de Fotoquímica e Química Bioinorgânica, School of Pharmaceutical Sciences, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Amanda B Becceneri
- Laboratório de Fotoquímica e Química Bioinorgânica, School of Pharmaceutical Sciences, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Angelica E Graminha
- Laboratório de Fotoquímica e Química Bioinorgânica, School of Pharmaceutical Sciences, University of São Paulo, Ribeirão Preto, SP, Brazil
- Gerontology Department, Federal University of São Carlos, São Carlos, SP, Brazil
| | - Victor M Miranda
- Grupo de Química Inorgânica Estrutural e Biológica, Chemistry Institute of São Carlos, Universidade de São Paulo, USP - São Carlos, São Carlos, SP, Brazil
| | - Rafaella R Rios
- Laboratório de Fotoquímica e Química Bioinorgânica, School of Pharmaceutical Sciences, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Francisco Rinaldi-Neto
- Laboratório de Fotoquímica e Química Bioinorgânica, School of Pharmaceutical Sciences, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Mônica S Costa
- Genetic and Biochemistry Institute, Federal University of Uberlândia, Uberlândia, MG, Brazil
| | - Ana C R Gonçalves
- Exacts, Natural Sciences, and Education Institute, Federal University of Triângulo Mineiro, Uberaba, MG, Brazil
| | - Victor M Deflon
- Laboratório de Fotoquímica e Química Bioinorgânica, School of Pharmaceutical Sciences, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Kelly A G Yoneyama
- Genetic and Biochemistry Institute, Federal University of Uberlândia, Uberlândia, MG, Brazil
| | - Pedro I S Maia
- Exacts, Natural Sciences, and Education Institute, Federal University of Triângulo Mineiro, Uberaba, MG, Brazil
| | - Eduardo F Franca
- Laboratório de Cristalografia e Química Computacional, Chemistry Institute, Federal University of Uberlândia, Uberlândia, MG, Brazil
| | - Márcia R Cominetti
- Gerontology Department, Federal University of São Carlos, São Carlos, SP, Brazil
| | - Roberto S Silva
- Laboratório de Fotoquímica e Química Bioinorgânica, School of Pharmaceutical Sciences, University of São Paulo, Ribeirão Preto, SP, Brazil
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2
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Khoo S, Siu CK, So CW. A Base-Stabilized Silylene-Promoted C(sp3)–H Borylation and H2 Activation. Inorg Chem 2020; 59:9551-9559. [DOI: 10.1021/acs.inorgchem.0c00426] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Sabrina Khoo
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371
| | - Chi-Kit Siu
- Department of Chemistry, City University of Hong Kong, Hong Kong SAR, China
| | - Cheuk-Wai So
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371
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3
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Spearing-Ewyn EAK, Beattie NA, Colebatch AL, Martinez-Martinez AJ, Docker A, Boyd TM, Baillie G, Reed R, Macgregor SA, Weller AS. The role of neutral Rh(PONOP)H, free NMe 2H, boronium and ammonium salts in the dehydrocoupling of dimethylamine-borane using the cationic pincer [Rh(PONOP)(η 2-H 2)] + catalyst. Dalton Trans 2019; 48:14724-14736. [PMID: 31538996 DOI: 10.1039/c9dt03358k] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The σ-amine-borane pincer complex [Rh(PONOP)(η1-H3B·NMe3)][BArF4] [2, PONOP = κ3-NC5H3-2,6-(OPtBu2)2] is prepared by addition of H3B·NMe3 to the dihydrogen precursor [Rh(PONOP)(η2-H2)][BArF4], 1. In a similar way the related H3B·NMe2H complex [Rh(PONOP)(η1-H3B·NMe2H)][BArF4], 3, can be made in situ, but this undergoes dehydrocoupling to reform 1 and give the aminoborane dimer [H2BNMe2]2. NMR studies on this system reveal an intermediate neutral hydride forms, Rh(PONOP)H, 4, that has been prepared independently. 1 is a competent catalyst (2 mol%, ∼30 min) for the dehydrocoupling of H3B·Me2H. Kinetic, mechanistic and computational studies point to the role of NMe2H in both forming the neutral hydride, via deprotonation of a σ-amine-borane complex and formation of aminoborane, and closing the catalytic cycle by reprotonation of the hydride by the thus-formed dimethyl ammonium [NMe2H2]+. Competitive processes involving the generation of boronium [H2B(NMe2H)2]+ are also discussed, but shown to be higher in energy. Off-cycle adducts between [NMe2H2]+ or [H2B(NMe2H)2]+ and amine-boranes are also discussed that act to modify the kinetics of dehydrocoupling.
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4
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Adams GM, Ryan DE, Beattie NA, McKay AI, Lloyd-Jones GC, Weller AS. Dehydropolymerization of H 3B·NMeH 2 Using a [Rh(DPEphos)] + Catalyst: The Promoting Effect of NMeH 2. ACS Catal 2019; 9:3657-3666. [PMID: 30984472 PMCID: PMC6454579 DOI: 10.1021/acscatal.9b00081] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 03/02/2019] [Indexed: 01/01/2023]
Abstract
![]()
[Rh(κ2-PP-DPEphos){η2η2-H2B(NMe3)(CH2)2tBu}][BArF4]
acts as an effective precatalyst
for the dehydropolymerization of H3B·NMeH2 to form N-methylpolyaminoborane (H2BNMeH)n. Control of polymer molecular weight is
achieved by variation of precatalyst loading (0.1–1 mol %,
an inverse relationship) and use of the chain-modifying agent H2: with Mn ranging between 5 500
and 34 900 g/mol and Đ between 1.5 and
1.8. H2 evolution studies (1,2-F2C6H4 solvent) reveal an induction period that gets longer
with higher precatalyst loading and complex kinetics with a noninteger
order in [Rh]TOTAL. Speciation studies at 10 mol % indicate
the initial formation of the amino–borane bridged dimer, [Rh2(κ2-PP-DPEphos)2(μ-H)(μ-H2BN=HMe)][BArF4], followed by the crystallographically
characterized amidodiboryl complex [Rh2(cis-κ2-PP-DPEphos)2(σ,μ-(H2B)2NHMe)][BArF4]. Adding
∼2 equiv of NMeH2 in tetrahydrofuran (THF) solution
to the precatalyst removes this induction period, pseudo-first-order
kinetics are observed, a half-order relationship to [Rh]TOTAL is revealed with regard to dehydrogenation, and polymer molecular
weights are increased (e.g., Mn = 40 000
g/mol). Speciation studies suggest that NMeH2 acts to form
the precatalysts [Rh(κ2-DPEphos)(NMeH2)2][BArF4] and [Rh(κ2-DPEphos)(H)2(NMeH2)2][BArF4], which were independently synthesized and shown to
follow very similar dehydrogenation kinetics, and produce polymers
of molecular weight comparable with [Rh(κ2-PP-DPEphos){η2-H2B(NMe3)(CH2)2tBu}][BArF4], which has been doped
with amine. This promoting effect of added amine in situ is shown
to be general in other cationic Rh-based systems, and possible mechanistic
scenarios are discussed.
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Affiliation(s)
- Gemma M. Adams
- Chemistry Research Laboratories, Mansfield Road, University of Oxford, Oxford OX1 3TA, United Kingdom
| | - David E. Ryan
- Chemistry Research Laboratories, Mansfield Road, University of Oxford, Oxford OX1 3TA, United Kingdom
| | - Nicholas A. Beattie
- Institute of Chemical Sciences, Heriot Watt University, Edinburgh EH14 4AS, United Kingdom
| | - Alasdair I. McKay
- Chemistry Research Laboratories, Mansfield Road, University of Oxford, Oxford OX1 3TA, United Kingdom
| | - Guy C. Lloyd-Jones
- School of Chemistry, University of Edinburgh, Edinburgh EH9 3FJ, United Kingdom
| | - Andrew S. Weller
- Chemistry Research Laboratories, Mansfield Road, University of Oxford, Oxford OX1 3TA, United Kingdom
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5
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Han D, Anke F, Trose M, Beweries T. Recent advances in transition metal catalysed dehydropolymerisation of amine boranes and phosphine boranes. Coord Chem Rev 2019. [DOI: 10.1016/j.ccr.2018.09.016] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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6
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Cowie BE, Emslie DJH. Reactivity of a Borane-Appended 1,1′-Bisphosphinoferrocene Ligand: Transition Metal and Lewis Acid Coordination, Cyclopentadienyl Ring Borylation, and Boronium Cation Generation. Organometallics 2018. [DOI: 10.1021/acs.organomet.8b00021] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Bradley E. Cowie
- Department of Chemistry and Chemical Biology, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4M1, Canada
| | - David J. H. Emslie
- Department of Chemistry and Chemical Biology, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4M1, Canada
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7
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Vondung L, Sattler LE, Langer R. Ambireactive (R3
P)2
BH2
Groups Facilitating Temperature-Switchable Bond Activation by an Iron Complex. Chemistry 2017; 24:1358-1364. [DOI: 10.1002/chem.201704018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Indexed: 12/20/2022]
Affiliation(s)
- Lisa Vondung
- Department of Chemistry; Philipps-Universität Marburg; Hans-Meerwein-Str. 4 35032 Marburg Germany
| | - Lars E. Sattler
- Department of Chemistry; Philipps-Universität Marburg; Hans-Meerwein-Str. 4 35032 Marburg Germany
| | - Robert Langer
- Department of Chemistry; Philipps-Universität Marburg; Hans-Meerwein-Str. 4 35032 Marburg Germany
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8
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Braunschweig H, Brückner T, Deißenberger A, Dewhurst RD, Gackstatter A, Gärtner A, Hofmann A, Kupfer T, Prieschl D, Thiess T, Wang SR. Reaction of Dihalodiboranes(4) with a N‐Heterocyclic Silylene: Facile Construction of 1‐Aryl‐2‐Silyl‐1,2‐Diboraindanes. Chemistry 2017; 23:9491-9494. [DOI: 10.1002/chem.201702377] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Indexed: 12/23/2022]
Affiliation(s)
- Holger Braunschweig
- Institut für Anorganische ChemieJulius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
- Institute for Sustainable Chemistry and Catalysis with BoronJulius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Tobias Brückner
- Institut für Anorganische ChemieJulius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
- Institute for Sustainable Chemistry and Catalysis with BoronJulius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Andrea Deißenberger
- Institut für Anorganische ChemieJulius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
- Institute for Sustainable Chemistry and Catalysis with BoronJulius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Rian D. Dewhurst
- Institut für Anorganische ChemieJulius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
- Institute for Sustainable Chemistry and Catalysis with BoronJulius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Annika Gackstatter
- Institut für Anorganische ChemieJulius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
- Institute for Sustainable Chemistry and Catalysis with BoronJulius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Annalena Gärtner
- Institut für Anorganische ChemieJulius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
- Institute for Sustainable Chemistry and Catalysis with BoronJulius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Alexander Hofmann
- Institut für Anorganische ChemieJulius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
- Institute for Sustainable Chemistry and Catalysis with BoronJulius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Thomas Kupfer
- Institut für Anorganische ChemieJulius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
- Institute for Sustainable Chemistry and Catalysis with BoronJulius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Dominic Prieschl
- Institut für Anorganische ChemieJulius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
- Institute for Sustainable Chemistry and Catalysis with BoronJulius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Torsten Thiess
- Institut für Anorganische ChemieJulius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
- Institute for Sustainable Chemistry and Catalysis with BoronJulius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Sunewang Rixin Wang
- Institut für Anorganische ChemieJulius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
- Institute for Sustainable Chemistry and Catalysis with BoronJulius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
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9
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Hill AF, Ward JS. Synthetic and structural studies of phosphine coordinated boronium salts. Dalton Trans 2017; 46:7291-7308. [PMID: 28540968 DOI: 10.1039/c7dt01023k] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The reaction of BrH2B·SMe2 with primary and secondary phosphines affords a range of boronium salts of the form [H2B(PR3)2]Br (PR3 = PHCy21; PHPh2, 2; PH2Cy, 3), which have been fully characterised including solid-state determinations. Reactions of bulky tertiary phosphines, e.g., PCy3 and PPh3, with BrH2B·SMe2 do not proceed beyond the phosphine-stabilised bromoborane adducts, however, the smaller tertiary phosphine PMe2Ph readily proceeds to form [H2B(PMe2Ph)2]Br (4). The formation of the unsymmetrical boronium salts [H2B(PH2Cy)(PHCy2)]Br (5) and [H2B(PHCy2)(PHPh2)]Br (6) was observed by in situ NMR spectroscopy, however, the compounds were found to spontaneously disproportionate to their respective homophosphine boronium cations, even on prolonged storage in solution at -78 °C. Di- and triphosphines were found to form ring-closed boronium salts to afford [H2B(κ2-P,P'-diphosphine)]Br (diphosphine = dppe, 7; dcpe, 8; dmpe, 9; dppf, 10; dppf with [AsF6]- counterion, 11; amphos, 12). The analogous methodology with Br2HB·SMe2 proved less generally applicable due to an accessible decomposition pathway being available to boronium salts bearing primary and secondary phosphines, leading to the formation of phosphonium salts, although [BrHB(dcpe)]Br (13), [BrHB(PMe2Ph)2]Br (14) and [BrHB(amphos)]Br (15) were synthesised with varying degrees of success. Reaction of BrH2B·SMe2 with diphars afforded the boronium salt [H2B(κ2-P,P'-diphars)]Br (16), which featured two pendant arsine arms. Similarly, triphos was found to react with BrH2B·SMe2 to give [H2B(κ2-P,P'-triphos)]Br (17), which featured a pendant phosphine arm. Substitution of the bromide counter anion with either hexafluoroarsenate or hexfluoroantimonate anions revealed weak hydrogen bonds between the P-H bonds of the boronium cations and the anions, that appeared through NMR studies to be retained in solution (where hydrogen bonding order was determined to be Br- > [SbF6]-/[AsF6]-). This was further demonstrated by comparison of solid-state structures and solution NMR data of 1 with [H2B(PHCy2)2][SbF6] (18), 4 with [H2B(PMe2Ph)2][AsF6] (19) and 17 with [H2B(triphos)][AsF6] (20).
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Affiliation(s)
- Anthony F Hill
- Research School of Chemistry, The Australian National University, Canberra, ACT 2601, Australia.
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10
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Tagne Kuate AC, Lalancette RA, Jäkle F. Planar-chiral ferrocenylphosphine-borane complexes featuring agostic-type B–H⋯E (E = Hg, Sn) interactions. Dalton Trans 2017; 46:6253-6264. [DOI: 10.1039/c6dt04791b] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Ferrocenylphosphine-borane adducts with Lewis acidic organotin and organomercury substituents inortho-position show rare agostic-type B–H⋯E (E = Sn, Hg) interactions that have been studied by single crystal XRD, multinuclear solution NMR, and computational methods.
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Affiliation(s)
- Alain C. Tagne Kuate
- Department of Chemistry
- Rutgers University-Newark
- Newark
- USA
- Department of Chemistry
| | | | - F. Jäkle
- Department of Chemistry
- Rutgers University-Newark
- Newark
- USA
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11
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Grätz M, Bäcker A, Vondung L, Maser L, Reincke A, Langer R. Donor ligands based on tricoordinate boron formed by B–H-activation of bis(phosphine)boronium salts. Chem Commun (Camb) 2017; 53:7230-7233. [DOI: 10.1039/c7cc02335a] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The (R3P)2HB-moiety in a palladium(ii) pincer complex is demonstrated to be a L-type ligand and compared with other bonding types.
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Affiliation(s)
- Maik Grätz
- Department of Chemistry
- Philipps-Universität Marburg
- 35032 Marburg
- Germany
| | - Andreas Bäcker
- Department of Chemistry
- Philipps-Universität Marburg
- 35032 Marburg
- Germany
| | - Lisa Vondung
- Department of Chemistry
- Philipps-Universität Marburg
- 35032 Marburg
- Germany
| | - Leon Maser
- Department of Chemistry
- Philipps-Universität Marburg
- 35032 Marburg
- Germany
| | - Arian Reincke
- Department of Chemistry
- Philipps-Universität Marburg
- 35032 Marburg
- Germany
| | - Robert Langer
- Department of Chemistry
- Philipps-Universität Marburg
- 35032 Marburg
- Germany
- Lehn Institute of Functional Material (LIFM)
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12
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Kumar A, Beattie NA, Pike SD, Macgregor SA, Weller AS. The Simplest Amino-borane H2 B=NH2 Trapped on a Rhodium Dimer: Pre-Catalysts for Amine-Borane Dehydropolymerization. Angew Chem Int Ed Engl 2016; 55:6651-6. [PMID: 27100775 PMCID: PMC5074255 DOI: 10.1002/anie.201600898] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Revised: 03/22/2016] [Indexed: 11/17/2022]
Abstract
The μ-amino-borane complexes [Rh2 (L(R) )2 (μ-H)(μ-H2 B=NHR')][BAr(F) 4 ] (L(R) =R2 P(CH2 )3 PR2 ; R=Ph, (i) Pr; R'=H, Me) form by addition of H3 B⋅NMeR'H2 to [Rh(L(R) )(η(6) -C6 H5 F)][BAr(F) 4 ]. DFT calculations demonstrate that the amino-borane interacts with the Rh centers through strong Rh-H and Rh-B interactions. Mechanistic investigations show that these dimers can form by a boronium-mediated route, and are pre-catalysts for amine-borane dehydropolymerization, suggesting a possible role for bimetallic motifs in catalysis.
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Affiliation(s)
- Amit Kumar
- Department of Chemistry, Chemistry Research Laboratories, University of Oxford, Mansfield Road, Oxford, OX1 3TA, UK
| | - Nicholas A Beattie
- Institute of Chemical Sciences, Heriot Watt University, Edinburgh, EH14 4AS, UK
| | - Sebastian D Pike
- Department of Chemistry, Chemistry Research Laboratories, University of Oxford, Mansfield Road, Oxford, OX1 3TA, UK
| | - Stuart A Macgregor
- Institute of Chemical Sciences, Heriot Watt University, Edinburgh, EH14 4AS, UK.
| | - Andrew S Weller
- Department of Chemistry, Chemistry Research Laboratories, University of Oxford, Mansfield Road, Oxford, OX1 3TA, UK.
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13
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Kumar A, Beattie NA, Pike SD, Macgregor SA, Weller AS. The Simplest Amino-borane H2B=NH2Trapped on a Rhodium Dimer: Pre-Catalysts for Amine-Borane Dehydropolymerization. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201600898] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Amit Kumar
- Department of Chemistry, Chemistry Research Laboratories; University of Oxford; Mansfield Road Oxford OX1 3TA UK
| | - Nicholas A. Beattie
- Institute of Chemical Sciences; Heriot Watt University; Edinburgh EH14 4AS UK
| | - Sebastian D. Pike
- Department of Chemistry, Chemistry Research Laboratories; University of Oxford; Mansfield Road Oxford OX1 3TA UK
| | - Stuart A. Macgregor
- Institute of Chemical Sciences; Heriot Watt University; Edinburgh EH14 4AS UK
| | - Andrew S. Weller
- Department of Chemistry, Chemistry Research Laboratories; University of Oxford; Mansfield Road Oxford OX1 3TA UK
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14
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Engesser TA, Lichtenthaler MR, Schleep M, Krossing I. Reactive p-block cations stabilized by weakly coordinating anions. Chem Soc Rev 2016; 45:789-899. [PMID: 26612538 PMCID: PMC4758321 DOI: 10.1039/c5cs00672d] [Citation(s) in RCA: 222] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Indexed: 12/12/2022]
Abstract
The chemistry of the p-block elements is a huge playground for fundamental and applied work. With their bonding from electron deficient to hypercoordinate and formally hypervalent, the p-block elements represent an area to find terra incognita. Often, the formation of cations that contain p-block elements as central ingredient is desired, for example to make a compound more Lewis acidic for an application or simply to prove an idea. This review has collected the reactive p-block cations (rPBC) with a comprehensive focus on those that have been published since the year 2000, but including the milestones and key citations of earlier work. We include an overview on the weakly coordinating anions (WCAs) used to stabilize the rPBC and give an overview to WCA selection, ionization strategies for rPBC-formation and finally list the rPBC ordered in their respective group from 13 to 18. However, typical, often more organic ion classes that constitute for example ionic liquids (imidazolium, ammonium, etc.) were omitted, as were those that do not fulfill the - naturally subjective -"reactive"-criterion of the rPBC. As a rule, we only included rPBC with crystal structure and only rarely refer to important cations published without crystal structure. This collection is intended for those who are simply interested what has been done or what is possible, as well as those who seek advice on preparative issues, up to people having a certain application in mind, where the knowledge on the existence of a rPBC that might play a role as an intermediate or active center may be useful.
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Affiliation(s)
- Tobias A. Engesser
- Institut für Anorganische und Analytische Chemie and Freiburger Materialforschungszentrum (FMF) , Universität Freiburg , Albertstr. 21 , 79104 Freiburg , Germany .
| | - Martin R. Lichtenthaler
- Institut für Anorganische und Analytische Chemie and Freiburger Materialforschungszentrum (FMF) , Universität Freiburg , Albertstr. 21 , 79104 Freiburg , Germany .
| | - Mario Schleep
- Institut für Anorganische und Analytische Chemie and Freiburger Materialforschungszentrum (FMF) , Universität Freiburg , Albertstr. 21 , 79104 Freiburg , Germany .
| | - Ingo Krossing
- Institut für Anorganische und Analytische Chemie and Freiburger Materialforschungszentrum (FMF) , Universität Freiburg , Albertstr. 21 , 79104 Freiburg , Germany .
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Hooper TN, Weller AS, Beattie NA, Macgregor SA. Dehydrocoupling of phosphine-boranes using the [RhCp*Me(PMe 3)(CH 2Cl 2)][BAr F4] precatalyst: stoichiometric and catalytic studies. Chem Sci 2015; 7:2414-2426. [PMID: 29997783 PMCID: PMC6003611 DOI: 10.1039/c5sc04150c] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Accepted: 12/19/2015] [Indexed: 01/08/2023] Open
Abstract
Detailed experimental and computational studies are reported on the fundamental B–H and P–H bond activation steps involved in the dehydrocoupling/dehydropolymerization of primary and secondary phosphine–boranes, H3B·PPhR′H (R = Ph, H), using the [RhCp*(PMe3)Me(ClCH2Cl)][BArF4] catalyst.
We report a detailed, combined experimental and computational study on the fundamental B–H and P–H bond activation steps involved in the dehydrocoupling/dehydropolymerization of primary and secondary phosphine–boranes, H3B·PPhR′H (R = Ph, H), using [RhCp*(PMe3)Me(ClCH2Cl)][BArF4], to either form polyphosphino-boranes [H2B·PPhH]n (Mn ∼ 15 000 g mol–1, PDI = 2.2) or the linear diboraphosphine H3B·PPh2BH2·PPh2H. A likely polymer-growth pathway of reversible chain transfer step-growth is suggested for H3B·PPhH2. Using secondary phosphine–boranes as model substrates a combined synthesis, structural (X-ray crystallography), labelling and computational approach reveals: initial bond activation pathways (B–H activation precedes P–H activation); key intermediates (phosphido-boranes, α-B-agostic base-stabilized boryls); and a catalytic route to the primary diboraphosphine (H3B·PPhHBH2·PPhH2). It is also shown that by changing the substituent at phosphorus (Ph or Cy versustBu) different final products result (phosphido-borane or base stabilized phosphino-borane respectively). These studies provide detailed insight into the pathways that are operating during dehydropolymerization.
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Affiliation(s)
- Thomas N Hooper
- Department of Chemistry , Chemistry Research Laboratories , University of Oxford , Mansfield Road , Oxford , OX1 3TA , UK .
| | - Andrew S Weller
- Department of Chemistry , Chemistry Research Laboratories , University of Oxford , Mansfield Road , Oxford , OX1 3TA , UK .
| | - Nicholas A Beattie
- Institute of Chemical Sciences , Heriot Watt University , Edinburgh , EH14 4AS , UK .
| | - Stuart A Macgregor
- Institute of Chemical Sciences , Heriot Watt University , Edinburgh , EH14 4AS , UK .
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Hooper TN, Huertos MA, Jurca T, Pike SD, Weller AS, Manners I. Effect of the phosphine steric and electronic profile on the Rh-promoted dehydrocoupling of phosphine-boranes. Inorg Chem 2014; 53:3716-29. [PMID: 24617924 PMCID: PMC3979130 DOI: 10.1021/ic500032f] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
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The electronic and
steric effects in the stoichiometric dehydrocoupling
of secondary and primary phosphine–boranes H3B·PR2H [R = 3,5-(CF3)2C6H3; p-(CF3)C6H4; p-(OMe)C6H4; adamantyl,
Ad] and H3B·PCyH2 to form the metal-bound
linear diboraphosphines H3B·PR2BH2·PR2H and H3B·PRHBH2·PRH2, respectively, are reported. Reaction of [Rh(L)(η6-FC6H5)][BArF4] [L = Ph2P(CH2)3PPh2, ArF = 3,5-(CF3)2C6H3] with 2 equiv of H3B·PR2H affords
[Rh(L)(H)(σ,η-PR2BH3)(η1-H3B·PR2H)][BArF4]. These complexes undergo dehydrocoupling to give the diboraphosphine
complexes [Rh(L)(H)(σ,η2-PR2·BH2PR2·BH3)][BArF4]. With electron-withdrawing groups on the phosphine–borane there is the parallel formation
of the products of B–P cleavage, [Rh(L)(PR2H)2][BArF4], while with electron-donating
groups no parallel product is formed. For the bulky, electron rich,
H3B·P(Ad)2H no dehydrocoupling is observed,
but an intermediate Rh(I) σ phosphine–borane complex
is formed, [Rh(L){η2-H3B·P(Ad)2H}][BArF4], that undergoes B–P
bond cleavage to give [Rh(L){η1-H3B·P(Ad)2H}{P(Ad)2H}][BArF4]. The
relative rates of dehydrocoupling of H3B·PR2H (R = aryl) show that increasingly electron-withdrawing substituents
result in faster dehydrocoupling, but also suffer from the formation
of the parallel product resulting from P–B bond cleavage. H3B·PCyH2 undergoes a similar dehydrocoupling
process, and gives a mixture of stereoisomers of the resulting metal-bound
diboraphosphine that arise from activation of the prochiral P–H
bonds, with one stereoisomer favored. This diastereomeric mixture
may also be biased by use of a chiral phosphine ligand. The selectivity
and efficiencies of resulting catalytic dehydrocoupling processes
are also briefly discussed. The effect of changing the steric and
electronic profile
of the phosphine of primary and secondary phosphine−boranes
H3B·PR2H (R = H, aryl, adamantyl) on the
Rh-catalyzed dehydrocoupling to form metal-bound linear diboraphosphines
is reported.
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Affiliation(s)
- Thomas N Hooper
- Department of Chemistry, University of Oxford , Mansfield Road, Oxford OX1 3TA, United Kingdom
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