1
|
Stachulski AV, Rossignol JF, Pate S, Taujanskas J, Iggo JA, Aerts R, Pascal E, Piacentini S, La Frazia S, Santoro MG, van Vooren L, Sintubin L, Cooper M, Swift K, O’Neill PM. Thiazolide Prodrug Esters and Derived Peptides: Synthesis and Activity. ACS Bio Med Chem Au 2023; 3:327-334. [PMID: 37599793 PMCID: PMC10436260 DOI: 10.1021/acsbiomedchemau.2c00083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 03/23/2023] [Accepted: 03/24/2023] [Indexed: 08/22/2023]
Abstract
Amino acid ester prodrugs of the thiazolides, introduced to improve the pharmacokinetic parameters of the parent drugs, proved to be stable as their salts but were unstable at pH > 5. Although some of the instability was due to simple hydrolysis, we have found that the main end products of the degradation were peptides formed by rearrangement. These peptides were stable solids: they maintained significant antiviral activity, and in general, they showed improved pharmacokinetics (better solubility and reduced clearance) compared to the parent thiazolides. We describe the preparation and evaluation of these peptides.
Collapse
Affiliation(s)
- Andrew V. Stachulski
- Donnan
and Robert Robinson Laboratories, Department of Chemistry, University of Liverpool, Liverpool L69 7ZD, U.K.
| | | | - Sophie Pate
- Donnan
and Robert Robinson Laboratories, Department of Chemistry, University of Liverpool, Liverpool L69 7ZD, U.K.
| | - Joshua Taujanskas
- Donnan
and Robert Robinson Laboratories, Department of Chemistry, University of Liverpool, Liverpool L69 7ZD, U.K.
| | - Jonathan A. Iggo
- Donnan
and Robert Robinson Laboratories, Department of Chemistry, University of Liverpool, Liverpool L69 7ZD, U.K.
| | - Rudi Aerts
- Romark
Belgium BVBA, Roosveld
6, 3400 Landen, Belgium
| | | | - Sara Piacentini
- Department
of Biology, University of Rome Tor Vergata, 00133 Rome, Italy
| | - Simone La Frazia
- Department
of Biology, University of Rome Tor Vergata, 00133 Rome, Italy
| | - M. Gabriella Santoro
- Department
of Biology, University of Rome Tor Vergata, 00133 Rome, Italy
- Institute
of Translational Pharmacology, CNR, Area della Ricerca di Roma 2, Via Fosso del Cavaliere, 00133 Roma, Italy
| | | | | | - Mark Cooper
- Bio-Techne, Avonmouth, Bristol BS11 9QD, U.K.
| | - Karl Swift
- Bio-Techne, Avonmouth, Bristol BS11 9QD, U.K.
| | - Paul M. O’Neill
- Donnan
and Robert Robinson Laboratories, Department of Chemistry, University of Liverpool, Liverpool L69 7ZD, U.K.
| |
Collapse
|
2
|
Hindle A, Baj K, Iggo JA, Cox DJ, Pask CM, Nelson A, Marsden SP. Modular synthesis of bicyclic twisted amides and anilines. Chem Commun (Camb) 2023; 59:6239-6242. [PMID: 37132397 DOI: 10.1039/d3cc01470c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Bridged amides and anilines display interesting properties owing to perturbation of conjugation of the nitrogen lone-pair with the adjacent π-system. A convergent approach to diazabicyclic scaffolds which contain either twisted amides or anilines is described, based on the photocatalysed hydroamination of cyclic enecarbamates and subsequent cyclisation. The modular nature of the synthesis allows for variation of the degree of 'twist' and hence the properties of the amides and anilines.
Collapse
Affiliation(s)
| | - Krzysztof Baj
- Department of Chemistry, University of Liverpool, Crown Street, Liverpool L69 7ZD, UK
| | - Jonathan A Iggo
- Department of Chemistry, University of Liverpool, Crown Street, Liverpool L69 7ZD, UK
| | - Daniel J Cox
- Redbrick Molecular, The Innovation Centre, 217 Portobello, Sheffield, S1 4DP, UK
| | | | - Adam Nelson
- School of Chemistry, University of Leeds, Leeds, LS2 9JT, UK.
- Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT, UK.
| | | |
Collapse
|
3
|
Abstract
pKa is an important property of a molecule which impacts many fields, such as drug design, catalysis, reactivity, and environmental toxicity. It is often necessary to measure pKa in nonaqueous media due to the poor solubility of an analyte in water, for example, many compounds of pharmaceutical interest. Although NMR methods to measure pKa in water are well established, determining pKa in organic solvents is laborious and problematic. We present an efficient one-shot method to determine the pKa of an analyte in an organic solvent in a single measurement. Diffusion of an acid into a basic solution of the analyte and a set of pH indicators establishes a pH gradient in the NMR tube. The chemical shift of a pH sensitive resonance of the analyte and the pH of the solution are then determined simultaneously as a function of position along the pH gradient by recording a chemical shift image of the NMR tube. The pKa of the analyte is then determined using the Henderson-Hasselbalch equation. The method can be implemented in any laboratory with a gradient equipped NMR high-field spectrometer and is demonstrated for a range of pharmaceutical compounds and inorganic phosphazene bases.
Collapse
Affiliation(s)
- George Schenck
- Department of Chemistry, University of Liverpool, Liverpool L69 7ZD, U.K
| | - Krzysztof Baj
- Department of Chemistry, University of Liverpool, Liverpool L69 7ZD, U.K
| | - Jonathan A Iggo
- Department of Chemistry, University of Liverpool, Liverpool L69 7ZD, U.K
| | - Matthew Wallace
- School of Pharmacy, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, U. K
| |
Collapse
|
4
|
Butler IR, Beaumont M, Bruce MI, Zaitseva NN, Iggo JA, Robertson C, Horton PN, Coles SJ. Synthesis and Structures of 1,1′,2-Tribromoferrocene, 1,1′,2,2′-Tetrabromoferrocene, 1,1′,2,2′-Tetrabromoruthenocene: Expanding the Range of Precursors for the Metallocene Chemist’s Toolkit. Aust J Chem 2021. [DOI: 10.1071/ch19184] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The synthesis, characterisation, and isolation of 1,1′,2-tribromoferrocene and 1,1′,2,2′-tetrabromoferrocene, which are key synthons in ferrocene chemistry, are described. These compounds are prepared using α-halide assisted lithiation. The crystal structures of 1,1′,2-tribromoferrocene, 1,1′,2,2′-tetrabromoferrocene, 1,1′-dibromoruthenocene, and 1,1′,2,2′-tetrabromoruthenocene have been determined and are reported together with a brief discussion of the intramolecular forces involved in the crystal structures.
Collapse
|
5
|
Richards PI, Lawson GT, Bickley JF, Robertson CM, Iggo JA, Steiner A. Polyanionic Ligand Platforms for Methyl- and Dimethylaluminum Arrays. Inorg Chem 2019; 58:3355-3363. [DOI: 10.1021/acs.inorgchem.8b03448] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Philip I. Richards
- Department of Chemistry, University of Liverpool, Crown Street, Liverpool L69 7ZD, U.K
| | - Gavin T. Lawson
- Department of Chemistry, University of Liverpool, Crown Street, Liverpool L69 7ZD, U.K
| | - Jamie F. Bickley
- Department of Chemistry, University of Liverpool, Crown Street, Liverpool L69 7ZD, U.K
| | - Craig M. Robertson
- Department of Chemistry, University of Liverpool, Crown Street, Liverpool L69 7ZD, U.K
| | - Jonathan A. Iggo
- Department of Chemistry, University of Liverpool, Crown Street, Liverpool L69 7ZD, U.K
| | - Alexander Steiner
- Department of Chemistry, University of Liverpool, Crown Street, Liverpool L69 7ZD, U.K
| |
Collapse
|
6
|
Affiliation(s)
- Matthew Wallace
- Department of Chemistry, University of Liverpool, Crown Street, Liverpool, L69 7ZD, United Kingdom
- School of Pharmacy, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, United Kingdom
| | - Dave J. Adams
- Department of Chemistry, University of Liverpool, Crown Street, Liverpool, L69 7ZD, United Kingdom
| | - Jonathan A. Iggo
- Department of Chemistry, University of Liverpool, Crown Street, Liverpool, L69 7ZD, United Kingdom
| |
Collapse
|
7
|
Aboo AH, Bennett EL, Deeprose M, Robertson CM, Iggo JA, Xiao J. Methanol as hydrogen source: transfer hydrogenation of aromatic aldehydes with a rhodacycle. Chem Commun (Camb) 2018; 54:11805-11808. [DOI: 10.1039/c8cc06612d] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A rhodacycle catalyses efficient hydrogenation of aldehydes, deriving the hydrogen from methanol.
Collapse
Affiliation(s)
- Ahmed H. Aboo
- Department of Chemistry, University of Liverpool
- Liverpool
- UK
| | | | - Mark Deeprose
- Department of Chemistry, University of Liverpool
- Liverpool
- UK
| | | | | | - Jianliang Xiao
- Department of Chemistry, University of Liverpool
- Liverpool
- UK
| |
Collapse
|
8
|
Wallace M, Iggo JA, Adams DJ. Probing the surface chemistry of self-assembled peptide hydrogels using solution-state NMR spectroscopy. Soft Matter 2017; 13:1716-1727. [PMID: 28165092 DOI: 10.1039/c6sm02404a] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The surface chemistry of self-assembled hydrogel fibres - their charge, hydrophobicity and ion-binding dynamics - is recognised to play an important role in determining how the gels develop as well as their suitability for different applications. However, to date there are no established methodologies for the study of this surface chemistry. Here, we demonstrate how solution-state NMR spectroscopy can be employed to measure the surface chemical properties of the fibres in a range of hydrogels formed from N-functionalised dipeptides, an effective and versatile class of gelator that has attracted much attention. By studying the interactions with the gel fibres of a diverse range of probe molecules and ions, we can simultaneously study a number of surface chemical properties of the NMR invisible fibres in an essentially non-invasive manner. Our results yield fresh insights into the materials. Most notably, gel fibres assembled using different tiggering methods bear differing amounts of negative charge as a result of a partial deprotonation of the carboxylic acid groups of the gelators. We also demonstrate how chemical shift imaging (CSI) techniques can be applied to follow the formation of hydrogels along chemical gradients. We apply CSI to study the binding of Ca2+ and subsequent gelation of peptide assemblies at alkaline pH. Using metal ion-binding molecules as probes, we are able to detect the presence of bound Ca2+ ions on the surface of the gel fibres. We briefly explore how knowledge of the surface chemical properties of hydrogels could be used to inform their practical application in fields such as drug delivery and environmental remediation.
Collapse
Affiliation(s)
- Matthew Wallace
- Department of Chemistry, University of Liverpool, Liverpool, L69 7ZD, UK.
| | - Jonathan A Iggo
- Department of Chemistry, University of Liverpool, Liverpool, L69 7ZD, UK.
| | - Dave J Adams
- Department of Chemistry, University of Liverpool, Liverpool, L69 7ZD, UK.
| |
Collapse
|
9
|
Abstract
Supramolecular hydrogels are formed via the self-assembly of gelator molecules upon application of a suitable trigger. The exact nature of this self-assembly process has been widely investigated as a practical understanding is vital for the informed design of these materials. Solution-state NMR spectroscopy is an excellent non-invasive tool to follow the self-assembly of supramolecular hydrogels. However, in most cases the self-assembled aggregates are silent by conventional (1)H NMR spectroscopy due to the low mobility of the constituent molecules, limiting NMR spectroscopy to following only the initial assembly step(s). Here, we present a new solution-state NMR spectroscopic method which allows the entire self-assembly process of a dipeptide gelator to be followed. This gelator forms transparent hydrogels by a multi-stage assembly process when the pH of an initially alkaline solution is lowered via the hydrolysis of glucono-δ-lactone (GdL). Changes in the charge, hydrophobicity and relative arrangement of the supramolecular aggregates can be followed throughout the assembly process by measuring the residual quadrupolar couplings (RQCs) of various molecular probes (here, (14)NH4(+) and isopropanol-d8), along with the NMR relaxation rates of (23)Na(+). The initially-formed aggregates comprise negatively charged fibrils which gradually lose their charge and become increasingly hydrophobic as the pH falls, eventually resulting in a macroscopic contraction of the hydrogel. We also demonstrate that the in situ measurement of pH by NMR spectroscopy is both convenient and accurate, representing a useful tool for the characterisation of self-assembly processes by NMR.
Collapse
Affiliation(s)
- Matthew Wallace
- Department of Chemistry, University of Liverpool, Crown Street, Liverpool, L69 7ZD, UK.
| | | | | |
Collapse
|
10
|
Abstract
The magnetic-field-induced alignment of the fibrillar structures present in an aqueous solution of a dipeptide gelator, and the subsequent retention of this alignment upon transformation to a hydrogel upon the addition of CaCl2 or upon a reduction in solution pH is reported. Utilising the switchable nature of the magnetic field coupled with the slow diffusion of CaCl2 , it is possible to precisely control the extent of anisotropy across a hydrogel, something that is generally very difficult to do using alternative methods. The approach is readily extended to other compounds that form viscous solutions at high pH. It is expected that this work will greatly expand the utility of such low-molecular-weight gelators (LMWG) in areas where alignment is key.
Collapse
Affiliation(s)
- Matthew Wallace
- Department of Chemistry, University of LiverpoolCrown Street, Liverpool, L69 7ZD (UK)
| | - Andre Zamith Cardoso
- Department of Chemistry, University of LiverpoolCrown Street, Liverpool, L69 7ZD (UK)
| | - William J Frith
- Unilever R&D Colworth, Colworth Science ParkSharnbrook, Bedfordshire, MK44 1 LQ (UK)
| | - Jonathan A Iggo
- Department of Chemistry, University of LiverpoolCrown Street, Liverpool, L69 7ZD (UK)
| | - Dave J Adams
- Department of Chemistry, University of LiverpoolCrown Street, Liverpool, L69 7ZD (UK)
| |
Collapse
|
11
|
Tang W, Johnston S, Li C, Iggo JA, Bacsa J, Xiao J. Cooperative Catalysis: Combining an Achiral Metal Catalyst with a Chiral Brønsted Acid Enables Highly Enantioselective Hydrogenation of Imines. Chemistry 2013; 19:14187-93. [DOI: 10.1002/chem.201302437] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Indexed: 11/12/2022]
|
12
|
Tang W, Johnston S, Iggo JA, Berry NG, Phelan M, Lian L, Bacsa J, Xiao J. Cooperative Catalysis through Noncovalent Interactions. Angew Chem Int Ed Engl 2013. [DOI: 10.1002/ange.201208774] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
13
|
Tang W, Johnston S, Iggo JA, Berry NG, Phelan M, Lian L, Bacsa J, Xiao J. Cooperative Catalysis through Noncovalent Interactions. Angew Chem Int Ed Engl 2013; 52:1668-72. [DOI: 10.1002/anie.201208774] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2012] [Indexed: 11/05/2022]
|
14
|
Torres A, Molina Perez N, Overend G, Hodge N, Heaton BT, Iggo JA, Satherley J, Whyman R, Eastham GR, Gobby D. High-Pressure In Situ NMR Methods for the Study of Reaction Kinetics in Homogeneous Catalysis. ACS Catal 2012. [DOI: 10.1021/cs300439n] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Alexandre Torres
- Department of Chemistry, University of Liverpool, L69 7ZD Liverpool, United
Kingdom, and
| | - Nieves Molina Perez
- Department of Chemistry, University of Liverpool, L69 7ZD Liverpool, United
Kingdom, and
| | - Gillian Overend
- Department of Chemistry, University of Liverpool, L69 7ZD Liverpool, United
Kingdom, and
| | - Nicholas Hodge
- Department of Chemistry, University of Liverpool, L69 7ZD Liverpool, United
Kingdom, and
| | - Brian T. Heaton
- Department of Chemistry, University of Liverpool, L69 7ZD Liverpool, United
Kingdom, and
| | - Jonathan A. Iggo
- Department of Chemistry, University of Liverpool, L69 7ZD Liverpool, United
Kingdom, and
| | - John Satherley
- Department of Chemistry, University of Liverpool, L69 7ZD Liverpool, United
Kingdom, and
| | - Robin Whyman
- Department of Chemistry, University of Liverpool, L69 7ZD Liverpool, United
Kingdom, and
| | - Graham R. Eastham
- Lucite International, The Wilton Centre, Wilton, Redcar,
TS10 4RF, United Kingdom
| | - Darren Gobby
- Lucite International, The Wilton Centre, Wilton, Redcar,
TS10 4RF, United Kingdom
| |
Collapse
|
15
|
Laybourn A, Dawson R, Clowes R, Iggo JA, Cooper AI, Khimyak YZ, Adams DJ. Branching out with aminals: microporous organic polymers from difunctional monomers. Polym Chem 2012. [DOI: 10.1039/c2py00506a] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
16
|
Ruan J, Iggo JA, Xiao J. Direct Synthesis of 1-Indanones via Pd-Catalyzed Olefination and Ethylene Glycol-Promoted Aldol-Type Annulation Cascade. Org Lett 2010; 13:268-71. [DOI: 10.1021/ol102756m] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jiwu Ruan
- Department of Chemistry, University of Liverpool, Liverpool L69 7ZD, U.K
| | - Jonathan A. Iggo
- Department of Chemistry, University of Liverpool, Liverpool L69 7ZD, U.K
| | - Jianliang Xiao
- Department of Chemistry, University of Liverpool, Liverpool L69 7ZD, U.K
| |
Collapse
|
17
|
Ruan J, Iggo JA, Berry NG, Xiao J. Hydrogen-Bonding-Promoted Oxidative Addition and Regioselective Arylation of Olefins with Aryl Chlorides. J Am Chem Soc 2010; 132:16689-99. [DOI: 10.1021/ja1081926] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jiwu Ruan
- Department of Chemistry, University of Liverpool, Liverpool L69 7ZD, U.K
| | - Jonathan A. Iggo
- Department of Chemistry, University of Liverpool, Liverpool L69 7ZD, U.K
| | - Neil G. Berry
- Department of Chemistry, University of Liverpool, Liverpool L69 7ZD, U.K
| | - Jianliang Xiao
- Department of Chemistry, University of Liverpool, Liverpool L69 7ZD, U.K
| |
Collapse
|
18
|
Heaton BT, Iggo JA, Podkorytov IS, Ponomarenko VI, Selivanov SI, Tunik SP. A rare example of a di-cationic hydrido carbonyl tetra-nuclear cluster, [H2Rh2Pt2(CO)7(PPh3)3]2+. Inorganica Chim Acta 2010. [DOI: 10.1016/j.ica.2009.03.045] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
19
|
Liu J, Jacob C, Sheridan KJ, Al-Mosule F, Heaton BT, Iggo JA, Matthews M, Pelletier J, Whyman R, Bickley JF, Steiner A. The synthesis of, and characterization of the dynamic processes occurring in Pd(ii) chelate complexes of 2-pyridyldiphenylphosphine. Dalton Trans 2010; 39:7921-35. [DOI: 10.1039/b918162h] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
20
|
Bollans L, Bacsa J, Iggo JA, Morris GA, Stachulski AV. The acyl nitroso Diels-Alder (ANDA) reaction of sorbate derivatives: an X-ray and 15N NMR study with an application to amino-acid synthesis. Org Biomol Chem 2009; 7:4531-8. [PMID: 19830306 DOI: 10.1039/b912963d] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We present a study of the acyl nitroso Diels-Alder (ANDA) reaction of sorbate esters and sorbic alcohol derivatives, using alkoxycarbonyl nitroso dienophiles. An optimisation of the reaction conditions for ethyl sorbate is first presented, and the product is used in an efficient synthesis of 5-methylornithine. Structure-reactivity trends in sorbic alcohol (E,E-2,4-hexadien-1-ol) and its acylated analogues are then discussed. We present single-crystal X-ray structural proof for key adducts in both series and present in detail a novel HMBC/HSQC ((1)H-(15)N) criterion for ready distinction of regioisomers arising from such ANDA reactions.
Collapse
Affiliation(s)
- Lee Bollans
- Robert Robinson Laboratories, Department of Chemistry, University of Liverpool, Liverpool, L69 7ZD, UK
| | | | | | | | | |
Collapse
|
21
|
Affiliation(s)
- Jiwu Ruan
- Department of Chemistry, Liverpool Centre for Materials and Catalysis, University of Liverpool, Liverpool L69 7ZD, U.K
| | - Ourida Saidi
- Department of Chemistry, Liverpool Centre for Materials and Catalysis, University of Liverpool, Liverpool L69 7ZD, U.K
| | - Jonathan A. Iggo
- Department of Chemistry, Liverpool Centre for Materials and Catalysis, University of Liverpool, Liverpool L69 7ZD, U.K
| | - Jianliang Xiao
- Department of Chemistry, Liverpool Centre for Materials and Catalysis, University of Liverpool, Liverpool L69 7ZD, U.K
| |
Collapse
|
22
|
Bradd KJ, Heaton BT, Iggo JA, Jacob C, Sampanthar JT, Zacchini S. Multinuclear NMR studies of the products resulting from the reaction of pyridine or 2,2′-bipyridine with [Rh4(CO)12]. Dalton Trans 2008:685-90. [DOI: 10.1039/b715139j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
23
|
Overend G, Iggo JA, Heaton BT, Whyman R. The reaction of mixtures of [Rh4(CO)12] and triphenylphosphite with carbon monoxide or syngas as studied by high-resolution, high-pressure NMR spectroscopy. Magn Reson Chem 2008; 46 Suppl 1:S100-S106. [PMID: 18855346 DOI: 10.1002/mrc.2314] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The fragmentation and redistribution reactions of [Rh4(CO)12-x{P(OPh)3}x] (x = 1-4) with carbon monoxide have been studied using high-resolution, high-pressure NMR spectroscopy. Under the conditions of efficient gas mixing in a high-pressure NMR bubble column, [Rh4(CO)9{P(OPh)3}3] fragments to give mainly [Rh2(CO)6{P(OPh)3}2]; [Rh4(CO)11{P(OPh)3}] is also observed,implying redistribution of the phosphite ligand and/or recombination of the dimers to tetrameric clusters. Fragmentation of[Rh4(CO)10{P(OPh)3}2] is found to be pressure-dependent giving predominantly [Rh2(CO)6{P(OPh)3}2] at low CO pressure (1-40 bar), and increasing amounts of [Rh2(CO)7{P(OPh)3}] at higher (40-80 bar) pressure. Using Syngas (CO : H2 (1 : 1)) instead of CO in the above fragmentations, homolytic addition of H2 to the dimer [Rh2(CO)6{P(OPh)3}2] to give [RhH(CO)3{P(OPh3}] and [RhH(CO)2{P(OPh)3}2] is observed. The distribution of tetrameric species obtained is similar to that obtained under the same partial pressure of CO. On depressurisation/out-gassing of the sample, the original mixture of tetrameric clusters is obtained.
Collapse
Affiliation(s)
- Gillian Overend
- Department of Chemistry, University of Liverpool, Oxford Street, Liverpool L69 7ZD, England, UK
| | | | | | | |
Collapse
|
24
|
Femoni C, Iapalucci MC, Longoni G, Tiozzo C, Zacchini S, Heaton BT, Iggo JA. Sn-centred icosahedral Rh carbonyl clusters: synthesis and structural characterization and 13C–{103Rh} HMQC NMR studies. Dalton Trans 2007:3914-23. [PMID: 17893789 DOI: 10.1039/b708469b] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The reaction of [Rh7(CO)16]3- with SnCl(2).2H2O in a 1 : 1 molar ratio under N2 results in the formation of the new heterometallic cluster, [Rh12Sn(CO)27]4-, in very high yield (ca. 86%). Further controlled additions of SnCl(2).2H2O, or solutions of HCl, or [RhCl(COD)]2, give [Rh12(mu-Cl)2Sn(CO)23]4-. Similarly, addition of HBr to [Rh12Sn(CO)27]4- gives the related cluster [Rh12(mu-Br)2Sn(CO)23]4-. Notably, if the addition of SnCl(2).2H2O to [Rh12Sn(CO)27]4- is carried out under a CO atmosphere, the reaction takes a different course and leads to the formation of the new cluster, [Rh12Sn(mu3-RhCl)(CO)27]4-. All the above clusters have been shown by single-crystal X-ray diffraction studies to have a metal framework based on an icosahedron, which is centred by the unique Sn atom. Their chemical reactivity and 13C-{103Rh} HMQC NMR spectroscopic characterization are also reported.
Collapse
Affiliation(s)
- Cristina Femoni
- Dipartimento di Chimica Fisica ed Inorganica, Università di Bologna, viale Risorgimento 4, 40136 Bologna, Italy
| | | | | | | | | | | | | |
Collapse
|
25
|
Liu J, Heaton BT, Iggo JA, Whyman R, Bickley JF, Steiner A. The Mechanism of the Hydroalkoxycarbonylation of Ethene and Alkene–CO Copolymerization Catalyzed by PdII–Diphosphine Cations. Chemistry 2006; 12:4417-30. [PMID: 16557624 DOI: 10.1002/chem.200501398] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
All the intermediates in the "carboalkoxy" pathway, and their interconversions giving complete catalytic cycles, for palladium-diphosphine-catalyzed hydroalkoxycarbonylation of alkenes, and for alkene-CO copolymerization, have been demonstrated using (31)P{(1)H} and (13)C{(1)H} NMR spectroscopy. The propagation and termination steps of the "hydride" cycles and the crossover between the hydride and carboalkoxy cycles have also been demonstrated, providing the first examples of both cycles, and of chain crossover, being delineated for the same catalyst. Comparison of the propagation and termination steps in the pathways affords new insight into the selectivity-determining steps. Thus, reaction of [Pd(dibpp)(CH(3)CN)(2)](OTf)(2) (dibpp = 1,3-(iBu(2)P)(2)C(3)H(6)) with Et(3)N and CH(3)OH affords [Pd(dibpp)(OCH(3))(CH(3)CN)]OTf, which, on exposure to CO, gives [Pd(dibpp){C(O)OCH(3)}(CH(3)CN)]OTf immediately. Labeling studies show the reaction to be readily reversible. However, the back reaction is strongly inhibited by PPh(3), indicating an insertion/deinsertion pathway. Ethene reacts with [Pd(dibpp){C(O)OCH(3)}(CH(3)CN)]OTf at 243 K to give [Pd(dibpp){CH(2)CH(2)C(O)OCH(3)}]OTf, that is, there is no intrinsic barrier to alkene insertion into the Pd--C(O)OMe bond, as had been proposed. Instead, termination is proposed to be selectivity determining. Methanolysis of the acyl intermediate [Pd(dibpp){C(O)CH(3)}L]X (L = CO, CH(3)OH; X = CF(3)SO(3) (-) (OTf(-)), CH(3)C(6)H(4)SO(3) (-) (OTs(-))) is required in the hydride cycle to give an ester and occurs at 243 K on the timescale of minutes, whereas methanolysis of the beta chelate, required to give an ester from the carbomethoxy cycle, is slow on a timescale of days, at 298 K. These results suggest that slow methanolysis of the beta chelate, rather than slow insertion of an alkene into the Pd--carboalkoxy bond, as had previously been proposed, is responsible for the dominance of the hydride mechanism in hydroalkoxycarbonylation.
Collapse
Affiliation(s)
- Jianke Liu
- Department of Chemistry, Donnan and Robert Robinson Laboratories, University of Liverpool, P.O. Box 147, Liverpool, L69 7ZD, UK
| | | | | | | | | | | |
Collapse
|
26
|
Koshevoy IO, Grachova EV, Tunik SP, Haukka M, Pakkanen TA, Heaton BT, Iggo JA, Podkorytov IS. Synthesis and structural characterization of two novel heterometallic clusters: [Rh4Pt2(CO)11(dppm)2] and [Ru2Rh2Pt2(CO)12(dppm)2]. Dalton Trans 2004. [PMID: 15540134 DOI: 10.1039/b410216a.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Two novel heterometallic octahedral clusters [Rh(4)Pt(2)(CO)(11)(dppm)(2)](1) and [Ru(2)Rh(2)Pt(2)(CO)(12)(dppm)(2)](2) were synthesized by the reaction of [Rh(2)Pt(2)(CO)(6)(dppm)(2)] with [Rh(6)(CO)(14)(NCMe)(2)] and Ru(3)(CO)(12), respectively. Solid state structures of 1 and 2 have been established by a single crystal X-ray diffraction study. Two dppm ligands in 1 are bonded to one platinum and three rhodium atoms, which form an equatorial plane of the Rh(4)Pt(2) octahedron. Two rhodium and two platinum atoms bound to the diphosphine ligands in 2 are nonplanar to give an octahedral C2 symmetric Ru(2)Rh(2)Pt(2)(dppm)2 framework. The (31)P NMR investigation of and (1D, (31)P COSY, (31)P-[(103)Rh] HMQC) and simulation of 1D spectral patterns showed that in both clusters the structures of the M(6)(PP)(2) fragments found in the solid state are maintained in solution.
Collapse
Affiliation(s)
- Igor O Koshevoy
- Department of Chemistry, St. Petersburg State University, Universitetskii pr. 26, St. Petersburg, Staryi Peterhof 198504, Russian Federation
| | | | | | | | | | | | | | | |
Collapse
|
27
|
Koshevoy IO, Grachova EV, Tunik SP, Haukka M, Pakkanen TA, Heaton BT, Iggo JA, Podkorytov IS. Synthesis and structural characterization of two novel heterometallic clusters: [Rh4Pt2(CO)11(dppm)2] and [Ru2Rh2Pt2(CO)12(dppm)2]. Dalton Trans 2004:3893-9. [PMID: 15540134 DOI: 10.1039/b410216a] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Two novel heterometallic octahedral clusters [Rh(4)Pt(2)(CO)(11)(dppm)(2)](1) and [Ru(2)Rh(2)Pt(2)(CO)(12)(dppm)(2)](2) were synthesized by the reaction of [Rh(2)Pt(2)(CO)(6)(dppm)(2)] with [Rh(6)(CO)(14)(NCMe)(2)] and Ru(3)(CO)(12), respectively. Solid state structures of 1 and 2 have been established by a single crystal X-ray diffraction study. Two dppm ligands in 1 are bonded to one platinum and three rhodium atoms, which form an equatorial plane of the Rh(4)Pt(2) octahedron. Two rhodium and two platinum atoms bound to the diphosphine ligands in 2 are nonplanar to give an octahedral C2 symmetric Ru(2)Rh(2)Pt(2)(dppm)2 framework. The (31)P NMR investigation of and (1D, (31)P COSY, (31)P-[(103)Rh] HMQC) and simulation of 1D spectral patterns showed that in both clusters the structures of the M(6)(PP)(2) fragments found in the solid state are maintained in solution.
Collapse
Affiliation(s)
- Igor O Koshevoy
- Department of Chemistry, St. Petersburg State University, Universitetskii pr. 26, St. Petersburg, Staryi Peterhof 198504, Russian Federation
| | | | | | | | | | | | | | | |
Collapse
|
28
|
Heaton BT, Iggo JA, Podkorytov IS, Tunik SP. Application of HMQC spectroscopy to the observation of the metal resonance in polymetallic compounds: the effect of multiple-metal spin transitions. Magn Reson Chem 2004; 42:769-775. [PMID: 15307059 DOI: 10.1002/mrc.1428] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Multiple-metal spin transitions which distort the HMQC spectra of rhodium carbonyl clusters are discussed. These effects are seen whenever the detector nucleus, e.g. 13C or 31P, couples to more than one metal spin and are not restricted to detector ligands occupying edge- or face-bridging sites. These effects are illustrated in, but not limited to, the 13C-{103Rh} and 31P-{103Rh} HMQC spectra of [Rh6(CO)15L], (where L = P(4-F-C6H4)3), [Rh4(CO)11{P(OPh)3}], [Rh6C(CO)15]2- and [Rh2(carboxylate)2PPh3]. The effect is to modulate the intensity and position of the correlations in the metal dimension; cross peaks are displaced from the true chemical shift, additional cross peaks are seen and the intensity of the coherences varies as a function of the preparation delay, d2, and coupling constant, and may go to zero at the conventional value of 1/(2J). Analyses of the relevant spin systems are given together with experimental strategies to overcome these effects.
Collapse
Affiliation(s)
- B T Heaton
- Department of Chemistry, University of Liverpool, PO Box 147, Liverpool L69 7ZD, UK
| | | | | | | |
Collapse
|
29
|
Liu J, Heaton BT, Iggo JA, Whyman R. The Complete Delineation of the Initiation, Propagation, and Termination Steps of the Carbomethoxy Cycle for the Carboalkoxylation of Ethene by Pd–Diphosphane Catalysts. Angew Chem Int Ed Engl 2004; 43:90-4. [PMID: 14694480 DOI: 10.1002/anie.200352369] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Jianke Liu
- Department of Chemistry, Donnan and Robert Robinson Laboratories, University of Liverpool, P. O. Box. 147, Liverpool, UK
| | | | | | | |
Collapse
|
30
|
Liu J, Heaton BT, Iggo JA, Whyman R. The Complete Delineation of the Initiation, Propagation, and Termination Steps of the Carbomethoxy Cycle for the Carboalkoxylation of Ethene by Pd–Diphosphane Catalysts. Angew Chem Int Ed Engl 2004. [DOI: 10.1002/ange.200352369] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
31
|
Affiliation(s)
- Jianke Liu
- Department of Chemistry, Donnan and Robert Robinson Laboratories, University of Liverpool, P. O. Box 147, Liverpool L69 7ZD, UK
| | | | | | | |
Collapse
|
32
|
Iggo JA, Kawashima Y, Liu J, Hiyama T, Nozaki K. High-Pressure NMR Studies on the Alternating Copolymerization of Styrene with Carbon Monoxide Catalyzed by a Palladium(II)−(R,S)-BINAPHOS Complex. Organometallics 2003. [DOI: 10.1021/om0304917] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jonathan A. Iggo
- Department of Chemistry, Donnan and Robert Robinson Laboratories, University of Liverpool, P.O. Box 147, Liverpool L69 7ZD, U.K., Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Yoshida, Sakyo-ku, Kyoto 606-8501, Japan, Conversion and Control by Advanced Chemistry, PRESTO, Japan Science and Technology Corporation (JST), Department of Chemistry & Biotechnology, School of Engineering, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Yasutoyo Kawashima
- Department of Chemistry, Donnan and Robert Robinson Laboratories, University of Liverpool, P.O. Box 147, Liverpool L69 7ZD, U.K., Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Yoshida, Sakyo-ku, Kyoto 606-8501, Japan, Conversion and Control by Advanced Chemistry, PRESTO, Japan Science and Technology Corporation (JST), Department of Chemistry & Biotechnology, School of Engineering, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Jianke Liu
- Department of Chemistry, Donnan and Robert Robinson Laboratories, University of Liverpool, P.O. Box 147, Liverpool L69 7ZD, U.K., Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Yoshida, Sakyo-ku, Kyoto 606-8501, Japan, Conversion and Control by Advanced Chemistry, PRESTO, Japan Science and Technology Corporation (JST), Department of Chemistry & Biotechnology, School of Engineering, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Tamejiro Hiyama
- Department of Chemistry, Donnan and Robert Robinson Laboratories, University of Liverpool, P.O. Box 147, Liverpool L69 7ZD, U.K., Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Yoshida, Sakyo-ku, Kyoto 606-8501, Japan, Conversion and Control by Advanced Chemistry, PRESTO, Japan Science and Technology Corporation (JST), Department of Chemistry & Biotechnology, School of Engineering, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Kyoko Nozaki
- Department of Chemistry, Donnan and Robert Robinson Laboratories, University of Liverpool, P.O. Box 147, Liverpool L69 7ZD, U.K., Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Yoshida, Sakyo-ku, Kyoto 606-8501, Japan, Conversion and Control by Advanced Chemistry, PRESTO, Japan Science and Technology Corporation (JST), Department of Chemistry & Biotechnology, School of Engineering, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| |
Collapse
|
33
|
Farrar DH, Grachova EV, Haukka M, Heaton BT, Iggo JA, Pakkanen TA, Podkorytov IS, Tunik SP. The structure and dynamic behaviour of disubstituted derivatives of [Rh6(CO)16] containing bidentate phosphorus ligands. Inorganica Chim Acta 2003. [DOI: 10.1016/s0020-1693(03)00315-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
34
|
Wolowska J, Eastham GR, Heaton BT, Iggo JA, Jacob C, Whyman R. The effect of mechanistic pathway on activity in the Pd and Pt catalysed methoxycarbonylation of ethene. Chem Commun (Camb) 2002:2784-5. [PMID: 12478745 DOI: 10.1039/b208450c] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
All the intermediates involved in the platinum catalysed methoxycarbonylation of ethene have been characterised by in situ NMR; the low activity of platinum catalysts in this reaction is shown to be due to trapping of the active intermediates by carbon monoxide at every step in the catalytic cycle and to the ready reversibility of the product forming reactions.
Collapse
Affiliation(s)
- Joanna Wolowska
- Department of Chemistry, Donnan and Robert Robinson Laboratories, University of Liverpool, P.O. Box 147, Liverpool, UK L69 7ZD
| | | | | | | | | | | |
Collapse
|
35
|
Clegg W, Eastham GR, Elsegood MRJ, Heaton BT, Iggo JA, Tooze RP, Whyman R, Zacchini S. Synthesis and reactivity of palladium hydrido-solvento complexes, including a key intermediate in the catalytic methoxycarbonylation of ethene to methyl propanoate. ACTA ACUST UNITED AC 2002. [DOI: 10.1039/b202372p] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
36
|
Allevi C, Bordoni S, Clavering CP, Heaton BT, Iggo JA, Garlaschelli L, Seregni C. Multinuclear magnetic resonance studies on substituted rhodium carbonyl clusters. Organometallics 2002. [DOI: 10.1021/om00104a017] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
37
|
Clegg W, Eastham GR, Elsegood MRJ, Heaton BT, Iggo JA, Tooze RP, Whyman R, Zacchini S. Characterization and Dynamics of [Pd(L−L)H(solv)]+, [Pd(L−L)(CH2CH3)]+, and [Pd(L−L)(C(O)Et)(THF)]+ (L−L = 1,2-(CH2PBut2)2C6H4): Key Intermediates in the Catalytic Methoxycarbonylation of Ethene to Methylpropanoate. Organometallics 2002. [DOI: 10.1021/om010938g] [Citation(s) in RCA: 106] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- William Clegg
- Chemistry Department, University of Newcastle, Newcastle-upon-Tyne, U.K. NE1 7RU, Ineos Acrylics, PO Box 90, Wilton, Middlesborough, Cleveland, U.K. TS90 8JE, and Chemistry Department, University of Liverpool, Liverpool, U.K. L69 7ZD
| | - Graham R. Eastham
- Chemistry Department, University of Newcastle, Newcastle-upon-Tyne, U.K. NE1 7RU, Ineos Acrylics, PO Box 90, Wilton, Middlesborough, Cleveland, U.K. TS90 8JE, and Chemistry Department, University of Liverpool, Liverpool, U.K. L69 7ZD
| | - Mark R. J. Elsegood
- Chemistry Department, University of Newcastle, Newcastle-upon-Tyne, U.K. NE1 7RU, Ineos Acrylics, PO Box 90, Wilton, Middlesborough, Cleveland, U.K. TS90 8JE, and Chemistry Department, University of Liverpool, Liverpool, U.K. L69 7ZD
| | - Brian T. Heaton
- Chemistry Department, University of Newcastle, Newcastle-upon-Tyne, U.K. NE1 7RU, Ineos Acrylics, PO Box 90, Wilton, Middlesborough, Cleveland, U.K. TS90 8JE, and Chemistry Department, University of Liverpool, Liverpool, U.K. L69 7ZD
| | - Jonathan A. Iggo
- Chemistry Department, University of Newcastle, Newcastle-upon-Tyne, U.K. NE1 7RU, Ineos Acrylics, PO Box 90, Wilton, Middlesborough, Cleveland, U.K. TS90 8JE, and Chemistry Department, University of Liverpool, Liverpool, U.K. L69 7ZD
| | - Robert P. Tooze
- Chemistry Department, University of Newcastle, Newcastle-upon-Tyne, U.K. NE1 7RU, Ineos Acrylics, PO Box 90, Wilton, Middlesborough, Cleveland, U.K. TS90 8JE, and Chemistry Department, University of Liverpool, Liverpool, U.K. L69 7ZD
| | - Robin Whyman
- Chemistry Department, University of Newcastle, Newcastle-upon-Tyne, U.K. NE1 7RU, Ineos Acrylics, PO Box 90, Wilton, Middlesborough, Cleveland, U.K. TS90 8JE, and Chemistry Department, University of Liverpool, Liverpool, U.K. L69 7ZD
| | - Stefano Zacchini
- Chemistry Department, University of Newcastle, Newcastle-upon-Tyne, U.K. NE1 7RU, Ineos Acrylics, PO Box 90, Wilton, Middlesborough, Cleveland, U.K. TS90 8JE, and Chemistry Department, University of Liverpool, Liverpool, U.K. L69 7ZD
| |
Collapse
|
38
|
Whyman R, Wright AP, Iggo JA, Heaton BT. Carbon monoxide activation in homogeneously catalysed reactions: the nature and roles of catalytic promotersBased on the presentation given at Dalton Discussion No. 4, 10–13th January, 2002, Kloster Banz, Germany. ACTA ACUST UNITED AC 2002. [DOI: 10.1039/b107940a] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
39
|
van der Slot SC, Kamer PCJ, van Leeuwen PWNM, Iggo JA, Heaton BT. Mechanistic Studies of the Hydroformylation of 1-Alkenes Using a Monodentate Phosphorus Diamide Ligand. Organometallics 2001. [DOI: 10.1021/om000785h] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Saskia C. van der Slot
- Institute of Molecular Chemistry, University of Amsterdam, Nieuwe Achtergracht 166, 1018 WV Amsterdam, The Netherlands, and Department of Chemistry, Donnan and Robert Robinson Laboratories, University of Liverpool, P.O. Box 147, Liverpool, U.K. L69 7ZD
| | - Paul C. J. Kamer
- Institute of Molecular Chemistry, University of Amsterdam, Nieuwe Achtergracht 166, 1018 WV Amsterdam, The Netherlands, and Department of Chemistry, Donnan and Robert Robinson Laboratories, University of Liverpool, P.O. Box 147, Liverpool, U.K. L69 7ZD
| | - Piet W. N. M. van Leeuwen
- Institute of Molecular Chemistry, University of Amsterdam, Nieuwe Achtergracht 166, 1018 WV Amsterdam, The Netherlands, and Department of Chemistry, Donnan and Robert Robinson Laboratories, University of Liverpool, P.O. Box 147, Liverpool, U.K. L69 7ZD
| | - Jonathan A. Iggo
- Institute of Molecular Chemistry, University of Amsterdam, Nieuwe Achtergracht 166, 1018 WV Amsterdam, The Netherlands, and Department of Chemistry, Donnan and Robert Robinson Laboratories, University of Liverpool, P.O. Box 147, Liverpool, U.K. L69 7ZD
| | - Brian T. Heaton
- Institute of Molecular Chemistry, University of Amsterdam, Nieuwe Achtergracht 166, 1018 WV Amsterdam, The Netherlands, and Department of Chemistry, Donnan and Robert Robinson Laboratories, University of Liverpool, P.O. Box 147, Liverpool, U.K. L69 7ZD
| |
Collapse
|
40
|
|
41
|
Eastham GR, Tooze RP, Heaton BT, Iggo JA, Whyman R, Zacchini S. Synthesis and spectroscopic characterisation of all the intermediates in the Pd-catalysed methoxycarbonylation of ethene. Chem Commun (Camb) 2000. [DOI: 10.1039/b001110j] [Citation(s) in RCA: 100] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
42
|
Heaton BT, Iggo JA, Podkorytov IS, Smawfield DJ, Tunik SP, Whyman R. Observation of triple-quantum effects in the HMQC spectra of substituted derivatives of Rh6(CO)16 †. ACTA ACUST UNITED AC 1999. [DOI: 10.1039/a903513c] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
43
|
Dolgushin FM, Grachova EV, Heaton BT, Iggo JA, Koshevoy IO, Podkorytov IS, Smawfield DJ, Tunik SP, Whyman R, Yanovskii AI. Synthesis and structural characterisation of the mixed metal clusters [Rh2Pt3(μ-CO)5(CO)4(PPh3)3] and [Rh2Pt2(μ-CO)3(CO)4(PPh3)3]; crystal structure of [Rh2Pt3(μ-CO)5(CO)4(PPh3)3] †. ACTA ACUST UNITED AC 1999. [DOI: 10.1039/a809118h] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
44
|
Collier PJ, Iggo JA, Whyman R, Hall TJ, Iggo JA, Johnston P, Anton Slipszenko J, Wells PB. Solvent and substituent effects on the sense of the enantioselective hydrogenation of pyruvate esters catalysed by Pd and Pt in colloidal and supported forms. Chem Commun (Camb) 1998. [DOI: 10.1039/a803901a] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
45
|
|
46
|
Tunik SP, Podkorytov IS, Heaton BT, Iggo JA, Sampanthar J. Multinuclear NMR studies on substituted derivatives of Rh6(CO)16 in solution1This paper is dedicated to Professor Ken Wade on his retirement for his outstanding contributions to chemistry and particularly to enabling a better understanding of cluster chemistry.1. J Organomet Chem 1998. [DOI: 10.1016/s0022-328x(97)00189-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
47
|
Heaton BT, Iggo JA, Longoni G, Mulley S. Solution and solid-state nuclear magnetic resonance studies on interstitial atoms within transition-metal carbonyl clusters. ACTA ACUST UNITED AC 1995. [DOI: 10.1039/dt9950001985] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
48
|
Blum T, Brown MP, Heaton BT, Hor AS, Iggo JA, Sabounchei JSZ, Smith AK. Phosphine-substituted trigonal-prismatic and octahedral clusters. ACTA ACUST UNITED AC 1994. [DOI: 10.1039/dt9940000513] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
49
|
Bengtsson LA, Heaton BT, Iggo JA, Jacob C, Monks GL, Ratnam J, Smith AK. Kinetics of ligand exchange in rhodium-(I) and -(III) complexes from magnetisation-transfer measurements; the crystal structure of [Rh(NH3)(PPh3)3]ClO4. ACTA ACUST UNITED AC 1994. [DOI: 10.1039/dt9940001857] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
50
|
|