Stephen M. Goldup

Properties and emerging applications of mechanically interlocked ligands

Co-reporter:James E. M. Lewis;Marzia Galli

Chemical Communications 2017 vol. 53(Issue 2) pp:298-312

Publication Date(Web):2016/12/22

DOI:10.1039/C6CC07377H

Mechanically interlocked molecules have a long and rich history as ligands thanks to the key role coordination chemistry has played in the development of high yielding passive template syntheses of rotaxanes and catenanes. In this Feature Article, we highlight the effect of the mechanical bond on the properties of metal ions bound within the sterically hindered environment of the macrocycle cavity, and discuss the emerging applications of interlocked ligands in catalysis, sensing and supramolecular materials.

Metal ions in the synthesis of interlocked molecules and materials

Co-reporter:James E. M. Lewis;Paul D. Beer;Stephen J. Loeb

Chemical Society Reviews 2017 vol. 46(Issue 9) pp:2577-2591

Publication Date(Web):2017/05/09

DOI:10.1039/C7CS00199A

The use of metal ions to template the synthesis of catenanes by Sauvage and co-workers was a pivotal moment in the development of the field of interlocked molecules. In this Review Article we shall examine the different roles metal–ligand interactions play in modern syntheses of interlocked molecules and materials, with a particular focus on seminal contributions and the advantages and disadvantages of employing metal ligand interactions.

Porphyrinoid rotaxanes: building a mechanical picket fence

Co-reporter:T. H. Ngo;J. Labuta;G. N. Lim;W. A. Webre;F. D'Souza;P. A. Karr;J. E. M. Lewis;J. P. Hill;K. Ariga;S. M. Goldup

Chemical Science (2010-Present) 2017 vol. 8(Issue 9) pp:6679-6685

Publication Date(Web):2017/08/21

DOI:10.1039/C7SC03165C

Building on recent progress in the synthesis of functional porphyrins for a range of applications using the Cu-mediated azide–alkyne cycloaddition (CuAAC) reaction, we describe the active template CuAAC synthesis of interlocked triazole functionalised porphyrinoids in excellent yield. By synthesising interlocked analogues of previously studied porphyrin–corrole conjugates, we demonstrate that this approach gives access to rotaxanes in which the detailed electronic properties of the axle component are unchanged but whose steric properties are transformed by the mechanical “picket fence” provided by the threaded rings. Our results suggest that interlocked functionalised porphyrins, readily available using the AT-CuAAC approach, are sterically hindered scaffolds for the development of new catalysts and materials.

Iterative Synthesis of Oligo[n]rotaxanes in Excellent Yield

Co-reporter:James E. M. Lewis, Joby Winn, Luca Cera, and Stephen M. Goldup

Journal of the American Chemical Society 2016 Volume 138(Issue 50) pp:16329-16336

Publication Date(Web):October 4, 2016

DOI:10.1021/jacs.6b08958

We present an operationally simple iterative coupling strategy for the synthesis of oligomeric homo- and hetero[n]rotaxanes with precise control over the position of each macrocycle. The exceptional yield of the AT-CuAAC reaction, combined with optimized conditions that allow the rapid synthesis of the target oligomers, opens the door to the study of precision-engineered oligomeric interlocked molecules.

High yielding synthesis of 2,2′-bipyridine macrocycles, versatile intermediates in the synthesis of rotaxanes

Co-reporter:J. E. M. Lewis, R. J. Bordoli, M. Denis, C. J. Fletcher, M. Galli, E. A. Neal, E. M. Rochette and S. M. Goldup

Chemical Science 2016 vol. 7(Issue 5) pp:3154-3161

Publication Date(Web):27 Jan 2016

DOI:10.1039/C6SC00011H

We present an operationally simple approach to 2,2′-bipyridine macrocycles. Our method uses simple starting materials to produce these previously hard to access rotaxane precursors in remarkable yields (typically >65%) across a range of scales (0.1–5 mmol). All of the macrocycles reported are efficiently converted (>90%) to rotaxanes under AT-CuAAC conditions. With the requisite macrocycles finally available in sufficient quantities, we further demonstrate their long term utility through the first gram-scale synthesis of an AT-CuAAC [2]rotaxane and extend this powerful methodology to produce novel Sauvage-type molecular shuttles.

Correction: High yielding synthesis of 2,2′-bipyridine macrocycles, versatile intermediates in the synthesis of rotaxanes

Co-reporter:J. E. M. Lewis, R. J. Bordoli, M. Denis, C. J. Fletcher, M. Galli, E. A. Neal, E. M. Rochette and S. M. Goldup

Chemical Science 2016 vol. 7(Issue 6) pp:3935-3935

Publication Date(Web):21 Apr 2016

DOI:10.1039/C6SC90027E

Correction for ‘High yielding synthesis of 2,2′-bipyridine macrocycles, versatile intermediates in the synthesis of rotaxanes’ by J. E. M. Lewis et al., Chem. Sci., 2016, DOI: 10.1039/c6sc00011h.

Scalable anti-Markovnikov hydrobromination of aliphatic and aromatic olefins

Co-reporter:Marzia Galli, Catherine J. Fletcher, Marc del Pozo and Stephen M. Goldup

Organic & Biomolecular Chemistry 2016 vol. 14(Issue 24) pp:5622-5626

Publication Date(Web):2016/05/09

DOI:10.1039/C6OB00692B

To improve access to a key synthetic intermediate we targeted a direct hydrobromination-Negishi route. Unsurprisingly, the anti-Markovnikov addition of HBr to estragole in the presence of AIBN proved successful. However, even in the absence of an added initiator, anti-Markovnikov addition was observed. Re-examination of early reports revealed that selective Markovnikov addition, often simply termed “normal” addition, is not always observed with HBr unless air is excluded, leading to the rediscovery of a reproducible and scalable initiator-free protocol.

Competitive formation of homocircuit [3]rotaxanes in synthetically useful yields in the bipyridine-mediated active template CuAAC reaction

Co-reporter:Edward A. Neal and Stephen M. Goldup

Chemical Science 2015 vol. 6(Issue 4) pp:2398-2404

Publication Date(Web):03 Feb 2015

DOI:10.1039/C4SC03999H

We recently identified competitive formation of doubly interlocked [3]rotaxanes as the origin of the non-linear variation in yield of [2]rotaxane with macrocycle size in the bipyridine-mediated AT-CuAAC reaction. Selection of reaction conditions gave [2]rotaxanes in essentially quantitative yield in all cases and hard to access doubly threaded [3]rotaxanes in up to 50% yield in a single, four component coupling. Based on the effect of macrocycle structure on the reaction outcome we propose a detailed mechanism of [3]rotaxane formation.

Selective and general exhaustive cross-coupling of di-chloroarenes with a deficit of nucleophiles mediated by a Pd–NHC complex

Co-reporter:Benjamin J. Groombridge, Stephen M. Goldup and Igor Larrosa

Chemical Communications 2015 vol. 51(Issue 18) pp:3832-3834

Publication Date(Web):04 Feb 2015

DOI:10.1039/C4CC08920K

We report the first example of a general, exhaustive Pd-mediated cross-coupling of polychloroarenes in the presence of a deficit of nucleophiles, mediated by the highly active PEPPSI-IPent catalyst. Our results indicate that this catalyst system may be applicable to the pseudo-living polymerisation of chloroarene monomers.

A Stimuli-Responsive RotaxaneGold Catalyst: Regulation of Activity and Diastereoselectivity

Co-reporter:Marzia Galli;Dr. James E. M. Lewis ;Dr. Stephen M. Goldup

Angewandte Chemie International Edition 2015 Volume 54( Issue 46) pp:13545-13549

Publication Date(Web):

DOI:10.1002/anie.201505464

Abstract

A rotaxane-based Au catalyst was developed and the effect of the mechanical bond on its behavior was studied. Unlike the non-interlocked thread, the rotaxane requires a catalytically innocent cofactor, the identity of which significantly influences both the yield and diastereoselectivity of the reaction. Under optimized conditions, Au^I (the catalyst), Ag^I (to abstract the Cl⁻ ligand), and Cu^I (the cofactor) combine to produce a catalyst with excellent activity and selectivity.

A Stimuli-Responsive RotaxaneGold Catalyst: Regulation of Activity and Diastereoselectivity

Co-reporter:Marzia Galli;Dr. James E. M. Lewis ;Dr. Stephen M. Goldup

Angewandte Chemie 2015 Volume 127( Issue 46) pp:13749-13753

Publication Date(Web):

DOI:10.1002/ange.201505464

Abstract

A rotaxane-based Au catalyst was developed and the effect of the mechanical bond on its behavior was studied. Unlike the non-interlocked thread, the rotaxane requires a catalytically innocent cofactor, the identity of which significantly influences both the yield and diastereoselectivity of the reaction. Under optimized conditions, Au^I (the catalyst), Ag^I (to abstract the Cl⁻ ligand), and Cu^I (the cofactor) combine to produce a catalyst with excellent activity and selectivity.

Correction: High yielding synthesis of 2,2′-bipyridine macrocycles, versatile intermediates in the synthesis of rotaxanes

Co-reporter:J. E. M. Lewis, R. J. Bordoli, M. Denis, C. J. Fletcher, M. Galli, E. A. Neal, E. M. Rochette and S. M. Goldup

Chemical Science (2010-Present) 2016 - vol. 7(Issue 6) pp:NaN3935-3935

Publication Date(Web):2016/04/21

DOI:10.1039/C6SC90027E

Correction for ‘High yielding synthesis of 2,2′-bipyridine macrocycles, versatile intermediates in the synthesis of rotaxanes’ by J. E. M. Lewis et al., Chem. Sci., 2016, DOI: 10.1039/c6sc00011h.

Competitive formation of homocircuit [3]rotaxanes in synthetically useful yields in the bipyridine-mediated active template CuAAC reaction

Co-reporter:Edward A. Neal and Stephen M. Goldup

Chemical Science (2010-Present) 2015 - vol. 6(Issue 4) pp:NaN2404-2404

Publication Date(Web):2015/02/03

DOI:10.1039/C4SC03999H

We recently identified competitive formation of doubly interlocked [3]rotaxanes as the origin of the non-linear variation in yield of [2]rotaxane with macrocycle size in the bipyridine-mediated AT-CuAAC reaction. Selection of reaction conditions gave [2]rotaxanes in essentially quantitative yield in all cases and hard to access doubly threaded [3]rotaxanes in up to 50% yield in a single, four component coupling. Based on the effect of macrocycle structure on the reaction outcome we propose a detailed mechanism of [3]rotaxane formation.

Metal ions in the synthesis of interlocked molecules and materials

Co-reporter:James E. M. Lewis, Paul D. Beer, Stephen J. Loeb and Stephen M. Goldup

Chemical Society Reviews 2017 - vol. 46(Issue 9) pp:NaN2591-2591

Publication Date(Web):2017/04/18

DOI:10.1039/C7CS00199A

The use of metal ions to template the synthesis of catenanes by Sauvage and co-workers was a pivotal moment in the development of the field of interlocked molecules. In this Review Article we shall examine the different roles metal–ligand interactions play in modern syntheses of interlocked molecules and materials, with a particular focus on seminal contributions and the advantages and disadvantages of employing metal ligand interactions.

Selective and general exhaustive cross-coupling of di-chloroarenes with a deficit of nucleophiles mediated by a Pd–NHC complex

Co-reporter:Benjamin J. Groombridge, Stephen M. Goldup and Igor Larrosa

Chemical Communications 2015 - vol. 51(Issue 18) pp:NaN3834-3834

Publication Date(Web):2015/02/04

DOI:10.1039/C4CC08920K

We report the first example of a general, exhaustive Pd-mediated cross-coupling of polychloroarenes in the presence of a deficit of nucleophiles, mediated by the highly active PEPPSI-IPent catalyst. Our results indicate that this catalyst system may be applicable to the pseudo-living polymerisation of chloroarene monomers.

High yielding synthesis of 2,2′-bipyridine macrocycles, versatile intermediates in the synthesis of rotaxanes

Co-reporter:J. E. M. Lewis, R. J. Bordoli, M. Denis, C. J. Fletcher, M. Galli, E. A. Neal, E. M. Rochette and S. M. Goldup

Chemical Science (2010-Present) 2016 - vol. 7(Issue 5) pp:NaN3161-3161

Publication Date(Web):2016/01/27

DOI:10.1039/C6SC00011H

We present an operationally simple approach to 2,2′-bipyridine macrocycles. Our method uses simple starting materials to produce these previously hard to access rotaxane precursors in remarkable yields (typically >65%) across a range of scales (0.1–5 mmol). All of the macrocycles reported are efficiently converted (>90%) to rotaxanes under AT-CuAAC conditions. With the requisite macrocycles finally available in sufficient quantities, we further demonstrate their long term utility through the first gram-scale synthesis of an AT-CuAAC [2]rotaxane and extend this powerful methodology to produce novel Sauvage-type molecular shuttles.

Scalable anti-Markovnikov hydrobromination of aliphatic and aromatic olefins

Co-reporter:Marzia Galli, Catherine J. Fletcher, Marc del Pozo and Stephen M. Goldup

Organic & Biomolecular Chemistry 2016 - vol. 14(Issue 24) pp:NaN5626-5626

Publication Date(Web):2016/05/09

DOI:10.1039/C6OB00692B

To improve access to a key synthetic intermediate we targeted a direct hydrobromination-Negishi route. Unsurprisingly, the anti-Markovnikov addition of HBr to estragole in the presence of AIBN proved successful. However, even in the absence of an added initiator, anti-Markovnikov addition was observed. Re-examination of early reports revealed that selective Markovnikov addition, often simply termed “normal” addition, is not always observed with HBr unless air is excluded, leading to the rediscovery of a reproducible and scalable initiator-free protocol.

Properties and emerging applications of mechanically interlocked ligands

Co-reporter:James E. M. Lewis, Marzia Galli and Stephen M. Goldup

Chemical Communications 2017 - vol. 53(Issue 2) pp:NaN312-312

Publication Date(Web):2016/11/07

DOI:10.1039/C6CC07377H

Mechanically interlocked molecules have a long and rich history as ligands thanks to the key role coordination chemistry has played in the development of high yielding passive template syntheses of rotaxanes and catenanes. In this Feature Article, we highlight the effect of the mechanical bond on the properties of metal ions bound within the sterically hindered environment of the macrocycle cavity, and discuss the emerging applications of interlocked ligands in catalysis, sensing and supramolecular materials.

TOPICS

Abstract

Abstract