Projects per year
Professor of Synthetic & Pharmaceutical Chemistry; Chair, Chemistry Organic MSc Examination Board; Chair, CHE Industrial Advisory Panel; CHE Employability Director, CHE NSS Champion; and a member of the CHE Special Circumstances Panel, CHE Promotions Committee, CHE Athena Swan Committee and CHE Executive.
The Stephenson group works in the field of synthetic organic chemistry and methodologies for enantioselective synthesis. Our targets are functional molecules with a variety of applications including functionalised calix[n]arenes and multi-cavitands as novel receptors and switchable NLOphores, helicenes for use in Two Photon Circular Dichroism (TPCD), bioactive compounds targeting neglected tropical diseases (NTDs) and as potential anti-cancer leads by the inhibition of ubiquitin ligase, and novel reagents for cellulose derivatisation for biocomposite applications. Current projects in the group also focus on the concept of double/multi-kinetic resolution (multi-KR), and asymmetric ‘click’ chemistry, and the applications of these new concepts in the synthesis of tetrathiahelicenes (multi-KR) and hexaazahelicenes (our ‘click’ helicenes). International collaborations play a significant part in our work; with photophysics experts at the University of Leuven for nonlinear optics (NLO) and TPCD, with laboratories in subSaharan Africa in the ‘Open Lab Africa’ project, and with three research groups at the South University of Science and Technology of China (SUSTech) as part of the UEA-SUSTech Split-Site PhD Programme.
Dr G. Richard Stephenson, FRSC, CChem, SFHEA, started his career as a Research Fellow at the Australian National University (Canberra) and a Senior Research Fellow at Girton College, Cambridge, before moving to UEA, first as a Royal Society University Research Fellow, and then as Lecturer, Senior Lecturer and Reader. In 2000, Stephenson was Visiting Professor at the Université de Caen; in 2001, Invited Professor at Université Paris VI; and in 2003, he was Invited Professor at the Université Catholique de Louvain. Stephenson held a Visiting Fellowship at the Australian National University in 2006, and was UEA’s lead investigator in the ‘Innovative Synthesis: Chemistry and Entrepreneurship’ (IS:CE-chem) and ‘Academy-Industry Chemistry-Channel’ (AIcc) EU Interreg IVA projects (2009-2015), which together have contributed 2.5 million euros of ERDF funding to the Organic Sector in the School of Chemistry and supported 15 PhD students in the Science Faculty at UEA. Stephenson is a Fellow of the Royal Society of Chemistry (RSC) and a member of the American Chemical Society (ACS).
Stephenson, G. Richard; Doulcet, Julien.
Kinetic resolutions of tetrathiahelicene derivatives by (–)-sparteine mediated enantioselective lithiation.
Chem. Eur. J. 2015, 21, 18677-18689
Stephenson, G. Richard; Doulcet, Julien.
Novel Asymmetric Formylation of Aromatic Compounds: Enantioselective Synthesis of Formyl 7,8-Dipropyltetrathiahelicenes.
Chem. Eur. J. 2015, 21, 13431-13436)
Bew, Sean P.; Stephenson, G. Richard; Rouden, Jacques; Ashford, Polly-Anna; Hiatt-Gipson, Glyn D.: Bourane, Manuel; Charvet, Agathe; Dalstein, Virginie M. D.; Jauseau, Raphael; Hiatt-Gipson, Glyn D.; Martinez-Lozano, Luis A
Bioinspired, Base- & Metal-free, Mild, Decarboxylative Aldol Activation of Malonic Acid Half Thioesters Under Phase-Transfer Reaction Conditions.
Adv. Synth. Catal. 2015, 357, 1245-1257
Bew, Sean P.; Stephenson, G. Richard; Rouden, Jacques; Godemert, I.; Seylani, Haseena; Martinez-Lozano, Luis A.
Gaining an insight into reactivity differences between malonic acid half thioester (MATH) and malonic acid half oxyesters (MAHO).
Chem. Eur. J. 2017, 23, 4557–4569
Tinson, Ryan A. J.; Hughes, David L.; Ward, Leanne; Stephenson, G. Richard
Unusual Nucleophilic Addition of Grignard Reagents in the Synthesis of 4-Amino-pyrimidines.
ACS Omega, 2018, 3, 8937-8944
- Member COST D2 Working Group
- Coordinator COST D4 Working Group
- Coordinator EU TMR RTN
- Coordinator COST D14 Working Group
- Member COST COST D26 Working Group
- Interreg Trans-Manche projects IS:CE chem and AI chem Chennel
International invitations (professional):
- March-April 2006: Visiting Fellow: Australian National University
- October 2003: Invited Professor: Université Catholique de Louvain (CHIM 3430)
- October 2002: Colloque 3e Cycle Universitaire de Suisse Occidental, (Commission Scientifique pour L'Enseignment du 3e Cycle en Chimie)
- April 2001: Invited Professor: Université PARIS VI
- 2004-5 - "Handbook of Functionalised Organometallics"[Wiley-VCH, Weinheim, (ISBN 3-527-31131-9)]"
- 2004 - "Bioorganometallic Chemistry" [Wiley-VCH, Weinheim, (ISBN 3-527-30990-X)]
- 2001 - "Science of Synthesis; Houben-Weyl Methods of Molecular Transformations" [Georg Theime Verlag, Stuttgart (ISBN 3-13-112131-9)]
‘Highlights: Organic Chemistry’ in Chemistry and Industry, published by the Society of Chemical Industry
- Senior Fellow of the Higher Education Academy
- Fellow of the Royal Society of Chemistry, Chartered Chemist,
- Member of the American Chemical Society
Key Research Interests and Expertise
Double and Multi-Kinetic Resolution
Enantioselective synthesis is an important goal and conventional methods rely on asymmetric induction or classical/kinetic resolution, in which a chiral auxiliary is used at a specific step to gain access to non-racemic samples. In our multi-KR approach, the all the steps of a retrosynthetic analysis are assessed for the possibility of chiral intervention and prioritised. As the synthesis proceeds, a series of kinetic resolutions progressively improves the enantiomeric excess (e.e.) until the level is high enough to allow the product crystallise as a single enantiomer. Whereas the conventional approach can sometime require extensive and time-consuming optimisation at a specific step (a potential ‘bottle-neck’), the multi-KR approach allows additional KR steps to be introduced into the synthetic plan to further improve e.e. if the original selection for KRs lack the required levels of stereorecognition. There are two important advantages to multi-KR: no individual step needs full optimisation, and once enantiopurity has been achieved, further work to optimise stereoselectivity improves the chemical yield of the synthesis (e.g. for scale-up), not the enantioselectivity. The double-KR approach has been exemplified in our work on tetrathiahelicines (see selected publications), and research in this area now moves to apply the concept in general to the synthesis of natural products and bioactives.
Asymmetric ‘click’ chemistry
Because the 1,2,3-triazoles lack chirality, until our work in this area, the famous Sharpless/Mendal CuAAC ‘click’ reaction had been performed only once with chiral auxiliaries on the copper. Our aim is to generalise the asymmetric variant of ‘click’ chemistry by studying the desymetrisation of diynes, including, for the first time, conceptually important meso diynes. Compared with the many thousands of papers on ‘click’ chemistry, there are still only a handful on asymmetric ‘click’ chemistry, but this total grows more rapidly as other research groups pick up this topic which is set to become a major and highly competitive research area. Our aim is to develop the method as a general strategy in asymmetric synthesis to take prochiral diyne starting materials on to enantiopure final products which exploit the properties of 1,2,3-triazoles as ligating (including bioligating) sites in novel series of chiral ligands and bioactives, and as part of the fused aromatic ring systems of helicenes (see below).
Enantioselective Synthesis of Helicenes
The twisted pi systems of helicenes provide a unique class of organic structures in which the two ends of a series of ortho-fused aromatic rings can no longer lie in the same plane because they overlap. Such structures are chiral and when there is sufficient overlap, the barrier to epimerisation is high. Our interest in helicenes springs from their potential in nonlinear optics (NLO), and particularly their predicted but as yet unrealised special suitability for use in Two Photon Circular Dichroism (TPCD), a goal which will lead ultimately to a new method of bioimaging which combines the confocality of two-photon absorption with the sensitivity to the stereochemical environment demonstrated in circular dichroism spectroscopy. Current target molecules in the group include tetrathiahelicenes addressed by a one-pot double-KR approach, and a new class of hexaazahelicenes than can be accessed by a double asymmetric ‘click’ strategy. Both conventional ‘single-dipole full-turn’ and our novel ‘double-dipole half turn’ designs are targets for the group.
Ubiquitin Ligase Inhibitors
Ubiquitin ligases are enzymes which are implicated in tumour outgrowth and spread and so are attractive targets for new approaches to develop anticancer bioactives (PI: Chantry). As a synthetic chemistry component of a larger collaborative project with Chantry, Hemmings, Page (Schools of Biological Sciences and Chemistry) we are working on the design and synthesis of new and more potent inhibitors for E3 ubiquitin ligases employing a fragment-based strategy which involves the synthesis of small binding motifs and linkers, assisted by modelling studies to aid the molecular design process.
‘Open Lab Africa’
The neglected tropical diseases (NTDs) still cause great human suffering in some of the poorest countries on the planet. The UEA ‘Open Lab Africa’ project is adopting a fresh and novel approach to this global challenge in a collaborative effort with Duvendack, Gallash, Hamilton, McDermott, (Schools of Development Studies, Law, and Pharmacy) at UEA and Frey (University of Southampton) together with institutes in Cameroon, Democratic Republic of the Congo, Ghana, Kenya, Tanzania, and Uganda. The synthetic chemistry part of the project involves the identification and synthesis of new lead structures and their analogues in a fragment-based approach towards new capabilities to address particular NTDs which are of most serious or growing concern in the subSaharan region of Africa. The project combines an Open Lab-Book and Open Med-Chem approach which invites institutes and specialists around the world to follow, advise, and even join in the project.
Synthesis and evaluation of X-ray structure inspired ubiquitin ligase inhibitors as anticancer lead compounds
1-Oct-20 – 30-Sept-23
Novel Water Resistant Flax Bio-composites
21-Jun-20 – 20 Sept-21
Asymmetric 'click'-synthesis of helicenes
27-Mar-17 – 26-Mar-20
Towards fully sustainable high-performance biocomposites for lightweight vehicles
01-Apr-16 – 31-Mar-18
EU Interreg IVA
Academie-Industrie Chemistry Channel (A-I chem channel)
02-Nov-11 – 30-June-2015
Highly anisotopic helicene-based NLOphores for two photon circular dichroism
01-Oct-09 – 30-Sept-13
EU Interreg IVA
Innovative Synthesis: Chemistry and Entrepreneurship (IS:CE chem)
01-June-08 – 30-Sept-13
Daphne Jackson Trust
Introducing a new twist to photonics
Fellowship for K. Hamilton
01-July-08 – 30-June-10
Nanoscale and molecular photonics
Meech, SR, Cammidge, AN, Andrews, DL, Reading, M, Stephenson, GR, Mayes, AG and Barker, S
01-Sep-05 - 31-Aug-07
EU COST Chemistry D26: European collaboration for calculation inspired synthesis of NLO responsive aryl and helicenyl organometallics Stephenson, GR
01-Jul-06 - 31-Jul-07
Enantioselective organoiron / heterocycloaddition approach to hippeastrine
01-Mar-03 - 31-Mar-06
European collaboration to synthesise and evaluate NLO compounds with novel photorefractive properties
CASE Award: Custom synthesis and automated evaluation to optimise the asymmetric Heck reaction
01-Oct-01 - 30-Sep-04
Organometallic dipoles with NLO properties
Stephenson, G R
01-Mar-98 – 28-Feb-02
Studentship: Synthesis of stable-isotope-labelled lipids for nutritional studies
Stephenson, G R and Shepherd, MJ (CSL)
01-Oct-98 - 30-Sep-01
CASE Award: Develop catalytic versions of stoichiometric organometallic reactions
Stephenson, G R
01-Oct-98 - 30-Sep-01
Research Group Membership
- James Tonkin
- James Sharpe*
- Jake Rigby*
* indicates collaborative project
Postdoctoral Visiting Fellows
- Lloyd Sayer
- Rhoda Beskeni
Senior Technical Officer
- Adam Wright
Areas Of Expertise
ENANTIOSELLECTIVE SYNTHESIS||HELICENES||MULTI-KR||ASYMMETRIC 'CLICK' CHEMISTRY||BIOTECHNOLOGY||NATURAL PRODUCTS, CHEMISTRY OF||NEW MATERIALS||ORGANIC MATERIALS||ORGANOMETALLIC CHEMISTRY OF IRON
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- 55 Article
Synthesis of novel stilbene–coumarin derivatives and antifungal screening of monotes kerstingii-specialized metabolites against fusarium oxysporumFotso, G. W., Ngameni, B., Storr, T. E., Ngadjui, B. T., Mafu, S. & Stephenson, G. R., 25 Aug 2020, In : Antibiotics. 9, 9, p. 1-13 13 p., 537.
Research output: Contribution to journal › ArticleOpen AccessFile2 Citations (Scopus)19 Downloads (Pure)
Steverding, D., Sidjui, L. S., Ferreira, É. R., Ngameni, B. N., Folefoc, G. N., Mahiou-Leddet, V., Ollivier, E., Stephenson, G. R., Storr, T. & Tyler, K., Jun 2020, In : Journal of Natural Medicines. 74, 3, p. 606–611 6 p.
Research output: Contribution to journal › ArticleOpen AccessFile2 Citations (Scopus)26 Downloads (Pure)
Asymmetric Oxidation of Enol Derivatives to α-Alkoxy Carbonyls Using Iminium Salt Catalysts: A Synthetic and Computational StudyBulman Page, P. C., Almutairi, S. M., Chan, Y., Stephenson, G. R., Gama, Y., Goodyear, R. L., Douteau, A., Allin, S. M. & Jones, G. A., 18 Jan 2019, In : The Journal of Organic Chemistry. 84, 2, p. 544–559 16 p.
Research output: Contribution to journal › ArticleOpen AccessFile3 Citations (Scopus)17 Downloads (Pure)
Induction of Planar Chirality Using Asymmetric Click Chemistry by a Novel Desymmetrisation of 1,3-Bisalkynyl FerrocenesWright, A. J., Hughes, D. L., Bulman Page, P. C. & Stephenson, G. R., 24 Nov 2019, In : European Journal of Organic Chemistry. 2019, 43, p. 7218-7222
Research output: Contribution to journal › ArticleOpen AccessFile6 Citations (Scopus)33 Downloads (Pure)
Monaco, S., Stephenson, G., Bulman Page, P., Hemmings, A., Angulo, J. & Chantry, A., 3 Dec 2018, In : Chemistry - A European Journal. 24, 67, p. 17677-17680 4 p.
Research output: Contribution to journal › ArticleOpen AccessFile13 Citations (Scopus)27 Downloads (Pure)