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Rebecca Melen

Professor Rebecca Melen

(she/her)

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Available for postgraduate supervision

Teams and roles for Rebecca Melen

Overview

Research in the Melen group focuses on exploiting the reactivity of main group (p-block) elements to design new reagents and catalysts for sustainable chemical synthesis. Traditionally associated with transition metals, catalytic activity is now being uncovered across the p-block, offering cheaper, less toxic, and complementary alternatives.

A major focus has been the development of borane catalysts as main group replacements for precious metals in carbene transfer reactions, providing new pathways in diazo chemistry (Angew. Chem. Int. Ed. 2020; Chem 2020). The group has also pioneered the use of "frustrated radical pairs", demonstrating that single-electron pathways can drive bond formation in contrast to classical two-electron processes (Chem. Rev. 2023; J. Am. Chem. Soc. 2021). These advances have enabled the understanding of p-block reactivity, and highly selective C–H and C–C bond-forming reactions (Chem 2024), broadening the scope of p-block catalysis. Alongside this, we are developing the use of new methodologies in p-block chemistry including flow electrochemistry (Green Chem., 2024) and microwave chemistry (J. Am. Chem. Soc. 2024).This work has been recognised through numerous awards, including the RSC Sir Geoffrey Wilkinson Prize (2025), the Philip Leverhulme Prize (2022), the RSC Harrison Meldola Memorial Prize (2019), and the Clara Immerwahr Award (2016).

Research projects in the Melen group draw together multiple areas of chemistry including organic and inorganic synthesis, main group chemistry, and catalysis, and employ a wide range of physical characterisation methods (multinuclear NMR spectroscopy, EPR spectroscopy, and X-ray diffraction) supported by computational studies. Alongside fundamental discovery, the group collaborates with pharmaceutical, defence, semiconductor and petrochemical industries to develop new p-block materials and methodologies for industrial applications.

 

Links:

Group website: http://www.melengroup.com

Publication

2025

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

2011

2010

2009

2008

Articles

Book sections

Research

Reimagining p-Block Chemistry for Synthesis and Industrial Innovation

Catalyst Design | Metal-Free Catalysis | Reaction Mechanisms | Compound Characterisation | Industrial Applications

 

Catalysis underpins over 85% of modern chemical manufacturing, from pharmaceuticals and agrochemicals to fuels and materials. However, the dominance of rare and toxic transition metals as catalysts raises major challenges: high costs, environmental damage from mining and refining, and issues of toxicity and waste in end-use applications. My research programme tackles these challenges by pioneering sustainable alternatives based on p-block (main group) elements, an underexplored part of the periodic table. Through careful tuning of reactivity and mechanism, we develop catalysts and reagents that are not only metal-free but also deliver complementary reactivity to traditional transition-metal systems.

Research projects in the Melen group draw together organic and inorganic synthesis, catalysis, main group chemistry, and mechanistic studies, supported by a wide range of characterisation techniques (multinuclear NMR, X-ray diffraction) and computational modelling. This multidisciplinary approach has led to breakthroughs in sustainable catalysis, new mechanistic paradigms, and translation into industrial technologies. Below are several areas of research actively ongoing within our group.

 

Metal-Free Catalysts That Replace Precious Metals

A central strand of our research is the design of catalysts from p-block elements such as boron, aluminium, and phosphorus. Using ligand design to control steric and electronic properties, we have developed catalysts capable of mediating hydrogenation, hydroboration, C–C bond formation, and carbene transfer.

In a defining contribution, we showed that boron Lewis acids can catalyse carbene transfer from diazo compounds, a role previously dominated by rhodium and other precious metals. These studies led to new, metal-free pathways for generating reactive carbenes and forming complex carbon–carbon frameworks under mild conditions (Chem 2020, 6, 2364; Angew. Chem. Int. Ed. 2020, 59, 15492). More recently, we reported boron-catalysed C–S bond formation, enabling access to sulfur-containing motifs that are central to pharmaceuticals and agrochemicals (Chem 2024, 10, 2901). These advances highlight the power of main group elements to both mimic and transcend traditional transition-metal reactivity.

 

Challenging Mechanistic Assumptions: Single-Electron Reactivity

Historically, main group reactivity has been dominated by two-electron processes. Our work has challenged this paradigm by demonstrating that single-electron transfer (SET) pathways can provide alternative, lower-energy routes to bond formation.

In particular, we have pioneered the use of frustrated radical pairs (derived from frustrated Lewis pairs) to enable radical reactivity in main group chemistry. Through experimental studies combined with spectroscopy and computation, we uncovered SET pathways in bond-forming reactions that had previously been assumed to proceed via classical two-electron mechanisms (J. Am. Chem. Soc. 2021, 143, 4451; Chem. Rev. 2023, 123, 9653). This has opened new carbon–carbon bond-forming methodologies and provided a blueprint for expanding the radical chemistry of the p-block.

 

Improving Scientific Standards: Rethinking Elemental Analysis

Rigorous characterisation of new compounds is essential. In one of our most widely discussed studies, we were involved in an international evaluation of elemental analysis standards, demonstrating that the long-standing requirement for ±0.4% agreement with theoretical values was statistically unsound. This work, published in ACS Cent. Sci. (2022, 8, 855), sparked broad debate, was highlighted in Chemistry World, ACS Cent. Sci., and Science, and directly influenced new publisher policies. This project illustrates how improving analytical rigour can enhance data integrity and reproducibility across chemistry.

 

Industrial Applications and Broader Impact

Alongside fundamental discoveries, our research has significant industrial relevance, with projects spanning pharmaceuticals, energy, and materials science. By collaborating with global companies and research organisations, we translate new concepts in p-block chemistry into practical technologies from sustainable synthesis to advanced materials. These partnerships demonstrate how fundamental research into main group elements can have a tangible impact on green energy, healthcare, and next-generation materials.

Teaching

CH5202 Structure, bonding and reactivity in compounds of the p and d-block elements

CH3404 Asymmetric Synthesis of Pharmaceuticals and Natural Products

Details of modules can be found in course finder.

Biography

Professional Appointments

2021–Current Professor in Inorganic Chemistry, Cardiff University, UK. 

2019–2021 Reader in Inorganic Chemistry, Cardiff University, UK. 

2017–2019 Senior Lecturer in Inorganic Chemistry, Cardiff University, UK. 

2015–2016 Visiting Professorship with Prof. Dr. Martin Oestreich as part of the Clara Immerwahr Award, Technische Universität Berlin, Germany. 

2014–2017 Lecturer in Inorganic Chemistry, Cardiff University, UK. 

2013–2014 Alexander von Humboldt Fellowship with Prof. Dr. Lutz H. Gade, Ruprecht-Karls-Universität Heidelberg, Germany. 

2012–2013 Postdoctoral Fellowship with Prof. Douglas W. Stephan, University of Toronto, Canada.  

 

Education and Training

2012 PhD “Catalytic Versus Stoichiometric Dehydrocoupling Using Main Group Metals”, Department of Chemistry, University of Cambridge, UK. Prof. Dominic S. Wright 

2011 MA, Department of Chemistry, University of Cambridge, UK. 

2008 MSc, Department of Chemistry, University of Cambridge, UK. 

2008 BA, Department of Chemistry, University of Cambridge, UK. 

 

Honours and awards

2025 RSC Sir Geoffrey Wilkinson Prize

2022 Philip Leverhulme Prize

2022 Elected Fellow of the Learned Society of Wales 

2019 Bürgenstock Conference Fellowship

2019 RSC Harrison Meldola Memorial Prize 

2019 Learned Society of Wales, Dillwyn Medal

2018 Thieme Journal Award Winner.  

2016 Fellow Higher Education Academy.  

2016 Clara Immerwahr award 

2013 RSC Dalton Young Researcher Award  

Professional memberships

Learned Society of Wales 

Royal Society of Chemistry
 
 

Speaking engagements

Total 168 presentations at Universities and Conferences. This includes invited departmental seminars in the UK, USA, Australia, Germany, Canada, France, India, Japan, Netherlands, Spain, and Switzerland, as well as invited keynote/plenary talks at national and international conferences.

Committees and reviewing

Organisation of Conferences: 

2025               Co-chair of the Global Virtual Symposia ACS Fall 2025 Symposium “Hydroelementation Reactions”.

2025               Canada-UK Conference on Inorganic Chemistry, Quebec City, Canada (organising committee).

2025               Cardiff Chemistry Conference, Cardiff, UK (organising committee).

2018                MICRA, Cardiff, UK (organising committee).

2018                Dalton Conference, Coventry, UK (organising committee).

2017                SCI Hot Topics in Organic Synthesis, SCI Headquarters, London, UK (organising committee). 

2017                Main Group Interest Group Meeting,  Burlington House, London, UK (organising committee). 

2017                RSC Sir Geoffrey Wilkinson Dalton Poster Symposium (chair organising committee). 

2017                RSC Twitter Poster Conference (inorganic subject chair).

2016                Dalton Conference, Coventry, UK (poster session). 

2015–2023      Cardiff Chemistry Conference, Cardiff, UK (organising committee).

 

Academic Responsibilities:

027–2029          Research Excellence Framework Panel member UOA 8.

 

2023–Current    Royal Society URF Research Appointment Panel A(ii).

 

2023–Current    External Examiner Undergraduate Studies, University of Lincoln.

 

2023–2024        Dalton Division Awards Subcommittee RSC.

 

2023–Current    Associate Editor of EES Catalysis (RSC).

 

2021–2023        External Examiner Undergraduate Studies, Trinity College Dublin.

 

2022–Current    ACS Catalysis Editorial Advisory Board (ACS).

 

2022–Current    External reviewer of promotion applications (×4).

 

2021–Current    Co-Guest Editor for EurJIC and ChemCatChem special issue.

 

2020–Current    AsianJOC, ChemEurJ, Chem, Chem Catalysis, and Organometallics Advisory Board.

 

2021–2025        EPSRC responsive mode/interview Panel Member (×5).

 

2019–Current    Editor of EIBC (Wiley).

 

2016–2019        SCI Young Chemists’ Panel Member.

 

2016–Current    Member of the EPSRC Associate Peer Review College.

 

2016–2017        Dalton Division Travel Grants Subcommittee RSC.

 

2016–2022        Treasurer of the Main Group Interest Group of the RSC.

 

2016                  Guest Editor for a Special Issue of Dalton Transactions.

 

2016–2019        Associate Editor of EIBC (Wiley).

 

2015–2017        Dalton Division Awards Subcommittee RSC.

 

2015–2021        Dalton Division Council member of the RSC.

 

2015–2019        Treasurer of the South East Wales local section of the RSC.

 

2014–Current    Peer Review of national and international research grants.

 

2014–Current    Peer review of manuscripts for Science, Elsevier, RSC, ACS and Wiley VCH journals/books.

 

2014–Current    Internal/External PhD examiner: UK (×9), Overseas (×6). External MRes examiner: UK (×1).

 

 

Institutional responsibilities:

2024–Current    Deputy Director of Research.

2024–Current    EPSRC Expert Group.

2021–Current    Research Committee.

2014–Current    Organising committee for the annual Cardiff Chemistry Conference.

 

Supervisions

Current supervision

Parth Bhavsar

Parth Bhavsar

Sampurna Das

Sampurna Das

Aleksandra Gorecka

Aleksandra Gorecka

Nusaybah Alotaibi

Nusaybah Alotaibi

Tribani Boruah

Tribani Boruah

Tanmay Kanji

Tanmay Kanji

Taylor Wilde

Taylor Wilde

Ho Pang Mak

Ho Pang Mak

Contact Details

Email MelenR@cardiff.ac.uk
Telephone +44 29208 79667
Campuses Translational Research Hub, Room 0.54, Maindy Road, Cathays, Cardiff, CF24 4HQ

Research themes

Specialisms

  • Inorganic chemistry
  • Organic chemistry
  • Homogeneous catalysis
Fifteen REF sub-panel members for Cardiff University

Fifteen REF sub-panel members for Cardiff University

09 September 2025

Sir Geoffrey Wilkinson Prize 2025 for Cardiff scientist

Sir Geoffrey Wilkinson Prize 2025 for Cardiff scientist

01 July 2025

Academics win prestigious Leverhulme Trust Prizes

Academics win prestigious Leverhulme Trust Prizes

25 October 2022

External profiles