Physical Organic Chemistry
Molecular orbital symmetry (use of Walsh diagrams)
Synthetic organic chemistry
I completed my undergraduate studies in chemistry in University College Dublin in 2006, and undertook a Ph.D. in the laboratory of Prof. Declan Gilheany in UCD in 2007, funded by IRCSET. During my Ph.D. I worked primarily on the mechanism of the Wittig reaction and on developing a novel chromatography-free method for phosphine oxide removal from reaction mixtures, but also worked on the synthesis of chiral phosphines for use in catalysis. I obtained my Ph.D. in 2011, and continued in postdoctoral work in UCD until 2014, during which time I focused on the mechanisms of phosphonium salt & ylide hydrolysis and alcoholysis, on the synthesis of strained bicyclic amines, and on the development of the phosphine oxide removal technique for industrial application. In 2014, I was awarded an Alexander von Humboldt Postdoctoral Fellowship to carry out research in the laboratory of Prof. Herbert Mayr in Ludwig Maximliians Universität in Munich, Germany. My research in LMU was concentrated on the progression of a consistent rationale for understanding reactivity in organic chemistry (applications included rationalising the reactivity of ambident nucleophiles, and the electrophilicity of vinyl cations), and on the development of a quantitative organic Lewis basicity scale.
In November 2016 I joined the Chemistry Department in University College Cork as a lecturer in organic chemistry. In July 2017 I was nominated by the Institute of Chemistry Ireland (ICI) to attend the EuChemS Young Investigator Workshop in Germany. Since then, I have built up a research group of ten members (10 × PhD students, 1 Postdoctoral Researcher now finished). We will welcome two further PhD students and a Postdoctoral Researcher into the group in September 2022. I am a Funded Investigator in the Molecules I theme of the SFI-funded SSPC Research Centre (Synthesis and Solid State Pharmaceutical Centre), and have recently started a project funded by the SFI Frontiers for the Future Programme.
My research interests include:
- Green & Sustainable Organic Chemistry, including use of "green" solvents and solvent-free reactions
- Development of novel organocatalysts for new synthetic methodology
- CO2 activation and utilisation
- Organophosphorus chemistry, especially the Wittig reaction
- Ambident nucleophilicity and Gibbs energy surfaces for chemical reactions
- Development of less wasteful alternatives to the Protecting Group Methodology.
- Physical organic chemistry (determination of reaction mechanisms, quantitative Lewis basicity scales, Marcus theory).
Research InterestsFor descriptions of research projects, see https://byrnechemistry.wordpress.com/current-projects/
1. Carbon Dioxide Activation & Utilisation (in collaboration with Dr. Gerard McGlacken in UCC): Carbon dioxide utilisation continues to capture the attention of chemists due to the ever-increasing global levels of CO2 gas and the negative effects of global warming.[1,2] The major cause of this is the burning of fossil fuels, deforestation, and our modern industrialised lifestyle. However, CO2 is a valuable and environmentally friendly C1 building block for the synthesis of various value-added chemicals. Many medicinally important compounds contain the elements of CO2 within their structure, including α,β-unsaturated carboxylic acids and enoates. CO2 has an inherently low reactivity and therefore must be activated before it can be converted into another product. In this project, a novel strategy has been developed for utilisation of CO2 as a chemical feedstock, enabling synthesis of valuable products that are not accessible through existing CO2 utilisation methodologies. PhD and post-doctoral positions to work on development of both stoichiometric and catalytic variants of this methodology are presently available.
2. Development of Environmentally Benign Replacements for Hazardous Standard Organic Reagents: Many of the reagents and solvents used in organic chemistry are harmful to the environment and may be toxic and/or carcinogenic. This project aims to develop methods for activating environmentally benign, stable organic chemicals (e.g. alcohols, aldehydes) to achieve the same outcomes as with standard hazardous reagents (alkyl halides and other alkylating agents, acyl halides). Strategies to achieve the ultimate goal of rendering these transformations catalytic are under development in our lab.
3. Development of Novel Means of Understanding Activation Barriers and Selectivities in Reactions of Ambident Nucleophiles: Reactions of ambident nucleophiles and electrophiles are extremely prevalent at all levels of organic synthesis. However, the factors that control selectivity between the reactive sites of an ambident reactant (i.e. which of the sites undergoes a given reaction more favourably) evade simple classification. By far the most popular method for rationalising the selectivities in reactions of ambident reactants makes use of the principle of hard and soft acids and bases (the “HSAB principle”). Although this rationale is pervasive in any discussion on ambident reactivity, there exists a major problem with its application: the HSAB principle has been shown to predict the wrong product in almost 50% of all known reactions of ambident nucleophiles!  Therefore, the HSAB principle cannot be providing the true explanation for the observed selectivities in reactions of ambident nucleophiles in which the expected outcome (based on HSAB theory) does match the experimental outcome. In order that this incorrect rationale ceases to be employed in research publications and taught in undergraduate chemistry courses, it is imperative that the true reasons underlying the selectivities observed in reactions of ambident reactants are uncovered. In this project, a novel means of rationalising the outcomes of reactions of ambident nucleophiles and electrophiles is under development. This rationale will enable development of new insights on the nature of activation barriers for chemical reactions in general, and will facilitate the development of new linear free energy relationships.
I also maintain interests in the following areas: Predicting and modelling rates of chemical reactions, development of quantitative Lewis basicity scales, applications of 15N NMR spectroscopy, spectroscopic observation of reactive intermediates, the Wittig reaction, and the theory of chemical bonding.
- See NASA website: https://climate.nasa.gov/causes/
- IPCC, 2014: Climate Change 2014: Synthesis Report. Contribution of Working Groups I, II and III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Core Writing Team, R.K. Pachauri and L.A. Meyer (eds.)]. IPCC, Geneva, Switzerland, 151 pp. – available at https://www.ipcc.ch/report/ar5/syr/.
- Yu, B.; Diao, Z.-F.; Guo, C.-X.; He, L.-N. J. CO2 Util. 2013, 1, 60.
- Lang, X.-D.; He, X.; Li, Z.-M.; He, L.-N. Curr. Opin. Green Sustain. Chem. 2017, 7, 31.
- Selected recent examples: (a) Biswas, A.; Neudörfl, J.-M.; Schlörer, N. E.; Berkessel, A. & co-workers; Angew. Chem. Int. Ed. 2021, 60, 4507; (b) McLaughlin, C.; Slawin, A. M. Z.; Smith, A. D. Angew. Chem. Int. Ed. 2019, 58, 15111.
- e.g. Clayden, J.; Greeves, N.; Warren, S. Organic Chemistry, 2nd edition; Oxford University Press: New York; 2012, p. 355–357.
- Selected recent example: Maiti, S.; Mal, P. J. Org. Chem. 2018, 83, 1340.
- Mayr, H.; Breugst, M.; Ofial, A. R. Angew. Chem. Int. Ed. 2011, 29, 6470.
- The new rationale will develop upon the following: Sheehy, K. J.; Bateman, L. M.; Flosbach, N. T.; Breugst, M.; Byrne, P. A. Chem. Sci. 2020, 11, 9630.
|Start Date||End Date||Award|
|Carbon Dioxide Utilisation for Construction of Non-Natural Amino Acids as Precursors to Novel Peptides and Responsive Biomaterials.||Irish Research Council||01-SEP-21||31-AUG-25||€55,000.00|
|Simultaneous unprotected glycoside activation/deactivation route ("SUGAR") for streamlined carbohydrate synthesis.||Irish Research Council||01-OCT-18||30-MAR-22||€74,625.00|
|The Assymmetric Synthesis of Carboxyl-Containing Compounds, Including Unnatural Amino Acids, by Car Dioxide Utilisation.||Irish Research Council||01-SEP-19||31-DEC-23||€105,333.00|
|Simultaneous Activation & Transient Protection for Streamlined Carbohydrate Synthesis||Enterprise Irl||15-AUG-17||15-MAY-18||€7,962.00|
|12/RC/2275_2 SSPC3 Pharm5 Molecules 1 P Byrne||Science Foundation of Ireland||01-JUN-19||31-MAY-25||€137,946.00|
|"Cleaning up" assymetric dihydroxylation: environmentally benign routes to chiral vicinal diols using organocatalytic assymetric dihydroxylation of alkenes||Irish Research Council||26-NOV-18||25-NOV-20||€91,846.00|
|Science Foundation of Ireland||01-DEC-21||30-NOV-25||€596,823.00|
|A paradigm shift in regioselective substitutions: activation with simultaneous deactivation for streamlined construction of carbohydrate-based therapeutics.||Irish Research Council||01-OCT-18||31-JUL-23||€102,125.00|
|Synthesis of currently inaccessible carboxyl-containing compounds by phosphonium ylide-mediated carbon dioxide activation and utilisation.||Irish Research Council||01-OCT-18||31-MAR-23||€102,125.00|
|Research Enablement Grant.||Foundation Funded Research||01-SEP-21||31-DEC-22||€11,670.00|
|A general, green method for organocatalytic Asymmetric Alkylation||Irish Research Council||01-JAN-22||31-DEC-25||€110,000.00|
Peer Reviewed Journals
|(2021)||'Nucleophilicities and Nucleofugalities of Thio- and Selenoethers' |
B. Maji, X.-H. Duan, P. M. Jüstel, P. A. Byrne, A. R. Ofial, H. Mayr (2021) 'Nucleophilicities and Nucleofugalities of Thio- and Selenoethers'. Chemistry - A European Journal, 27 [DOI] [Full Text] [Details]
|(2020)||'Identification of N‐ or O‐Alkylation of Aromatic Nitrogen Heterocycles and N‐Oxides Using 1H–15N HMBC NMR Spectroscopy' |
Kevin J. Sheehy, Lorraine M. Bateman, Niko T. Flosbach, Martin Breugst, Peter A. Byrne (2020) 'Identification of N‐ or O‐Alkylation of Aromatic Nitrogen Heterocycles and N‐Oxides Using 1H–15N HMBC NMR Spectroscopy'. European Journal of Organic Chemistry, :3270-3281 [DOI] [Full Text] [Details]
|(2020)||'Competition Between N and O: Use of Diazine N-Oxides as a Test Case for the Marcus Theory Rationale for Ambident Reactivity' |
Kevin Sheehy, Lorraine M Bateman, Niko T Flosbach, Martin Breugst and Peter Byrne (2020) 'Competition Between N and O: Use of Diazine N-Oxides as a Test Case for the Marcus Theory Rationale for Ambident Reactivity'. Chemical Science, [DOI] [Full Text] [Details]
|(2020)||'Synthesis of a Diaryliodonium Salt and Its Use in the Direct Arylation of Indole: A Two-Step Experiment for the Organic Teaching Laboratory' |
Aisling M. Prendergast, Rachel Shanahan, Aobha Hickey, Francis Harrington, David Schönbauer, Peter A. Byrne, Michael Schnürch, Gerard P. McGlacken (2020) 'Synthesis of a Diaryliodonium Salt and Its Use in the Direct Arylation of Indole: A Two-Step Experiment for the Organic Teaching Laboratory'. Journal Of Chemical Education, 97 :200-206 [DOI] [Full Text] [Details]
|(2017)||'Why are Vinyl Cations Sluggish Electrophiles?' |
P. A. Byrne, S. Kobayashi, E.-U. Würthwein, J. Ammer, H. Mayr (2017) 'Why are Vinyl Cations Sluggish Electrophiles?'. Journal of the American Chemical Society, 139 [DOI] [Full Text] [Details]
|(2016)||'Ambident Reactivity of Acetyl- and Formyl-Stabilized Phosphonium Ylides' |
P. A. Byrne, K. Karaghiosoff, H. Mayr (2016) 'Ambident Reactivity of Acetyl- and Formyl-Stabilized Phosphonium Ylides'. Journal of the American Chemical Society, 138 [DOI] [Full Text] [Details]
|(2016)||'The Mechanism of Phosphonium Ylide Alcoholysis and Hydrolysis: Concerted Addition of the O-H Bond Across the P=C Bond' |
Byrne, PA;Gilheany, DG (2016) 'The Mechanism of Phosphonium Ylide Alcoholysis and Hydrolysis: Concerted Addition of the O-H Bond Across the P=C Bond'. Chemistry - A European Journal, 22 :9140-9154 [DOI] [Full Text] [Details]
|(2016)||'Quantification of the nucleophilic reactivity of nicotine' |
Byrne, PA;Kobayashi, S;Breugst, M;Laub, H;Mayr, H (2016) 'Quantification of the nucleophilic reactivity of nicotine'. Journal Of Physical Organic Chemistry, 29 :759-767 [DOI] [Full Text] [Details]
|(2015)||'First ever observation of the intermediate of phosphonium salt and ylide hydrolysis: P-hydroxytetraorganophosphorane' |
Byrne, PA;Ortin, Y;Gilheany, DG (2015) 'First ever observation of the intermediate of phosphonium salt and ylide hydrolysis: P-hydroxytetraorganophosphorane'. Chemical Communications, 51 :1147-1150 [DOI] [Full Text] [Details]
|(2014)||'Investigations on the Operation of Stereochemical Drift in the Wittig Reaction by NMR and Variable-Temperature NMR Spectroscopy of Oxaphosphetane Intermediates and Their Quench Products' |
Byrne, PA;Muldoon, J;Ortin, Y;Muller-Bunz, H;Gilheany, DG (2014) 'Investigations on the Operation of Stereochemical Drift in the Wittig Reaction by NMR and Variable-Temperature NMR Spectroscopy of Oxaphosphetane Intermediates and Their Quench Products'. European Journal of Organic Chemistry, 2014 :86-98 [DOI] [Full Text] [Details]
|(2013)||'The Modern Interpretation of the Wittig Reaction Mechanism' |
P. A. Byrne, D. G. Gilheany (2013) 'The Modern Interpretation of the Wittig Reaction Mechanism'. Chemical Society Reviews, 42 [DOI] [Full Text] [Details]
|(2012)||'Unequivocal experimental evidence for a unified Li salt-free Wittig reaction mechanism for all phosphonium ylide types: Reactions with β-heteroatom substituted aldehydes are consistently selective for cis-oxaphosphetane derived products' |
P. A. Byrne, D. G. Gilheany (2012) 'Unequivocal experimental evidence for a unified Li salt-free Wittig reaction mechanism for all phosphonium ylide types: Reactions with β-heteroatom substituted aldehydes are consistently selective for cis-oxaphosphetane derived products'. Journal of the American Chemical Society, 134 [DOI] [Full Text] [Details]
|(2012)||'Anomalous Z-isomer content in Wittig reaction products from keto-stabilised ylides with ortho-heteroatom substituted benzaldehydes' |
P. A. Byrne, L. J. Higham, P. McGovern, D. G. Gilheany (2012) 'Anomalous Z-isomer content in Wittig reaction products from keto-stabilised ylides with ortho-heteroatom substituted benzaldehydes'. Tetrahedron Letters, 53 [DOI] [Full Text] [Details]
|(2012)||'A convenient and mild chromatography-free method for the purification of the products of Wittig and Appel reactions' |
P. A. Byrne, K. V. Rajendren, J. Muldoon, D. G. Gilheany (2012) 'A convenient and mild chromatography-free method for the purification of the products of Wittig and Appel reactions'. Organic and Biomolecular Chemistry, 10 :3531-3537 [DOI] [Full Text] [Details]
|(2012)||Investigation of Reactions Involving Pentacoordinate Intermediates: The Mechanism of the Wittig Reaction. |
P. A. Byrne (2012) Investigation of Reactions Involving Pentacoordinate Intermediates: The Mechanism of the Wittig Reaction. Germany: Springer. [DOI] [Details]
Honours and Awards
|2012||Springer Thesis Prize||Springer|
|2007||Hugh Ryan medal||University College Dublin School of Chemistry|
|2007||IRCSET Postgraduate Funding||Irish Research Council|
|2014||Alexander von Humboldt Postdoctoral Fellowship||Alexander von Humboldt Foundation|
|Association||Function||From / To|
|Royal Society of Chemistry||Associate Member||01-JUN-17 / 31-DEC-22|
|Committee||Function||From / To|
|School of Chemistry Teaching & Learning Committee||Committee Member, Representative for CPC2 Degree Programme||2021 /|
|College of SEFS Health & Safety Committee||Committee Member||2020 /|
|School of Chemistry Safety Advisory Committee||Chairperson||2019 /|
|School of Chemistry Staff-Student Committee||Chairperson||2017 / 2019|
|Research & Graduate Studies Committee||Committee Member||/|
I participated in the School of Chemistry tent at this event, demonstrating interactive experiments to members of the public and explaining the underlying chemistry involved in a "user-friendly" manner.
I participated at the stand of the SSPC (SFI Research Centre for Pharmaceuticals) at this event, demonstrating interactive experiments to members of the public and explaining the underlying chemistry involved in a "user-friendly" manner.
I made a presentation (in the Poor Relation pub) to members of the public on aspects of my research, explaining what is involved in an accessible and easily understandable way.
Primary and secondary school students come to a lab in UCC and engage in various chemical laboratory activities, including conducting a "forensic investigation". I assist in the running of this event.
|Journal||Role||To / From|
|Angewandte Chemie International Edition||Peer Reviewer||-|
|Nature Communications||Peer Reviewer||-|
|Chemical Communications||Peer Reviewer||-|
|Chemical Physics Letters||Peer Reviewer||-|
|Journal Of Organic Chemistry||Peer Reviewer||-|
|Journal Of Chemical Research||Peer Reviewer||-|
|Organic Letters||Peer Reviewer||-|
I am a Funded Investigator in the SSPC, the SFI Research Centre for Pharmaceuticals, which is a collaborative body that includes most of the world’s leading pharmaceutical companies as members. Through this, and also engaging in site visits to pharmaceutical plants as part of the CPC B.Sc. programme, I have developed connections with multiple pharmaceutical companies – Pfizer, Janssen, Lilly, and MSD (Merck, Sharp & Dohme). My research group and I make regular presentations to these companies and the wider SSPC community.
I organised an international conference in UCC in July 2021 – the Royal Society of Chemistry Organic Division Ireland conference (https://www.rsc.org/events/detail/47500/rsc-organic-division-ireland-regional-meeting-2021)
Teaching InterestsSpectroscopic techniques, with particular application to the determination of rate constants and equilibrium constants - including NMR, IR, MS, UV-Vis (including laser flash photolysis and stopped flow techniques).
Physical Organic Chemistry
Molecular orbital symmetry (use of Walsh diagrams)
Synthetic organic chemistry
Current Postgraduate Students
|Cregan Aidan Christopher||Doctoral Degree|
|Curran Dara||Doctoral Degree|
|Lynch Rachel Emily||Doctoral Degree|
|Ryan David||Doctoral Degree|
|Szydlo Marcin||Doctoral Degree|
|Michel Marie Clara||Doctoral Degree|
|Furlong Emma||Doctoral Degree|
|Lowry Amy Bridget||Doctoral Degree|
|Sheehy Kevin John||Doctoral Degree|
|O Donnell Joshua||Doctoral Degree|
|Dr Lorraine Bateman||UCC||IRELAND|
|Dr Ger McGlacken||UCC||IRELAND|
|Name||Organisation / Institute||Country|
|Prof. Turlough Downes||DCU||IRELAND|
|Dr Lidia Tajber||Trinity College Dublin||IRELAND|
|Dr Aniello Palma||University of Kent||UNITED KINGDOM|
|Prof. Martin Breugst||TU Chemnitz||GERMANY|