School of Natural and Environmental Sciences

Staff Profile

Dr Simon Doherty

Senior Lecturer

Background

Introduction

Dr Simon Doherty is a senior lecturer in Organometallic Chemistry and Catalysis and Director of NUCAT. He was awarded first class Hons. in Chemistry in 1987 and a PhD in 1990 for a thesis Coordination and Cluster Compounds of Primary Phosphines, both from University College London. After working as a postdoctoral researcher with Professor Arthur J. Carty at Waterloo, Canada, investigating small molecule activation and skeletal transformations of phosphinidine stabilized clusters and the reactivity of hydrocarbyl ligands on bimetallic phosphido-bridged complexes, he moved to Bloomington Indiana to work with Professor Malcolm Chisholm (FRS), preparing alkyl and alkoxide supported transition metal alkylidynes, nitrides and oxides and studying their MOCVD characteristics.

Previous Positions

1994-1995 Lecturer in Inorganic Chemistry University of Wales, Swansea
1995-2001 Senior Lecturer in Inorganic Chemistry, University of Newcastle
2001-2004 Reader in Inorganic Chemistry, Queen’s University of Belfast
2004-present Senior Lecturer in Inorganic Chemistry, University of Newcastle

Doherty has published 100 research papers, written invited review articles, 2 invited Nature Protocols and contributed to several books, most recently a chapter entitled Homogeneous Catalysis in Ionic Liquids in the RSC Catalysis Series, Catalysis in Ionic Liquids: From Catalyst Synthesis to Applications.

 

Research

 

DOHERTY@NEWCASTLE UNIVERSITY CATALYSIS (NUCAT)

1. Phosphine Synthesis & Catalysis

The Doherty Group is firmly established as the principal and leading phosphine synthesis and catalysis research group at Newcastle University. The unifying theme in the Groups Phosphine Synthesis Team is the development of innovative synthetic methodology directed towards novel and architecturally distinct chiral and achiral mono- and bidentate phosphorus-based ligands and exploring their applications in platinum group metal catalysis. Over the past decade the group has assembled the NUCAT ligand kit which comprises a range of mono- and bidentate phosphines, these include:

  1. NUPHOS diphosphines via zirconium-mediated reductive coupling of alkynes 
  2. NU-BIPHEP diphosphines via rhodium-catalyzed [2 2 2] cycloaddition
  3. KITPHOS monophosphines via Diels-Alder cycloaddition of alkynylphosphine oxides
  4. CATPHOS diphosphines via double Diels-Alder cycloaddition to diynes
  5. NU-biaryl diphosphines via sequential Diels-Alder cycloaddition-extrusion
  6. NU-biaryl monophosphines via cross coupling of phosphonate-substituted aryl and naphthylboronate esters.

The most recent addition to the NUCAT ligand kit is the bulky electron-rich NU-dihydro-KITPHOS class of monophosphine which form highly efficient catalysts for the Suzuki-Miyaura cross coupling between a host of electronically diverse aryl chlorides and boronic acids.

2. Polymer Immobilised Ionic Liquid Phase (PIILP) Catalysis

A team of researchers is exploring the use of polymer immobilised ionic liquids (PIILs) to improve existing catalytic transformations, for instance, enhancing reactions rate, improving catalyst lifetime, achieving multiple recycles and engineering continuous processes.  

Recent Developments

(a) POM-based PIILP Oxidation Catalysis (POM@PIILP)

A novel peroxometalate-based Polymer Immobilised Ionic Liquid Phase (PIILP) catalyst has been developed for the epoxidation of alkenes and allylic alcohols; the system can be recycled and reused up to 5 times with only a minor reduction in performance on successive cycles. The catalysts are prepared by combining a novel cation-decorated co-polymer, generated via Ring Opening Metathesis Polymerization (ROMP), with an oxidation active polyoxometalate; the resulting catalytic material is a free flowing, robust, air-stable solid. 

The concept of PIILP catalysis is currently being used to develop continuous flow systems for oxidations, carbonylations and C-C bond formation. To this end, our peroxometalate based PIILP catalyst has shown a marked enhancement in rate and selectivity for the oxidation of sulfides in continuous flow compared with conventional batch conditions.

(b) Asymmetric PIILP Catalysis (CuBox@PIILP)

Lewis acid copper-bis(oxazoline) based PIILP catalysts also show a marked enhancement in rate and selectivity, compared with their  homogeneous counterparts in conventional organic solvents, across a host of asymmetric C-C bond forming reactions.

(c) Nanoparticle-based PIILP Catalysis (NP@PIILP)

The team is also exploring how the polymer microstructure and charge density affects the size, distribution and morphology of gold and palladium nanoparticles and to this end we have shown that heteroatom donor modified PdNP@PIILP  are highly efficient systems for Suzuki-Miyaura cross coupling,  as well as the dehydrogenation of formic acid. In their most recent developmentm the group has shown that  PdNP@PIILP systems are highly selective (87%) for hydrogenation of the C=C bond in a range of alpha,beta-unsaturated aldehydes and ketones and remarkably active and highly selective catalysts for the reduction of aromatic nitro compounds to N-hydroxylamines, azoyarenes and anilines while AuNP@PIILP is high selective for the partial reduction of nitroaenes to N-arylhydroxylamines and azoxyarenes. The results of our work have recently been disclosed in Green Chem. (2017), Catal. Sci. & Technol. (2018), Adv. Synth. Catal. (2018), Adv. Synth. Catal. (2018) and ACS Catalysis (2019 in press).

 

3. Phosphinoboration

Westcott and Doherty have recently teamed up in a collaboration to develop new phosphinoboronate esters for  the synchronous formation of P-C and B-C/B-heteroatom bonds i.e. phosphinoboration. Reagents of the type R2P-B(OR)2 (R = Ph, Cy, tert-butyl, OR = pinacol, catechol) react readily with aldehydes, ketones, imines and enones to give the corresponding 1,2-addition products. The reagents also undergo metal catalysed regioselective addition to C-C multiple bonds in alkynes and allenes. Studies are currently under way to explore the scope of this transformation, extend the range of substrates, develop the fundamental coordination chemistry relevant to catalysis and to understand the mechanism. Results of preliminary studies have recently been accepted for publication in Angewandte Chemie (December 2014).  

 

Collaborators

Dr J. G. Knight (Newcastle), Professor S. A. Westcott (Mount Allison, Canada), Professor Ian Fiarlamb (University of York), Professor P. A. Christensen (Newcastle), Dr M. A. Carroll (Newcastle), Dr Richard A Bourne (Leeds),  Dr Tom Chamberlain (Leeds), Professor Christopher Hardacre (Manchester),

 

 

 

 

Publications