Top Organomet Chem (2020) 66: 171–206
DOI: 10.1007/3418_2020_41
# Springer Nature Switzerland AG 2020
Published online: 4 August 2020
Pd Nanoparticles in C–H Activation
and Cross-coupling Catalysis
Ian James Stewart Fairlamb and Neil Walter James Scott
Contents
1 Introduction: Background to Cross-Coupling and C–H Bond Activation and
Functionalisation Chemistry . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . .. . . . . . . . . . . . 172
2 Evidence for Catalytically Active Heterogeneous Species in Classic Cross-Coupling
Processes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174
3 The Case for Quasi-Heterogeneous Catalysis in C–H Activation: Importance of Reaction
Conditions in the Evolution of Heterogeneous Species from Homogeneous Sources . . . . 180
4 A Practical Guide for Confirming Heterogeneity in Cross-Coupling Reactions . . . . . . . . . . . 184
5 Case Studies Involving Supported Nanoparticle-Catalysed C–H Bond Functionalising
Reactions . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . 186
5.1 Case Study I) Reusable, Site-Selective Direct C–H Arylation of Heteroarenes
Enabled by CuO/Fe 3 O 4 Nanoparticles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186
5.2 Case Study II) Direct C–H Acetoxylations, Methoxylations, Halogenations
and Arylations of Heterocycles Catalysed by Pd
II
/MWCNT Carbon Nanotubes . . . 189
5.3 Case Study III) Pd/C-Catalysed C–H Alkenylations in Continuous Flow, Using
γ-Valerolactone as a Green Reaction Medium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191
5.4 Case Study IV) A Pd–Polypyrrole Nanocomposite-Catalyst for Direct C–H
Activation of Heteroaromatics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192
5.5 Case Study V) 2-Arylpyridine Coupling with Alkylbenzene PdNPs on a γ-Al 2 O 3
Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195
5.6 Case Study VI) Development and Optimisation of Conditions for Pd/C-Catalysed
Site-Selective C–H Activation Reactions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . 197
6 Future Perspectives and Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200
Abstract This chapter reviews the state of the art in the use of nanoparticles in
cross-coupling catalysis, with a focus on C—H activation chemistry. Current understanding of the mechanistic role of heterogeneous catalyst sources as applied to
classic cross-coupling process is discussed. Understanding of the factors that influence speciation of catalysts under conditions commonly employed in C–H activation/functionalisation chemistry is highlighted. An overview of the tests that an
I. J. S. Fairlamb (*) and N. W. J. Scott
Department of Chemistry, University of York, York, UK
e-mail: ian.fairlamb@york.ac.uk; nwjs500@york.ac.uk
DOI: 10.1007/3418_2020_41
# Springer Nature Switzerland AG 2020
Published online: 4 August 2020
Pd Nanoparticles in C–H Activation
and Cross-coupling Catalysis
Ian James Stewart Fairlamb and Neil Walter James Scott
Contents
1 Introduction: Background to Cross-Coupling and C–H Bond Activation and
Functionalisation Chemistry . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . .. . . . . . . . . . . . 172
2 Evidence for Catalytically Active Heterogeneous Species in Classic Cross-Coupling
Processes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174
3 The Case for Quasi-Heterogeneous Catalysis in C–H Activation: Importance of Reaction
Conditions in the Evolution of Heterogeneous Species from Homogeneous Sources . . . . 180
4 A Practical Guide for Confirming Heterogeneity in Cross-Coupling Reactions . . . . . . . . . . . 184
5 Case Studies Involving Supported Nanoparticle-Catalysed C–H Bond Functionalising
Reactions . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . 186
5.1 Case Study I) Reusable, Site-Selective Direct C–H Arylation of Heteroarenes
Enabled by CuO/Fe 3 O 4 Nanoparticles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186
5.2 Case Study II) Direct C–H Acetoxylations, Methoxylations, Halogenations
and Arylations of Heterocycles Catalysed by Pd
II
/MWCNT Carbon Nanotubes . . . 189
5.3 Case Study III) Pd/C-Catalysed C–H Alkenylations in Continuous Flow, Using
γ-Valerolactone as a Green Reaction Medium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191
5.4 Case Study IV) A Pd–Polypyrrole Nanocomposite-Catalyst for Direct C–H
Activation of Heteroaromatics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192
5.5 Case Study V) 2-Arylpyridine Coupling with Alkylbenzene PdNPs on a γ-Al 2 O 3
Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195
5.6 Case Study VI) Development and Optimisation of Conditions for Pd/C-Catalysed
Site-Selective C–H Activation Reactions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . 197
6 Future Perspectives and Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200
Abstract This chapter reviews the state of the art in the use of nanoparticles in
cross-coupling catalysis, with a focus on C—H activation chemistry. Current understanding of the mechanistic role of heterogeneous catalyst sources as applied to
classic cross-coupling process is discussed. Understanding of the factors that influence speciation of catalysts under conditions commonly employed in C–H activation/functionalisation chemistry is highlighted. An overview of the tests that an
I. J. S. Fairlamb (*) and N. W. J. Scott
Department of Chemistry, University of York, York, UK
e-mail: ian.fairlamb@york.ac.uk; nwjs500@york.ac.uk