phase test validity and does not determine whether the active species is mononuclear
species or small metal nanoparticles (i.e. has the ability to penetrate the resin). For
example, Fagnou et al. showed that the pore size of a Wang resin is sufficient to
allow seeding and propagation of small nanoparticles [68].
5 Case Studies Involving Supported
Nanoparticle-Catalysed C–H Bond Functionalising
Reactions
C–H bond functionalisation by heterogeneous catalysis is a currently burgeoning
field, and there is a wealth of diversity in reactivity being uncovered. With a view to
facilitate the reader to gain a strong foothold on the field, six case studies of
published examples of representative, cutting-edge heterogeneously catalysed C–H
bond functionalisation reactions have been specially selected and will be discussed
in detail herein. In each case study, emphasis will be placed on (1) exhibiting the
variety of reactivity of such systems and thus the broadness of their synthetic utility;
(2) detailing what is known about the mechanism of reactivity, with emphasis on
what is known about active catalyst speciation in order to prime the reader for
reactivity trends, where possible the reader’s attention will be drawn to the variety
of techniques that can be employed to characterise the catalyst and probe its mode of
activity; and (3) detailing and critiquing the overall greenness of each process
(e.g. catalyst recyclability, solvents and reagents, overall efficiency, etc.). With
each case study taken together, we aim to illustrate the power and diversity of
heterogeneous C–H functionalisation chemistry.
We have found that most examples of supported heterogeneous catalysts for use
in C–H functionalisation fall under four broad categories:
1. Metal–metal frameworks
2. Metal–organic frameworks
3. Silica and alumina-based frameworks
4. Carbon-based frameworks (including Pd/C)
5.1 Case Study I) Reusable, Site-Selective Direct C–H
Arylation of Heteroarenes Enabled by CuO/Fe 3 O 4
Nanoparticles
In an example of a metal–metal framework, Glorius et al. employed CuO
nanoparticles supported on Fe 3 O 4 (magnetite) as a catalyst in direct arylations of a
variety of heterocycles [69]. A fascinating and rigorous mechanistic study was
carried out, which, taken together, pointed towards a soluble (homogeneous)
186
I. J. S. Fairlamb and N. W. J. Scott
species or small metal nanoparticles (i.e. has the ability to penetrate the resin). For
example, Fagnou et al. showed that the pore size of a Wang resin is sufficient to
allow seeding and propagation of small nanoparticles [68].
5 Case Studies Involving Supported
Nanoparticle-Catalysed C–H Bond Functionalising
Reactions
C–H bond functionalisation by heterogeneous catalysis is a currently burgeoning
field, and there is a wealth of diversity in reactivity being uncovered. With a view to
facilitate the reader to gain a strong foothold on the field, six case studies of
published examples of representative, cutting-edge heterogeneously catalysed C–H
bond functionalisation reactions have been specially selected and will be discussed
in detail herein. In each case study, emphasis will be placed on (1) exhibiting the
variety of reactivity of such systems and thus the broadness of their synthetic utility;
(2) detailing what is known about the mechanism of reactivity, with emphasis on
what is known about active catalyst speciation in order to prime the reader for
reactivity trends, where possible the reader’s attention will be drawn to the variety
of techniques that can be employed to characterise the catalyst and probe its mode of
activity; and (3) detailing and critiquing the overall greenness of each process
(e.g. catalyst recyclability, solvents and reagents, overall efficiency, etc.). With
each case study taken together, we aim to illustrate the power and diversity of
heterogeneous C–H functionalisation chemistry.
We have found that most examples of supported heterogeneous catalysts for use
in C–H functionalisation fall under four broad categories:
1. Metal–metal frameworks
2. Metal–organic frameworks
3. Silica and alumina-based frameworks
4. Carbon-based frameworks (including Pd/C)
5.1 Case Study I) Reusable, Site-Selective Direct C–H
Arylation of Heteroarenes Enabled by CuO/Fe 3 O 4
Nanoparticles
In an example of a metal–metal framework, Glorius et al. employed CuO
nanoparticles supported on Fe 3 O 4 (magnetite) as a catalyst in direct arylations of a
variety of heterocycles [69]. A fascinating and rigorous mechanistic study was
carried out, which, taken together, pointed towards a soluble (homogeneous)
186
I. J. S. Fairlamb and N. W. J. Scott