Exciting developments associated with mixed metal NPs and their applications
that highlight synergistic effects of synthetic value offer a glimpse of what is likely
to be an increasingly important direction for catalysis in the near future.
Keywords Catalysis · Nanoparticles · Synergistic effects between metals ·
Transition metals
1 Introduction
Metal nanoparticle technology applied to organic synthesis continues to blossom.
New materials for catalysis are being introduced on a regular basis, while methods
for their analyses have become increasingly sophisticated, offering insights that
have led to many of these advances. Technically, even in cases where these materials
are quite small, including metal clusters, metal nanoparticles (NPs), and even species
containing single atoms, they are all categorized within the area of heterogeneous
catalysis. A timely and extensive review by Liu and Corma in 2018 highlighted
the important factors that can influence metal catalysts of these types, drawing
attention to parameters such as size and shape, among several others (e.g., metal
support, their chemical make-up, the influence of additives such as other metals, etc.)
[1]. At stake, of course, are the resulting key issues of reactivity and selectivity and,
ultimately, synthetic utility. Hence, this review focuses on not only the development
of new NPs but also the synthetic applications that have appeared over the past
decade, discussed according to metal.
2 Palladium
Palladium occupies a unique position among transition metals in the field of
catalysis. Although a costly precious metal, it remains world-renowned for its ability
to catalyze formation of new C-C bonds, such as Heck cross-coupling reactions to
form new substituted olefins; the Suzuki-Miyaura, Kumada, and Stille couplings,
which can afford, e.g., new biaryls; Negishi couplings that facilitate introduction
of alkyl groups onto carbon sp
2 centers; and Sonogashira reactions which can afford
substituted alkynes [2–8]. Moreover, gases such as CO and CO 2 can also be used in
tandem with palladium catalysts to generate carbonyl-containing products [9, 10].
Palladium is also the “go-to” metal in many hydrogenation reactions [11]. The
products of these numerous types of reactions oftentimes contain structural motifs
present in natural products, polymers, and a wide array of pharmaceuticals and
other targets within the fine chemical industry [12].
78
M. Cortes-Clerget et al.
that highlight synergistic effects of synthetic value offer a glimpse of what is likely
to be an increasingly important direction for catalysis in the near future.
Keywords Catalysis · Nanoparticles · Synergistic effects between metals ·
Transition metals
1 Introduction
Metal nanoparticle technology applied to organic synthesis continues to blossom.
New materials for catalysis are being introduced on a regular basis, while methods
for their analyses have become increasingly sophisticated, offering insights that
have led to many of these advances. Technically, even in cases where these materials
are quite small, including metal clusters, metal nanoparticles (NPs), and even species
containing single atoms, they are all categorized within the area of heterogeneous
catalysis. A timely and extensive review by Liu and Corma in 2018 highlighted
the important factors that can influence metal catalysts of these types, drawing
attention to parameters such as size and shape, among several others (e.g., metal
support, their chemical make-up, the influence of additives such as other metals, etc.)
[1]. At stake, of course, are the resulting key issues of reactivity and selectivity and,
ultimately, synthetic utility. Hence, this review focuses on not only the development
of new NPs but also the synthetic applications that have appeared over the past
decade, discussed according to metal.
2 Palladium
Palladium occupies a unique position among transition metals in the field of
catalysis. Although a costly precious metal, it remains world-renowned for its ability
to catalyze formation of new C-C bonds, such as Heck cross-coupling reactions to
form new substituted olefins; the Suzuki-Miyaura, Kumada, and Stille couplings,
which can afford, e.g., new biaryls; Negishi couplings that facilitate introduction
of alkyl groups onto carbon sp
2 centers; and Sonogashira reactions which can afford
substituted alkynes [2–8]. Moreover, gases such as CO and CO 2 can also be used in
tandem with palladium catalysts to generate carbonyl-containing products [9, 10].
Palladium is also the “go-to” metal in many hydrogenation reactions [11]. The
products of these numerous types of reactions oftentimes contain structural motifs
present in natural products, polymers, and a wide array of pharmaceuticals and
other targets within the fine chemical industry [12].
78
M. Cortes-Clerget et al.