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chemistry. In this context, transition metal-catalysed C–H activation reactions further have been arisen as a potent green chemistry approach recently. This is because
such conversions offer several advantages like it avoids the necessity of prior efforts
for activation of the starting substrates.
1.1 C–H Activation: A Green and Economical
Synthetic Protocol
Depletable resources namely crude oil and natural gas are the source of most of
organic molecules and materials [14, 15]. Utilization of such feedstocks to convert
into another useful chemicals is the great opportunity as well as challenge for the
chemists. This involves cleavage and construction of another C–C bonds and converting C–H bonds into desired functional groups. This objective has been achieved
by using most traditional pathways like initial C–H bond functionalization such as
radical functionalization [16, 17] or partial aerobic oxidations [18]. Such functionalization is then succeeded by an alterable order of steps to provide anticipated
functional groups or C–C bonds in order to synthesize the targeted frameworks.
This widely significant approach is referred as functional group interconversion
strategy [19, 20].
Although functional group interconversion strategy has been established as a
vital tool in organic transformations, it generally leads to highly wasteful methodologies as it requires multiple steps from unfunctionalized starting substrates to
functionalized products, hence suffer from limitations. In this fashion, serious environmental restrictions are being faced by fine chemical and pharmaceutical industries and hence they are attempting to diminish or exclude waste, and also harmful
and tedious methods. In this regard, a modern chemistry has paid considerable attention towards the advancement of ideal synthetic methodologies which are potential,
cost-effective and ecologically benign in order to synthesize complex moieties.
From the viewpoint of green chemistry, highly efficient and step economic
metal-catalysed straight activation of C–H bonds has potential to replace traditional
organic transformations in order to synthesize complex organic scaffolds. In contrast to conventional methodologies for such kind of bond construction, activation
of C–H bond avoids the initial functionalization (for instance, halogenation or borylation) of the target molecules that drops number of steps. Ideally, multiple step
synthesis could thus be modulated into single-step synthesis permitting straight
approach to anticipated frameworks, thereby decreasing the quantity of unwanted
refuse of multistep transformations. Accordingly, through the enhanced step and
atom economy, synthetic ‘shortcuts’ could be attained [21, 22]. Therefore, transition metal-catalysed C–H bond activation claims to be an ideal and influential
approach to construct bonds and establish functional groups in a straight manner.
This is frequently believed as a ‘Holy Grail’ in organic synthesis and has been
widely studied over the past decades, leading to substantial progress in the area
[23, 24].
Insights into Sustainable C–H Bond Activation
chemistry. In this context, transition metal-catalysed C–H activation reactions further have been arisen as a potent green chemistry approach recently. This is because
such conversions offer several advantages like it avoids the necessity of prior efforts
for activation of the starting substrates.
1.1 C–H Activation: A Green and Economical
Synthetic Protocol
Depletable resources namely crude oil and natural gas are the source of most of
organic molecules and materials [14, 15]. Utilization of such feedstocks to convert
into another useful chemicals is the great opportunity as well as challenge for the
chemists. This involves cleavage and construction of another C–C bonds and converting C–H bonds into desired functional groups. This objective has been achieved
by using most traditional pathways like initial C–H bond functionalization such as
radical functionalization [16, 17] or partial aerobic oxidations [18]. Such functionalization is then succeeded by an alterable order of steps to provide anticipated
functional groups or C–C bonds in order to synthesize the targeted frameworks.
This widely significant approach is referred as functional group interconversion
strategy [19, 20].
Although functional group interconversion strategy has been established as a
vital tool in organic transformations, it generally leads to highly wasteful methodologies as it requires multiple steps from unfunctionalized starting substrates to
functionalized products, hence suffer from limitations. In this fashion, serious environmental restrictions are being faced by fine chemical and pharmaceutical industries and hence they are attempting to diminish or exclude waste, and also harmful
and tedious methods. In this regard, a modern chemistry has paid considerable attention towards the advancement of ideal synthetic methodologies which are potential,
cost-effective and ecologically benign in order to synthesize complex moieties.
From the viewpoint of green chemistry, highly efficient and step economic
metal-catalysed straight activation of C–H bonds has potential to replace traditional
organic transformations in order to synthesize complex organic scaffolds. In contrast to conventional methodologies for such kind of bond construction, activation
of C–H bond avoids the initial functionalization (for instance, halogenation or borylation) of the target molecules that drops number of steps. Ideally, multiple step
synthesis could thus be modulated into single-step synthesis permitting straight
approach to anticipated frameworks, thereby decreasing the quantity of unwanted
refuse of multistep transformations. Accordingly, through the enhanced step and
atom economy, synthetic ‘shortcuts’ could be attained [21, 22]. Therefore, transition metal-catalysed C–H bond activation claims to be an ideal and influential
approach to construct bonds and establish functional groups in a straight manner.
This is frequently believed as a ‘Holy Grail’ in organic synthesis and has been
widely studied over the past decades, leading to substantial progress in the area
[23, 24].
Insights into Sustainable C–H Bond Activation