Novel Concepts for Iron- and Manganese-catalyzed Homogenous Redox Transformations
Produktform: Buch
Transition metal catalysis plays a crucial role in the development of new chemical transformations,
which can be broadly applied in organic synthesis, medicinal chemistry, synthesis of biologically
relevant molecules, pharmaceuticals and other related fields. In recent years, the need for application of
sustainable methods is significantly growing due to the necessity of waste-free transformations.[1-2]
Plenty of industrially run processes still apply classical procedures, which often lead to production of
tons of waste as a consequence of multistep synthesis. Thus, development of novel catalytic systems
which would afford complex molecular structures via straightforward processes is still desired. Hence,
metal-catalyzed transformations play a crucial role in the development of new synthetic strategies, as
they can easily lead to the reduction of synthetic steps and, ipso facto, reduction of waste leading to
atom-economic transformations.
Application of transition metals particularly in homogenous catalysis was initiated by industrial
processes such as carbonylation of alkenes and alkynes by metal carbonyls, production of polyethylene
and polypropylene by the Ziegler-Natta catalysts or conversion of ethylene into acetaldehyde in the
Wacker’s process. This breakthrough inspired investigation of other synthetic reactions, which could be
catalyzed by transition metals.[3] Soon after, the field was dominated by application of catalysts
containing precious-metal centers leading to the facile synthesis of higher molecules. Significant role of
transition metals in chemistry was highlighted by Nobel prizes in 2001 (K. B. Sharpless, W. S. Knowles,
R. Noyori) for metal-catalyzed enantioselective hydrogenation and oxidation reactions, in 2005
(R. Schrock, R. Grubbs, Y. Chauvin) for application of transition metals in metathesis and in 2010
(R. F. Heck, A. Suzuki, E. Negishi) for application of Pd-based systems in cross-coupling reactions,
which with enormous impact modernized organic synthesis in research laboratories and in industry.
However, the application of late and noble metal catalytic systems exhibits crucial drawbacks. Noble
metals are expensive, due to their low abundance in the earth crust (Figure 1)[4] and related challenges
in their extraction. Moreover, they are toxic and lead to formation of toxic waste.
Taking into account the huge impact of catalysis nowadays and how it can influence our life and
environment, modern chemical society focuses on finding more economically and environmentally
friendly methods. As an alternative, implementation of base metal catalysis gained a lot of attention as
it can lead to most cost-effective and more environmentally friendly protocols. Moreover, base metals
can demonstrate similar reactivity as noble metals or exhibit new features, leading to other interesting
transformations.weiterlesen