From Mechanisms in Homogeneous Metal Catalysis to Applications in Chemical Synthesis

Abstract

Man-made homogeneous catalysis with the aid of transition metal compounds looks back on a long history of almost one hundred years. Still, more detailed insight into the underlying mechanisms is warranted. The knowledge of how transition metals with their specific/characteristic properties, such as oxidations states, redox chemistry, spin states, kinetics, and coordination preference will contribute to these processes paving the way to optimize existing processes, and to finding new exciting organic, inorganic, and organometallic transformations and to broaden the substrate scope through catalyst design. This special issue collects very recent mechanistic insight from experimental, theoretical, and mixed experimental-theoretical approaches.At the very end of the 19th century, Alfred Werner established the basis of our modern understanding of (transition) metal complexes [1]. When Otto Roelen discovered and developed the hydroformylation reaction (or Oxo Process) in the late 1930s, probably the first milestone in homogeneous catalysis, serendipity played an important role [2,3]. A deeper understanding of the specific interactions of ligands and metals came only later with the development of binding concepts such as the ligand field theory and the molecular orbital theory, e.g., the Dewar-Chatt-Duncanson model, which was developed in the 1950s for the binding of olefins to transition metals [4]. Originally dedicated to the binding situation of the complex anion of the Zeise salt [PtCl 3 (ethene)] -, it soon became clear that homogeneously metal-catalyzed transformations of olefins can be described and understood using this concept [4][5][6][7]. Probably the most prominent examples of such olefin complexes are the Pd derivatives of the Zeise anion [PdCl 3 (olefin)] − , which were the pivotal species of today's technically most important organocatalytic process, the Wacker Process (or Wacker Oxidation), which was developed starting in the 1950s [7][8][9][10].About 80 years after Roelen's hydroformylation, on a list of recently identified "holy grails" in chemistry "perfect catalysis" is prominently in the top ten [11] and homogeneous transition metal catalysis provides the basis for many desired transformations, e.g., in C-H aminations, in site-selective bond activations, for the functionalization of alkanes or in oxidative couplings yielding complex target molecules. Even since the rise of "metal-free" organo-catalysis at the beginning of our millennium and its enormous impact on organic transformations, the meanwhile established "classical" (transition) metal mediated applications reside as solid pillars in the toolbox for chemical synthesis [12][13][14]. Recent Nobel Prizes in chemistry, i.e., 2010 to Richard F. Heck, Ei-ichi Negishi and Akira Suzuki, 2005 to Yves Chauvin, Robert H. Grubbs and Richard R. Schrock, as well as 2001 to William S. Knowles, Ryoji Noyori and K. Barry Sharpless [14,15] clearly highlight homogeneous transition metal catalysis as an outstanding discipline, crucial for various are...

Palladium-Catalyzed Asymmetric Allylic C–H Functionalization: Mechanism, Stereo- and Regioselectivities, and Synthetic Applications

“…The stereo- and regioselective bond formation enabled by transition metal catalysis has long been an ongoing challenge in organic synthetic chemistry . Highly enantioselective allylic C–H functionalization reactions enabled by chiral palladium catalysis can tolerate a wide range of nucleophiles and α-alkenes, providing a large family of optically active starting materials or building blocks applicable to the synthesis of natural products and biologically important unnatural molecules.…”

Theme Issue in Memory to Professor Jiro Tsuji (1927–2022)

“…Considering the keywords "catalysis" and "history", more than one thousand papers could be found (e.g., 1300 in the Web of Science on April 16, 2024). Interestingly, the special aspects on the development of catalysis research have been presented in respect not only to the different research fields of catalysis (e.g., organotextile catalysis [8], heterogeneous catalysis [9,10], homogeneous catalysis [11,12], electrocatalysis [13], single-atom catalysis [14], phase transfer [15], solid hydrogen storage [16], plasma catalysis [17], catalytic combustion [18], minerals [19], small molecules [20], transition metals [21], computational study/machine learning [22,23], enzyme [24], polymerization [25], water oxidation [26], photoredox catalysis [27,28], photocatalysis [29], artificial photosynthesis [30], fluid catalytic cracking [31], gasoline automobile catalysis [32,33], nanozymes [34], "the origin of life" [35], applied/industrial catalysis [1,36,37], etc.) and particular catalysts (e.g., Ziegler-Natta catalysts [38]), but also to the specific countries (e.g., Korea [39], Brazil [40][41][42], Portugal [43], Italy [44], and India…”