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Metal complex catalysis, in which coordination compounds are designed as catalysts for chemical transformations employing noncovalent interactions, is emerging as a powerful catalytic method for organic synthesis. One of the main advantages of metal catalysis is that coordination compounds can promote various organic transformations not only by coordination bond but also through noncovalent interactions, such as hydrogen, halogen, chalcogen, pnictogen, tetrel and triel bonds, as well as metal-metal, cation-π, anion-π, lone pair-π, π-π stacking, agostic, pseudo-agostic, anagostic, dispersion-driven, lipophilic, etc., or their cooperation. In recent years, the concept of designing metal complex catalysts with noncovalent bond donor or acceptor sites has emerged as a promising strategy for developing selective catalytic transformations. In this review we discuss several recent relevant examples on the auxiliary/crucial role of noncovalent interactions in functionalization of alkanes, alkenes, alkynes, aromatics, heterocycles, aldehydes, ketones and alcohols catalyzed by metal complexes.

This review describes how non-covalent interactions, such as hydrogen (inter- and intramolecular, resonance- and charge-assisted hydrogen bonding), halogen, chalcogen and pnicogen bonds, π-interactions, as well as other types of weak forces can influence and control the reactions in the synthesis, e.g., of metal-containing supramolecular networks, providing a class of highly directional stabilizing contacts that can be exploited in the design of coordination compounds. The selected recent examples show that both inter- and intramolecular non-covalent interactions can influence the formation of coordination compounds. This overview of non-covalent interactions applied for synthesis and design of coordination compounds also contributes to an improved understanding of their behavior in crystal engineering, catalysis, etc. It provides a practical consultation for synthetic chemists that are interested in exploring and further developing non-covalent interactions assisted synthesis and design of coordination compounds.

Peroxides form an important class of chemicals in which two oxygen atoms are linked together by a single covalent bond (R−O−O−R, R=H, SO3K, alkyl, etc.), with a wide range of applications in medicine, industry, environmental protection, etc. The current version of the Cambridge Structural Database reveals more than 1400 structurally characterized metal-peroxy/peroxo complexes with diverse coordination modes having specific biological, catalytical and other functional properties. Both inorganic and organic peroxides are versatile oxidants and extensively used reagents for metal complex catalyzed functionalization of organic compounds. The utilization of peroxides in metal complex catalysis typically requires prior activation of O−O or O−R bonds at a metal centre leading to radical species with a reactivity and lifetime that are dependent on the substituents R and reaction medium (pH, solvent, etc.). In fact, the cooperation of a metal centre (coordination) with a peroxide can lead to a multifunctional catalytic system having a high performance towards selective functionalization of organic substrates. This review is intended to focus on the auxiliary/crucial role of peroxides in the transformations of various classes of organic compounds such as alkanes, alkenes, alkynes, aromatics, heterocycles, aldehydes, ketones and alcohols, catalyzed by metal complexes.

Nitroxyl radicals, illustrated by 2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPO), constitute a versatile class of stable free radicals that are extensively used in metal complex catalyzed synthetic transformations of a great interest. The Cambridge Structural Database reveals more than 260 hits, concerning crystal structures of metal complexes of N-oxyl ligands and most of them (ca. 240) relate to complexes comprising TEMPO and its derivatives. In order to prepare multifunctional catalysts, supramolecular architectures, drugs, magnetic materials, etc., the para-position of TEMPO has been functionalized with OH, COOH, CN, NH2 or N3, leading to an increase of the coordination sites beyond the N O· synthon. Herein, we highlight the coordination mode and reactivity of TEMPO ligands in the design of coordination compounds, which can be applied in catalysis. The review mainly focuses on the auxiliary/crucial role of TEMPO in functionalization of alkanes, alkenes, alkynes, aromatics, heterocycles, aldehydes, ketones and alcohols, catalyzed by metal complexes.

In spite of its impressive record in medicinal chemistry, the role of barbituric acid H 3 BA (pyrimidine-2,4,6(1 H ,3 H ,5 H )-trione) in coordination, organometallic and supramolecular chemistries has not yet been analyzed and reviewed. However, H 3 BA can be readily functionalized and provides rich opportunities to create coordination bonds and non-covalent interactions. Thus, derivatives of H 3 BA (barbituric acids, BAs) are widely used for the preparation of a wide range of complexes with various metals of almost all groups of the periodic table. The review systematizes information on the synthesis, tautomerism, acid–base properties of BAs and their use for the construction of organometallic and coordination compounds, as well as coordination polymers and supramolecular assemblies. The role of different metal ions and the structure of BAs in directing the preparative pathways and tuning particular structural properties of the resulting compounds are discussed. Some valuable applications of BAs, in particular in the construction of molecular receptors, magnetic and nonlinear optic materials, bioactive compounds, drug cocrystal design, catalysis and photochemistry are also envisaged.

The methods of synthesis of arylhydrazones of methylene active compounds (AHMACs) as well as the preparation and properties of their metal complexes are reviewed. Nuclearity, supramolecular arrangements and other features (e.g., solubility, redox potentials, catalytic and antibacterial activities) of the complexes can be controlled by the introduction of different substituents to the methylene active and/or the aromatic fragments of AHMAC and by variation of metal-ions used in the synthesis.