Palladium nanoparticles stabilised by tris(3-sulfophenyl)phosphine trisodium salt in neat glycerol have been synthesised and fully characterised, starting from both Pd(II) and Pd(0) species. The versatility of this innovative catalytic colloidal solution has been proved by its efficient application in C À X bond formation processes (X = C, N, P, S) and C À C multiple bond hydrogenation reactions. The catalytic glycerol phase could be recycled more than ten times, preserving its activity and selectivity. The scope of each of these processes has demonstrated the power of the as-prepared catalyst, isolating the corresponding expected products in yields higher than 90%. The dual catalytic behaviour of this glycerol phase, associated to the metallic nanocatalysts used in wet medium (molecular-and surface-like behaviour), has allowed attractive applications in onepot multi-step transformations catalysed by palladium, such as C À C coupling followed by hydrogenation, without isolation of intermediates using only one catalytic precursor.

A new series of 2,4,6‐triaryl‐λ5‐phosphinines have been synthesized that contain different substituents both on the carbon backbone and the phosphorus atom of the six‐membered heterocycle. Their optical and redox properties were studied in detail, supported by in‐depth theoretical calculations. The modularity of the synthetic strategy allowed the establishment of structure–property relationships for this class of compounds and an OLED based on a blue phosphinine emitter could be developed for the first time.

Well‐defined and small copper(I) oxide nanoparticles stabilised by poly(vinylpyrrolidone) in neat glycerol have been synthesised under a dihydrogen atmosphere. The as‐prepared material has been successfully applied in Cheteroatom couplings and azide–alkyne cycloadditions to give the desired products selectively with isolated yields higher than 90 %. Different amines have been used in the CN couplings, which include aqueous ammonia, that led to the synthesis of anilines. Mono‐1,4‐disubstituted triazoles and also bis‐ and tris(triazoles) have been obtained by the regioselective Cu‐catalysed Huisgen reaction, which comprises the synthesis of dissymmetrical substituted bis(triazoles). The catalytic glycerol phase could be recycled at least ten times and keeps its activity and selectivity. Moreover this versatile catalyst allowed tandem cycloaddition/CN coupling processes to give the corresponding polyfunctional products in a high global yield without the isolation of intermediates.

This Minireview considers the foremost reported works involving glycerol as a solvent in the synthesis of organometallic complexes and metallic nanoparticles. This analysis highlights their catalytic applications. A special emphasis is devoted to the ability of glycerol to immobilize nanometric species, which, in turn, enables an efficient recycling of the catalytic phase to give metal-free organic products.

Palladium/TPPTS nanoparticles in glycerol represent a versatile catalyst leading to a large variety of heterocycles through domino/sequential one-pot approaches.

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An original and recyclable chiral bidentate aniline-sulfoxide-based directing group has been developed. This auxiliary allows challenging stereoselective Pd-catalyzed direct functionalization of small cycloalkanes through C-aryl and C-alkyl bond formation. Although moderate diastereoselectivities are observed, both optically pure enantiomers of the highly functionalized products can be obtained separately by simple silica gel chromatography and cleavage of the chiral auxiliary. This strategy was further applied to the preparation of enantiomerically pure 1,2,3-trisubstituted cyclopropane carboxylic acid derivatives, with three stereogenic centers and bearing both alkyl and aromatic substituents. These molecular scaffolds are not yet reported in the literature. The synthetic utility of this approach is validated by the chiral auxiliary being readily cleaved and recovered posteriori to the C-H activation step, without deterioration of its optical purity. Finally, an unprecedented palladacycle intermediate generated through C-H activation of the cyclopropane moiety has been isolated and fully characterized. Initial DFT calculations shed additional light on the reactivity of this original intermediate.

Catalytic systems combining ortho-(dimesitylboryl)phenylphosphines and palladium precursors have been evaluated in the Suzuki-Miyaura couplings of chloro-N-heterocycles, in particular 2-chloroA C H T U N G T R E N N U N G pyridines, with arylboronic acids. The Lewis basic character of the substrates does not interfere with the Lewis acidic site of the ligands, even for a substrate featuring free NH 2 groups. The influence of several reaction parameters has been studied and the ortho-dimesitylboryl moiety was actually found to substantially enhance the catalytic performance. The role of this group has been examined using preformed phosphine-borane/Pd complexes and the formation of an original phosphine/h 4 -boratabutadiene complex has been identified as a possible deactivation pathway. Regioselective coupling of 2,6-dichloro-3-nitropyridine with phosphine-borane/Pd catalysts has also been explored, and sequential double cross-couplings were found to give a direct and efficient access to unsymmetrical 2,6-diarylpyridines.