Synthesis, Electronic Properties and OLED Devices of Chromophores Based on λ5 -Phosphinines.

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.

Enantiopure Sulfinyl Aniline as a Removable and Recyclable Chiral Auxiliary for Asymmetric C(sp3 )-H Bond Activation.

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.

Glycerol as suitable solvent for the synthesis of metallic species and catalysis.

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.