Dialumene-Mediated Production of Phosphines through P4 Reduction.

The formation of phosphorus-rich alanes featuring butterfly-like geometries is achieved. The two-electron reduction products feature a unique P4 2- structure and can act as a source of P3-. The treatment of these phosphorus containing products with electrophiles under mild conditions results in the formation of different phosphines. This approach eliminates the need for high temperatures and/or high pressures, which are commonly required in industrial processes for the preparation of useful phosphines.The activation and further functionalization of white phosphorus (P4) by main group complexes has become an increasingly studied topic in recent times. Herein, we report the controlled formation of phosphorus-rich alanes featuring butterfly-like geometries from the selective reaction of P4 with dialumenes, ([L(IiPr)Al]2) (1: L=Tripp=2,4,6-iPr3C6H2; 2: L=tBu2MeSi; IiPr=[MeCN(iPr)]2C)). The two-electron-reduction product of P4 features a P4 2- structure and is shown to be able to act as a source of P3-. Treatments of different electrophiles (e.g., chlorotrimethylsilane (Me3SiCl), iodotrimethylsilane (Me3SiI), HCl, or acetyl chloride (CH3COCl)) with these alanes under mild conditions gave the corresponding phosphines (e.g., P(SiMe3)3, PH3, or P(COCH3)3).

Tetryliumylidene ions in synthesis and catalysis.

Tetryliumylidene ions ([R-E:]+), recognised for their intriguing electronic properties, have attracted considerable interest. These positively charged species, with two vacant p-orbitals and a lone pair at the E(ii) centre (E = Si, Ge, Sn, Pb), can be viewed as the combination of tetrylenes (R2E:) and tetrylium ions ([R3E]+), which makes them potent Lewis ambiphiles. Such electronic features highlight the potential of tetryliumylidenes for single-site small molecule activation and transition metal-free catalysis. The effective utilisation of the electrophilicity and nucleophilicity of tetryliumylidenes is expected to stem from appropriate ligand choice. For most of the isolated tetryliumylidenes, electron donor- and/or kinetic stabilisation is necessary. This minireview highlights the developments in tetryliumylidene syntheses and the progress of research towards their reactivity and applications in catalytic reactions.