Electron‐rich tertiary phosphines are valuable species in chemical synthesis. However, their broad application as ligands in catalysis and reagents in stoichiometric reactions is often limited by their costly synthesis. Herein, we report the synthesis and properties of a series of phosphines with 1‐alkylpyridin‐4‐ylidenamino and 1‐alkylpyridin‐2‐ylidenamino substituents that are accessible in a very short and scalable route starting from commercially available aminopyridines and chlorophosphines. The determination of the Tolman electronic parameter (TEP) value reveals that the electron donor ability can be tuned by the substituent pattern at the aminopyridine backbone and it can exceed that of common alkylphosphines and N‐heterocyclic carbenes. The potential of the new phosphines as strong nucleophiles in phosphine‐mediated transformations is demonstrated by the formation of Lewis base adducts with CO2 and CS2. In addition, the coordination chemistry of the new phosphines towards CuI, AuI, and PdII metal centers has been explored, and a convenient procedure to introduce the most basic phosphine into metal complexes starting from air‐stable phosphonium salt is described.

The particularly basic phosphines 1a-c readily form isolable, zwitterionic Lewis base adducts with SO that were fully characterized including by X-ray diffraction studies. Computational and reactivity studies show that these adducts readily release SO at room temperature driven by the formation of the corresponding phosphine oxides.

We report the synthesis and properties of the much sought-after tris(1,1,3,3-tetramethylguanidinyl) phosphine P(tmg) 3 , a crystalline, superbasic phosphine accessible through a short and scalable procedure from the cheap and commercially available bulk chemicals 1,1,3,3-tetramethylguanidine, tris(dimethylamino)-phosphine and phosphorus trichloride. The new phosphine exhibits exceptional electron donor properties and readily forms transition metal complexes with gold(I), palladium(II) and rhodium(I) precursors. The formation of zwitterionic Lewis base adducts with carbon dioxide and sulfur dioxide was explored. In addition, the complete series of phosphine chalcogenides was prepared from the reaction of P(tmg) 3 with N 2 O and the elemental chalcogens.

The chemical activation of SF6 has garnered considerable attention because of its possible utilization as cheap and safe reagent in chemical synthesis. Such a process becomes particularly attractive when combined...