Isolable Arylphosphinidene Chalcogenides and their Radical Anions

We report the synthesis, characterization, and reactivity of isolable arylphosphinidene chalcogenides (Ar─P═E; 2 (E = S), 3 (E = Se), 4 (E = Te)), prepared via chalcogen atom transfer from tris(dimethylamino)phosphine chalcogenides (Me 2 N) 3 P═E (E = S, Se, Te) to a phosphanorcaradiene. The compounds crystallize at ambient temperature and feature P═E double bonds, as confirmed by structural and computational studies. Compounds 2 – 4 undergo [4+2] cycloaddition with 2,3‐dimethyl‐1,3‐butadiene to furnish six‐membered heterocyclic products, demonstrating their π‐bond reactivity. Compound 3 reacts with mesityl azide to afford a P(V) compound. Additionally, 2 and 3 are capable of oxidative cleavage of O─H and N─H bonds in H 2 O and NH 3 , respectively. Furthermore, 2 – 4 can be one‐electron reduced to their corresponding radical anion salts, which are unprecedented radical anions of pnictinidene chalcogenides isolable in the condensed phase.