Unlocking the C-centered ring-opening of phosphiranium ions for a straightforward entry to functionalized phosphines

Phosphorus chemistry occupies a pivotal position in contemporary organic chemistry but significant synthetic challenges still endure. In this report, a class of electrophilic phosphiranium salts, bearing fluorinated benzyl quaternizing groups, is introduced for the direct synthesis of diversely β-functionalized phosphines. We show that, in comparison with regular quaternary phosphiranium salts, these species display the sought balance of excellent stability and high electrophilic reactivity that allow the unlocking of the C-centered ring-opening reactions with different classes of weak nitrogen-, sulfur- and oxygen protic nucleophiles. In the arena of strained heterocyclic chemistry, phosphacycles as appealing electrophilic P-containing building blocks are underestimated. Here, the authors report a class of electrophilic phosphiranium salts bearing fluorinated benzyl quaternizing groups for the direct synthesis of diverselyβ-functionalized phosphines.