The First Example of the Friedel-Crafts Cyclization Leading to (10-Hydroxy-9,10-dihydroanthr-9-yl)phosphonium Salts without the Expected Bradsher Dehydration.

The reaction of (acetalaryl)arylmethanols with various phosphines PRRR (R = R = R = Ph; R = R = Ph, R = Me and R = R = Me, R = Ph) under acidic conditions (e.g., HCl, HBF, TsOH) unexpectedly led to the formation of (10-hydroxy-9,10-dihydroanthr-9-yl)phosphonium salts instead of the corresponding anthryl phosphonium salts.

Comprehensive Review on Synthesis, Properties, and Applications of Phosphorus (P, P, P) Substituted Acenes with More Than Two Fused Benzene Rings.

This comprehensive review, covering the years 1968-2022, is not only a retrospective investigation of a certain group of linearly fused aromatics, called acenes, but also a presentation of the current state of the knowledge on the synthesis, reactions, and applications of these compounds. Their characteristic feature is substitution of the aromatic system by one, two, or three organophosphorus groups, which determine their properties and applications. The (P, P, P) phosphorus atom in organophosphorus groups is linked to the acene directly by a P-C bond or indirectly through an oxygen atom by a P-O-C bond.