Synthesis of Functionalized Triphenylenes via a Traceless Directing Group Strategy

Abstract

A novel ligand-free Pd-catalyzed cascade reaction between o-chlorobenzoic acids and cyclic diaryliodonium salts is reported. This one-pot procedure involves a carboxylic acid directed o-arylation followed by intramolecular decarboxylative annulation affording various valuable triphenylenes, which can be further transformed into diversified building blocks for material chemistry. For the first time, it was shown that an aromatic halide can react with diaryliodonium salts under the direction of carboxylic acid functionality. It was also demonstrated that the carboxylic acid could be employed as both a traceless directing group and functional handle for the atom- and step-economical one-pot double cross-coupling annulation reaction with cyclic diaryliodonium salts as the π-extending agents.

Annulative π-Extension of Unactivated Benzene Derivatives through Nondirected C–H Arylation

“…Our study commenced with the nondirected approach using benzene ( 1a ), − which is underdeveloped as compared with the well-established directed syntheses. Cyclic diphenyliodonium salt ( 2a ) was employed as an aryl appending agent. ,− After extensive screening of palladium catalysts and reagents (see also the SI, section III), reaction conditions for the Pd-catalyzed 2-fold C–H activation relay were established to give 3aa in 65% yield (Table , entry 1) under acidic conditions. In the absence of Pd­(TFA) 2 , TFA, or AgSbF 6 , the triphenylene scaffold was not produced (entries 2–4), indicating that this nondirected APEX involves an electrophilic palladation event. , Replacement of Pd­(TFA) 2 by Pd­(OAc) 2 resulted in a lower yield (entry 5).…”

Peptide Functionalization Through the Generation of Selenocysteine Electrophile

“…Besides, selenium‐modified benzo[ g ]chrysene ( 13f ) formation was achieved in mild, simple and selective reaction. Synthesis of polycyclic aromatic hydrocarbons is a pertinent topic due to its physical and chemical properties …”

Copper‐Catalyzed Diphenylation of P(O)‐OH Bonds with Cyclic Diaryliodonium Salts

“…have presented an efficient method for the formation of functionalized carbazoles via the copper‐catalyzed amine insertion into cyclic diphenyleneiodonium compounds . Later, Zhang and co‐workers have further disclosed a divergent transition metal‐catalyzed coupling of benzoic acid and their derivatives with cyclic diaryliodonium salts for the selective synthesis of 2′‐iodo‐[1,1′‐biphenyl]‐2‐yl benzoate, 2′‐alkynyl‐[1,1′‐biphenyl]‐2‐yl 2‐aminobenzoate, and triphenylene derivatives Although the arylation of P(O)−OH bonds with linear aryliodonium compounds via the assistance of a base was reported, a stoichiometric amount of iodobenzene is released after the reaction, and the recovery of iodobenzene increases the burden in purification . Herein, we demonstrate an efficient direct cross‐coupling reaction of P(O)−OH bonds with cyclic diphenyliodonium species to construct functionalized 2′‐iodo‐[1,1′‐biaryl]‐2‐yl phosphonates and phosphates, catalyzed by cheap copper species under mild conditions (Scheme ).…”