Diaryliodonium(iii) salts in one-pot double functionalization of C–I^IIIandorthoC–H bonds

Abstract

Since the 1950s, diaryliodonium(III) salts have been demonstrated to participate in various arylation reactions, forming aryl–heteroatom and aryl–carbon bonds. Incorporating the arylation step into sequential transformations would provide access to...

Palladium-Catalyzed Regioselective C-Arylation and C,N-Diarylation of N-Aryl-2,3-dihydrophthalazine-1,4-diones Using Diaryliodonium Salts

“…While the Narylated product (3՛ea) was obtained by the reaction of diphenyliodonium triflate (2a) with 1e using catalytic amount of Pd(OAc)2 in absence of XPhos and O2 atmosphere. Also, 3՛ea did not transform into the corresponding C,N-diarylated product (4ea) at all under Pd-catalyzed conditions in presence of XPhos, even heating the reaction mixture up to 12 h (Scheme 5v Based on our investigations and literature reports, [40][41] the Csp 2 -H arylation of N-aryl 2,3-dihydrophthalazine-1,4-diones (1) with diaryliodonium salts (2) can be believed to proceed via Pd II / IV catalytic cycle with the aid of KOAc for which the presence of oxygen is most crucial. Initially, coordination of 1a to Pd II -species followed by ortho Csp 2 -H activation forms a five-membered cyclopalladation species B via A (Scheme 6).…”

Transition-Metal-Free N-Arylation of N-Methoxysulfonamides and N,O-Protected Hydroxylamines with Trimethoxyphenyliodonium (III) Acetates

“…26 27 Treating 3aa with trifluoromethanesulfonic acid at –40 °C caused the migration of the tosyl group 28 to afford diaryl sulfone 3aa′ in 95% yield (Scheme 4 A), exemplifying double functionalization of C-I(III)/ ortho -C–H bonds of diaryliodonium salts. 9h N -­Benzyloxy- N -aryl-4-nitrobenzenesulfonamide 3mh underwent the reduction of nitro group and the deprotection of benzyloxy group in the presence of a catalytic amount of palladium charcoal in a hydrogen atmosphere to generate 4-amino- N -hydroxy- N -arylbenzenesulfonamide 4sh in 98% yield (Scheme 4 B). This structure represents the core structure of the sulfa drugs.…”

Utilization of Aryl(TMP)iodonium Salts for Copper-Catalyzed N-Arylation of Isatoic Anhydrides: An Avenue to Fenamic Acid Derivatives and N,N′-Diarylindazol-3-ones

“…Formulation of a practical strategy for arylation of heterocyclic molecules or heteroatom-based nucleophiles is of paramount importance and a powerful tool to architect the key building blocks in organic synthesis and medicinal chemistry . In the realm of arylation chemistry, the hypervalent iodine arylating compound i.e., diaryl-λ 3 -iodanes, (well known as diaryliodonium salts) have witnessed a dramatic upsurge as an efficient and versatile aryl-transferring reagent, either in metal-free or transition-metal-catalyzed methods . Though the inherent electrophilicity of this aryl donor is immensely applauded in metal-free arylation protocols, the arylation methodologies of diaryliodonium salts under copper catalysis are also quite familiar and illustrate remarkable examples of arylation reactions .…”