Ruthenium(II)‐Catalyzed Chelation‐Assisted Arylation of CH Bonds with Diaryliodonium Salts

Abstract

Chelation‐assisted arylation of the ortho CH bonds in 2‐arylpyridine derivatives was achieved by using [Ru(OAc)2(p‐cymene)] as the catalyst and diaryliodonium salts as the arylation reagent. The reaction can tolerate a broad range of functional groups and, in contrast to other Ru‐catalyzed CH arylation reactions with diaryliodonium salts, appears to proceed by a mechanism similar to Pd‐catalyzed CH arylation.

Advances in Synthetic Applications of Hypervalent Iodine Compounds

“…Transition metal-catalyzed arylations of organic substrates with diaryliodonium salts have been summarized in several reviews and books. ,,,, Recently, numerous regio- and stereoselective arylations in inter- or intramolecular mode using transition metal catalysts, such as copper, − palladium, − silver, nickel, iron, iridium, and ruthenium, have been reported. Particularly important is the copper-catalyzed, directed meta -selective C–H arylation of aromatic compounds with amido substituents reported by Gaunt .…”

Nickel Catalysts/N,N′-Bidentate Directing Groups: An Excellent Partnership in Directed C–H Activation Reactions

“…Furthermore, aliphatic amides bearing a tertiary α-carbon gave the monoarylated product 209 in moderate yield. After developing the first ruthenium(II)-catalyzed directed ortho CH arylation using diaryliodonium salts 30 (easily prepared, air-stable, nontoxic compounds) 31 and inspired by the report of Shi and co-workers on the Pd-catalyzed arylation of C(sp 3 )H bonds in aliphatic amides containing an 8-aminoquinoline moiety as the directing group using diaryliodonium salts as coupling electrophiles, 32 our group reported on the first example of a nickel(II)-catalyzed β-C(sp 3 )H arylation with hypervalent iodine(III) reagents, and the 8-aminoquinoline as a suitable directing group (Scheme 12). 33 In this system, in contrast to our previous work with aryl iodides, 24 the arylated products were obtained in good yields even in the absence of a carboxylic acid.…”

Diaryliodonium Salts in Transition‐Metal‐Catalyzed Chelation‐Induced C(sp2/sp3)−H Arylations

“…In 2014, a selective Ru(II)‐catalyzed ortho ‐arylation of 2‐phenylpyridine using diaryliodonium salts was established by the research group of Chatani where K 2 CO 3 in toluene at 80 °C was employed to obtain ortho ‐arylation product of 2‐phenylpyridine (Scheme 20). [53] In addition, some other bases like Na 2 CO 3 , NaOAc, and KOAc were also fruitful in this transformation. AcOH was used as an alternative solvent in some cases to enhance the yield.…”