ChemInform Abstract: Copper‐Catalyzed Aromatic C—H Bond Halogenation Using Lithium Halides as Halogenating Reagents.

Abstract

The copper‐mediated C‐H chlorination and bromination of 2‐arylpyridines, substituted with both electron‐donating and electron‐withdrawing groups affords the halogenated products in low to moderate yields and poor selectivity.

The Influence of Copper on Halogenation/Dehalogenation Reactions of Aromatic Compounds and Its Role in the Destruction of Polyhalogenated Aromatic Contaminants

“…Highly regioselective ortho-halogenations of substituted 2-phenylpyridines catalyzed by Cu(II) salts were described by several research groups [41][42][43][44]. Pyridine works as a monodentate directing group in this case (Scheme 6).…”

“…Scheme 7. Proposed mechanism of ortho-halogenation of 2-phenylpyridine catalyzed by CuX2 (X = bromide, chloride or anion of carboxylic acid) [41][42][43][44].…”

“…Different sources of nucleophiles were used, concretely I2 (for ortho-iodination), Scheme 7. Proposed mechanism of ortho-halogenation of 2-phenylpyridine catalyzed by CuX 2 (X = bromide, chloride or anion of carboxylic acid) [41][42][43][44].…”

Chlorination of (Phebox)Ir(mesityl)(OAc) by Thionyl Chloride

“…Carbon-chlorine bonds are widespread in pharmaceutically important organic molecules [1]. Organochlorides are also common synthetic precursors for cross-coupling [2], such as the Suzuki-Miyaura reaction [3]. In recent years C-H bond functionalization, involving initial C-H bond activation followed by functionalization of the resulting metal-carbon bond [4,5,6,7], has shown great promise in organic synthesis for constructing C-Cl bonds directly from C-H bonds [1,2,8,9,10,11,12].…”

“…Besides Pd, Rh and Cu catalysts for carrying out arene C-H chlorination have been reported [2,13,14]. The Shilov Pt system is well-known for effecting the chlorination of methane, but studies on other substrates are rare [4,7].…”