One-Pot Preparation of Arylalkynes by a Tandem Catalytic Iodination of Arenes and Palladium-Catalyzed Coupling of Iodoarenes with Terminal Alkynes

Abstract

Iodination of activated arenes by air-oxidation is carried out in the presence of catalytic bismuth salts at room temperature. Subsequently, the formed iodoarenes react with terminal alkynes to give arylalkynes under a selected palladium-catalyzed coupling condition in the same pot.

Nitrogen Dioxide‐Catalyzed Electrophilic Iodination of Arenes

“…The same site-selectivity was also observed in the bismuth-catalytic iodination with molecular iodine. [20] We tried the iodination of several aromatic heterocycles including 1-methylimidazole, benzofuran, benzothiazole, indole and 2-phenylpyridine, but only a trace or small amount of iodination products was observed (Supporting Information, Table S4, entries [31][32][33][34].…”

“…[19] Subsequently, the BiA C H T U N G T R E N N U N G (NO 3 ) 3 -BiCl 3 system was found to be an effective catalyst for the aerobic iodination under an air atmosphere. [20] In 2007, Das and co-workers reported the ceric ammonium nitrate-catalyzed aerobic iodination of arenes, [21] but such a reaction required the use of 1 equivalent of I 2 , thus a half of iodine source was wasted. Other examples relative to the aerobic iodination of arenes are the reactions using I 2 /NaNO 2 /air/silica-supported H 2 SO 4 [22] or KI/air/NaNO 2 /H 2 SO 4 .…”

Oxidative Halogenation with “Green” Oxidants: Oxygen and Hydrogen Peroxide

“…Under these conditions, the reaction of anisole (1 d) in CH 3 CN gave 149 in 90 % yield, while m-xylene was iodinated in 62 % yield (Scheme 63). [185] The iodination of 1 d in the absence of solvent afforded 149 in 87 % yield. Although various catalysts were investigated, only nitrate salts were active, while BiCl 3 or CuCl 2 , for example, gave only a trace amount of the product.…”

Recent Advances in Bismuth-Catalyzed Organic Synthesis

“…For example, the combined Bi(NO 3 ) 3 ·5H 2 O and BiCl 3 shows high catalytic activity for the iodination of electron-rich arenes with iodine under air atmosphere at room temperature to give aryl iodides in good to high yields (Scheme 76) [104]. Recent studies by Barrett and co-workers implicated Bi(OTf) 3 to be the efficient Lewis acid catalyst in the reaction of various nitriles with tertiary alcohols to afford amides in good to excellent yields (Scheme 77) [105].…”