Nucleophilic Displacement Catalyzed by Transition Metal. III. Kinetic Investigation of the Cyanation of Iodobenzene Catalyzed by Palladium(II)

Abstract

The nucleophilic displacement of iodobenzene with potassium cyanide was carried out in HMPA in the presence of palladium(II) acetate. The reaction obeys the following kinetics; d[C_6H_5CN]/dt=k[Pd(OAc)_2]_0(M_KCN)^2/3 A reaction scheme composed of two cycles has been proposed: in one cycle Pd0 activates iodobenzene and in the other cycle Pd2+ assists the dissolution of potassium cyanide.

The Liebeskind–Srogl Cross‐Coupling Reaction and its Synthetic Applications

“…Conventional cyanation of aryl halides often requires harsh conditions and toxic cyanide sources . The Liebeskind–Srogl‐type cross‐coupling reaction between thiocyanates 102 and organoboronic acids was first described by Zhang and Liebeskind in 2006 as a good alternative to traditional cyanation (Scheme ) .…”

Improving palladium-catalyzed cyanation of aryl halides: development of a state-of-the-art methodology using potassium hexacyanoferrate(II) as cyanating agent

“…Typical reaction conditions were: DMF as solvent, 140-150°C and 2-12 h reaction time. Early studies by Takagi et al [36] led to a first mechanistic proposal. One especially important point was the fact that an excess of cyanide ions inhibits the catalytic cycle.…”

Copper‐Catalyzed Acyloxycyanation of Alkynes with Acetonitrile: Regioselective Construction of Cyclic Acrylonitriles by 6‐endo or 5‐exo Cyclization

“…Acetonitrile is an attractive cyano source, featuring several advantages: 1) it is abundant, affordable, and commonly used as a solvent; 2) it is a safe and atom‐economic “CN” source; 3) it can avoid the generation of high concentration of “CN” during cyanation processes . As highlighted by Takagi, the high concentration of cyanide may reduce catalytic efficiency of transition metal‐catalysts due to catalyst poisoning. Herein, we describe the first Cu‐catalyzed regioselective acyloxycyanation of alkynes with acetonitrile as the cyanating reagent.…”