Palladium-catalyzed cyanide metathesis: utilization of benzyl cyanide as an operator-benign reagent for aryl halide cyanations

Cu‐Catalyzed Cyanation of Arylboronic Acids with Acetonitrile: A Dual Role of TEMPO

“…Twop athways for the formation of TEMPOÀCH 2 CN (6)a re possible. In path A, TEMPO directly abstracts ah ydrogena tom from acetonitrile to form the CCH 2 CN radical, which is trapped by as econd molecule of TEMPO to yield TEMPOÀCH 2 CN (6) and TEMPOH (12) [19, 20b] (detected by GC, see the Supporting Information,f or details). In path B, owing to the coordination ability of the nitrile group onto the Cu species, acetonitrile is selectively activated and deprotonated by base to generate the active Cu intermediate 10,…”

Copper‐Mediated Cyanation of Aryl Halides by Activation of Benzyl Cyanide as the Cyanide Source

“…It is noteworthy that 3k could be obtained in 86 % yield, which is the key intermediate for the manufacture of Sartan's medicines 21. In comparison with our previous finding, palladium‐induced migration of the cyano group was effectively avoided in this process 14a. Moreover, the reaction proceeded smoothly for fused aryl iodides and heterocyclic compounds 3l and 3m , and double cyanation occurred in case of 3m .…”

“…The dichloromethane was evaporated under reduced pressure and the residue was purified by flash column chromatography on silica gel (EtOAc/hexane, 1:8, v/v) to give 3a (61 mg, 92 % yield) as a white solid. M. p. 59–60 °C (Lit 14a. 60–61 °C).…”

Functionalization of the imidazo[1,2-a]pyridine ring in α-phosphonoacrylates and α-phosphonopropionates via microwave-assisted Mizoroki–Heck reaction

“…The second side product, compound 5, is probably the result of the cleavage of the C-CN bond in the solvent (propionitrile or acetonitrile), followed by a palladium-catalyzed cyanation of substrate 1. Recently, acetonitrile was reported as a nontoxic source of cyanide [19,20]. Having the optimized conditions in hand, the scope of this transformation was examined using selected olefins and the substrate containing imidazo[1,2-a]pyridine ring embedded either within 2-(diethoxyphosphoryl)acrylate (analogs 1) or 2-(diethoxyphosphoryl)propanoates (analogs 2).…”