Copper-catalyzed cyanation of arenes using benzyl nitrile as a cyanide anion surrogate
作者:Jisong Jin、Qiaodong Wen、Ping Lu、Yanguang Wang
DOI:10.1039/c2cc35046g
日期:——
The copper-catalyzedcyanation of arenes using benzyl nitrile as a cyanide anion surrogate furnishes aromatic nitriles in moderate to good yields. The cascade process involves a copper-catalyzed aerobic C-Hoxidation, a retro-cyanohydrination, and a copper-catalyzed aerobic oxidativeC-H functionalization.
Cut and paste! A Cu‐catalyzed aromaticCHcyanation with acetonitrile as the nitrile source by CCNcleavage has been developed (see scheme; TMEDA=N,N,N′,N′‐tetramethylethylenediamine). The reaction is catalytic in copper, and it is found that using (Me3Si)2 as an additive plays a critical role in promoting CCNcleavage and enhancing the reaction rate.
A palladium(II)/magnesium–lanthanummixedoxide (Pd(II)/Mg–La) catalyst is a reusable catalyst for cyanation of aromatic C–H bonds by using the combination of NH4HCO3 and DMSO as the ‘‘CN’’ source. Moderate to good yields of aromatic nitriles were obtained. An excellent regioselectivity was achieved using the present protocol. A tandem process involving Suzuki coupling followed by a cyanation reaction
Cobalt-Catalyzed CH Cyanation of Arenes and Heteroarenes
作者:Jie Li、Lutz Ackermann
DOI:10.1002/anie.201409247
日期:2015.3.16
Carboxylate assistance proved to be the key for the success of efficient cobalt(III)‐catalyzedCH cyanations. Thus, an in situ generated cationic cobalt complex was identified as a versatile catalyst for the site‐selective synthesis of various aromatic and heteroaromatic nitriles with ample substrate scope.
A chelation-assistedpalladium-catalyzed ortho-cyanation of the sp2 C−H bond by CuCN provided aromatic nitriles in moderate to good yields. Notably, the reaction could be conducted on a 10 mmol scale. The key intermediate of the natural product of Menispermum dauricum DC was concisely synthesized by the procedure. This new approach represents an exceedingly practical method for the synthesis of aromatic