Potassium Hexacyanoferrate(II)

(A) Cyanation of Aryl Halides: An efficient Pd/C-PEG-H2O system for the cyanation of aryl halides has been developed by Wan and co-workers.(7) A wide range of aryl bromides, iodides, and some activated chlorides were cyanated smoothly by using K-4[Fe(CN)(6))] as cyanide source. [GRAPHICS] (B) Cyanation of Aroyl Chlorides: The cyanation of aroyl chlorides by using K-4[Fe(CN)(6))] instead of strongly toxic metal cyanides provides a convenient method to prepare aroyl cyanides.(19) The reactions could be efficiently catalyzed by the AgI-PEG 400-KI system under mild conditions. [GRAPHICS] (C) Cyanation of Aryl Perfluorooctylsulfonates: Zhu and co-workers have reported that aryl perfluorooctylsulfonates can be converted into benzonitriles in the presence of Pd(OAc)(2), CuI, and Ph3P or 1,1-bis(diphenylphosphino) ferrocene (dppf) applying K-4[Fe(CN)(6))].(21) [GRAPHICS] (D) Synthesis of Arylvinyl Nitriles: The preparation of various arylvinyl nitriles has be achieved by cyanation f the corresponding arylvinyl bromides using K-4[Fe(CN)(6))] in ionic liquid under microwave irradiation catalyzed by palladium.(24) [GRAPHICS] (E) The Stereoselective Synthesis of Fully Substituted alpha,beta-unsaturated Nitriles: A convenient and practical method for one-pot stereoselective synthesis of fully substituted alpha,beta-unsaturated nitriles from aryl bromides, internal alkynes and K-4[Fe(CN)(6))] catalzyed by palladium in N,N-dimethylacetamide (DMAc) has been developed.(25) [GRAPHICS] (F) Synthesis of Functionalized 3-Alkyl-3-cyanomethyl-2-oxindoleles: Zhu and colleagues reported an efficient synthetic method for various functionalized 3-alkyl-3-cyanomethyl-2-oxindoleles by a domino intramolecular Heck-cyanation sequence using K-4[Fe(CN)(6)] as a cyanide donor in the presence of palladium acetate and sodium carbonate. (26) The enantiomerically enriched 2-oxindoles were also obtained by this method using (S)-Difluorphos as a chiral supporting ligand. [GRAPHICS] (G) One-Pot Synthesis of 5-Substituted 1H-Tetrazoles: Cai and co-workers reported a new and general method for the one-pot synthesis of 5-substituted 1H-tetrazole through three-component reaction of aryl bromide, NaN3, and K-4[Fe(CN)(6))] in the presence of catalyst Pd(OAc)(2), the additive ZnBr2 and 1,4-diazabicyclo[2.2.2]octane(dabco).(27) [GRAPHICS] (H) Synthesis of Polysubstituted Aromatic Nitriles: Lautens and co-workers also showed that a tandem intermolecular ortho-arylation-cyanation reaction can be achieved by combining an aryl iodide with an alkyl halide or an aryl bromide followed by cyanation. In this way, polysubstituted aromatic nitriles can be prepared in one step.(28) [GRAPHICS]