Potassium hexacyanoferrate(II)

Abstract

(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 K4[Fe(CN)6)] as cyanide source. (Image Presented) (B) Cyanation of Aroyl Chlorides: The cyanation of aroyl chlorides by using K4[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. (Image Presented) (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 K4[Fe(CN)6)].21 (Image Presented) (D) Synthesis of Arylvinyl Nitriles: The preparation of various arylvinyl nitriles has be achieved by cyanation of the corresponding arylvinyl bromides using K4[Fe(CN)6)] in ionic liquid under microwave irradiation catalyzed by palladium.24 (Image Presented) (E) The Stereoselective Synthesis of Fully Substituted α,β-Unsaturated Nitriles: A convenient and practical method for one-pot stereoselective synthesis of fully substituted a,b-unsaturated nitriles from aryl bromides, internal alkynes and K4[Fe(CN)6)] catalzyed by palladium in N,N-dimethylacetamide (DMAc) has been developed. 25 (Image Presented) (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 K4[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. (Image Presented) (G) One-Pot Synthesis of 5-Substituted 1H-Tetrazoles: Cai and co-workers reported a new and general method for the onepot synthesis of 5-substituted 1H-tetrazole through three-component reaction of aryl bromide, NaN3, and K4[Fe(CN)6)] in the presence of catalyst Pd(OAc)2, the additive ZnBr2 and 1,4-diazabicyclo- [2.2.2]octane (dabco).27 (Image Presented) (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 (Image Presented). © 2010 Georg Thieme Verlag Stuttgart, New York.