Cuprous ferricyanide

Oxidation of cuprous acetylides by air or potassium ferricyanide brings about the union of two acetylenic groupings as in the preparation of dimethyldiacetylene (42%).. The reaction has been applied to the synthesis of diynediols from acetylenic carbinols. ... 

As already oudined, inhibition is essentially complete when caused by reagents that react with sulfhydryl groups (for example, p-chloro-mercuribenzoate, p-mercuribenzoate, o-iodosobenzoate, L-ascorbic acid silver, cupric, and mercuric ions iodine, and ferricyanide) this inactivation can be reversed to some extent by hydrogen sulfide and by cysteine. Lineweaver—Burk graphs have shown that the action of L-ascorbic acid is noncompetitive, and L-ascorbic acid acting in the presence of cupric ions probably causes formation of an inactive cuprous-enzyme. The action of p-chloromercuribenzoate on barley beta-amylase has been shown to be a competitive inhibition. In contrast, the soya-bean p-chloromercuribenzoate inhibition is noncompetitive, and the extent of inhibition is inversely related to the concentration of acetate ion. The latter exhibits a protective effect, and there... 

OXIDATIVE COUPLING Cuprous chloride. Ferric chloride-Dimethylformamide. Manganese dioxide. Palladium(ll) chloride. Potassium ferricyanide. Silver carbonate-Celite. Thallium(Ill) trifluoroacetate. 

Radicals Bromine azide. -Butyllithium. Cuprous acetate. N,N-Dichlorourethane. 4,4 -Dinilrodiphenylnitroxide. Iodine, oxidation. Iodobenzenedichloride. Manganic tris(acetyl-acetonate) Potassium /-butoxide. Potassium ferricyanide. Potassium mtrosodisulfonate. 

Spot tests for hydrazine can be based on this reaction if carried out in the presence of anions which form cuprous salts that are insoluble in ammonia. Ferricyanide and ferrocyanide ions, whose cupric salts are easily soluble in ammonia, are suitable. 

---