The reaction of thermal decomposition of 4-nitrobenzenediazonium tosylate in tetrahydrofuran, dimethylsulfoxide and dimethylformamide medium with iron ace tylacetonates (III) has been studied. It was shown that catalyst addition increases considerably the reactivity of 4-nitrobenzenediazonium tosylate. The authors are first to develop the method of styrene arylation in tetrahydrofuran with 4-nitrobenzenediazonium tosylate at catalysis with iron acetylacetonates.