Syntheses of novel α,β-unsaturated chromium fischer carbene complexes using β-bromostyrene

Syntheses of α,β-unsaturated neutral Chromium Fischer carbene complexes bearing alkoxy groups as donor substituents have been explored. Treating β-bromostyrene with a base and chromium hexacarbonyl followed by alkylation with an alkyl iodide produced the alkoxystyryl carbene complexe 1 in modest yield. The results however did not show significant variation in the yield of 1 with the size of the side chain R. Owing to their resemblance to α,β-unsaturated carbonyl compounds, these compounds can provide very useful protocols for the synthesis of organic compounds. 1a. R = isopropyl (42.0%) 1b. R = isobutyl (40.0%) 1c. R = sec-butyl (45.3%) 1d. R = benzyl (41.2%)