An Efficient Cobalt(I) Catalyst System for the Selective 1,4-Hydrovinylation of 1,3-Dienes This work was supported by the Deutche Forschungsgemeinschaft (DFG).

Abstract

Not a Diels-Alder reaction but a 1,4-hydrovinylation takes place on treatment of 1,3-dienes with functionalized alkenes in the presence of the catalyst system [CoBr₂ (dppe)]/ZnI₂ /Bu₄ NBH₄ (dppe = 1,2-bis(diphenylphosphanyl)ethane). With this reaction the 1,4-dienes with different substituents R¹ -R⁴ can be obtained in high selectivity and good to excellent yields.