Palladium-catalyzed Reactions of 1,3-Dienes with Active Methylene Compounds. IV. Palladium-diphosphine Complex Catalysts

Abstract Active methylene compounds, such as acetylacetone and ethyl acetoacetate, reacted with 1,3-butadiene in the presence of palladium-diphosphine complex catalysts to yield two 1 : 1 adducts, 1 and 2. Primary and secondary amines also afforded two 1 : 1 adducts, 10 and 11. Isoprene, 1,3-pentadiene, and 2,4-hexadiene also reacted with the active methylene compounds and the amines in a manner similar to that of 1,3-butadiene. The most effective and easily available catalyst is the combination of PdBr2(Ph2PCH2CH2PPh2)2 and sodium phenoxide.