Palladium-catalyzed reductive coupling of acid chlorides with beta-stannyl enones: synthesis of 1,4-diketones and mechanistic aspects

Palladium catalyzes coupling reactions between acid chlorides and E-(1,2)-bis(tri-n-butylstannyl)ethene or beta-stannyl enones to produce butane-1,4-diones. The reaction involves reduction of an enedicarbonyl intermediate. Coupling reactions at low temperatures yield alpha, beta-unsaturated 1,4-diketones, and involve palladium hydride-promoted reduction. This method facilitates synthesis of two 1,4-diketone ipomeanines.