Highly regio- and stereoselective synthesis of 2(E),4-Alkadienoates via the Pd(0)-catalyzed reaction of aryl halides with 3,4-alkadienoates.

[reaction: see text] 2(E),4-Alkadienoates were prepared highly stereoselectively via the Pd(0)/Ag(2)CO(3)-cocatalyzed reaction of 3,4-alkadienoates and aryl halides. The reaction is believed to proceed via the oxidative addition-carbopalladation-beta-H elimination process. Compared to the other reported methods for the synthesis of 2,4-alkadienoates, in which usually only disubstituted C=C bonds were formed, the current reaction forms the trisubstituted or even tetrasubstituted C=C bond highly stereoselectively.