Palladium-catalyzed tandem bis-allylation of isocyanates

[GRPAHICS] A tandem bis-allylation of p-toluenesulfonyl isocyanate can be achieved by palladium-catalyzed three-component coupling reaction with allylstannanes a nd allyl chlorides, A high level of regioselectivity can be obtained by the appropriate choice of the allylic substituents. The reaction mechanism and the regiochemistry of the reaction can be explained by formation of an amp hoteric bis-allylpalladium intermediate, This bis-allylpalladium intermedia te undergoes an initial electrophilic attack on one of the allyl moieties f ollowed by a nucleophilic attack on the other.