Nucleophilic Attack at the Central Carbon Atom of (π‐Allyl)palladium Complexes: Formation of α‐Cyclopropyl Esters

Distinctly higher yields of functionalized cyclopropanes such as 1 can be achieved when 1,2-bis(dimethylamino)ethane, followed by CO, are added to the reaction of π-allylpalladium complexes with lithium enolates of esters. The usual, energetically favored allylic alkylation is efficiently suppressed in this way. The role of the amine ligands is crucial: addition of 1,2-bis(dimethylamino)methane produces no cyclopropanation product; with sparteine only low yields are obtained.