Synthesis and reactivity of azapalladacyclobutanes

N-Sulfonyl aziridines undergo oxidative addition to palladium(0) complexes generated in situ from mixtures of Pd-2(dba)(3) and 1,10-phenanthroline. The resulting azapalladacyclobutane complexes undergo intramolecular carbopalladation in the presence of copper(I) iodide to afford azapalladabicyclo-[3.2.1] octanes. A deuterium-labeling experiment indicates that the oxidative addition proceeds via S(N)2-type attack of palladium(0) on the less-hindered carbon of the aziridine ring and that alkene insertion occurs in a syn fashion. The azapalladabicyclo[3.2.1] octane complexes undergo oxidative palladium-carbon bond functionalization in the presence of copper(II) bromide.