Memory and dynamics in Pd-catalyzed allylic alkylation with P,N-ligands

The memory effect, known to exert a strong influence on selectivity in some applications of the Pd-catalyzed allylic alkylation, has been investigated for a catalytic system based on a bidentate P,N-ligand. Although this system might be expected to show strong memory effects due to the difference in the trans influence of the two donor atoms (P > N), isotopic labeling revealed an almost complete absence of regio-retention. Modeling of dynamic processes in the intermediate (eta(3)-allyl)Pd complex allowed this observation to be rationalized in terms of anion-assisted apparent rotation. The study has allowed seemingly conflicting reports on the behavior of (eta(3)-allyl)Pd systems to be unified by a computational model. (C) 2010 Elsevier Ltd. All rights reserved.