Dynamic behaviour of monohaptoallylpalladium species: internal coordination as a driving force in allylic alkylation chemistry.

Contemporary catalytic procedures involving alkylpalladium(ii) have enriched the arsenal of synthetic organic chemistry. Those transformations usually rely on internal coordination through "directing groups", carefully designed to maximize catalytic efficiency and regioselectivity. Herein, we report structural and reactivity studies of a series of internally coordinated monohaptoallylpalladium complexes. These species enable the direct spectroscopic observation and theoretical study of π-σ-π interconversion processes. They further display unusual dynamic behavior which should be of direct relevance to chemistries beyond catalytic allylic alkylation.