The η 3 -Furfuryl Ligand: Plausible Catalytic Intermediates and Heterocyclic η 3 -Benzyl Analogues with Superior Binding Ability

Five-membered heterocyclic analogues of the well-known eta(3)-allyl and eta(3)-benzyl ligands, e.g., eta(3)-thienyl and eta(3)-furfuryl, have been proposed as catalytic intermediates, yet are poorly understood and have never been structurally confirmed. Herein we characterize an eta(3)-furfuryl complex by multinuclear R spectroscopy and crystallography and offer a computational survey of allyl and allyl-like ligands. Crystallographically and computationally, we show that the eta(3)-furfuryl ligand may bind more strongly than corresponding eta(3)-benzyl ligands and is plausible as a catalytic intermediate.