Palladium-catalysed inter- and intramolecular formation of C–O bonds from allenes

Abstract

The Pd-catalysed formation of a C–O bond from allenes mainly occurs via the inter- or intramolecular reaction with a hydroxyl group belonging to an alcohol, a phenol or an acid. A carbonyl or a carbonate entity can also be involved. In most cases, the formation of the C–O bond is one step of a domino reaction leading also to a C–C or C–N bond, or to another C–O bond. Thus, a wide range of products, in particular highly functionalized heterocycles, have been synthesised. Catalytic cycles have been proposed but the mechanisms often remain speculative.