Observation of the first Heck-type cross-coupling reaction of allenes with aryl halides. Synthesis of polysubstituted 1,2-allenyl sulfones.

[reaction: see text] The Heck-type allenylation of aryl halides with allenes has been observed for the first time: The regioselectivity of intermolecular carbopalladation of 1,2-allenyl sulfones affording vinylic Pd intermediates is completely opposite to what was reported in the literature.