An enantioconvergent C(sp(3)) C(sp(3)) coupling between racemic allenylic electrophiles and allcylzinc reagents has been developed. An Ir/(phosphoramidite,olefin) catalyst provides access to highly enantioenriched allenylic substitution products (93-99% ee) with complete regiocontrol (>50:1 rr in all cases) over the corresponding 1,3-diene isomers which are obtained predominantly when other metal catalysts are emplyed. The synthetic utility of the products obtained was highlighted in a variety of stereoselective transition metal-catalyzed difunctionalization reactions. Furthermore, a combination of experimental and theoretical studies provide support for a putative reaction mechanism wherein enantiodetermining C C coupling occurs via nudeophilic attack on a highly planarized aryl butadienylium pi-system that is coordinated to the Ir center in an /72-fashion.