Iridium-Catalyzed Enantioselective Allyl-Alkene Coupling

The direct Ir-catalyzed cross-coupling between branched, racemic allylic alcohols and simple olefins is described. This transformation is catalyzed by an Ir-(P,olefin) complex and proceeds with high site selectivity and excellent enantioselectivity. The method allows rapid access to various 1,5-dienes or trienes and was used in the catalytic asymmetric synthesis of the gamma-secretase modulator JNJ-40418677.