Copper-Catalyzed Selective Aryl-Allyl Coupling

Significance

The authors disclose a copper-­catalyzed addition of boronic esters to (Z)-allyl­phosphates. Transformations similar to this are common under palladium catalysis, but selective copper-mediated examples are rare. The yields of this reaction vary from moderate to good, but the E/Z selectivities and regiocontrol are excellent. When using non-racemic starting materials, the chirality is effectively transferred to the newly formed stereocenter with almost no degradation of ee.