Abstract
We herein describe a highly diastereoselective Cu(I)-catalyzed defluoroborylation of pentafluoroethyl alkenes using a diboron reagent (pin)B-B(dan). When 1,1- or 1,2-disubstituted pentafluoroethyl alkenes are employed as substrates, tetra- or trisubstituted fluoroalkenes can be obtained, respectively, in up to >99:1 diastereoselectivity. This protocol provides access to novel allyl-B(dan) compounds and allylic alcohols with alkene moieties containing F and CF(3) on the same carbon.