Enantioselective construction of quaternary tetrahydropyridines by palladium-catalyzed vinylborylation of alkenes.

Here, the highly enantioselective construction of 3,3-disubstituted tetrahydropyridines via Pd(0)-catalyzed asymmetric vinylborylation of (Z)-1-iodo-dienes and B2pin2 in the presence of a (S)-p-CF3-BnPHOX ligand is reported. This process is supposed to be initiated by oxidative addition of Pd(0) to vinyl iodide, followed by transmetallation with B2pin2, insertion of the pendant alkene and reductive elimination of alkyl-Pd(ii)-Bpin.