Marc Lafrance, Markus Roggen, and Erick M. Carreira Angew. Chem. Int. Ed.
Carreira’s group report a method for the direct enantioselective amination of racemic secondary allylic alcohols. Metal-catalysed allylic substitution is usually carried out with ester, carbonate or phosphate leaving groups; very few examples using the hydroxyl leaving group are reported. The group employ sulfamic acid as a surrogate for ammonia, allowing access to primary amines without over-substitution.
The amine products were isolated after an in situ protection. They showed that isolation as the Bz-, Ts, Fmoc-protected and HCl salt derivatives is feasible and that a wide variety of substitution on the aromatic ring is tolerated. Alkyl substitution is also well tolerated, enantioselectivity only begins to break down with more flexible substituents.