Synfacts 2007(12): 1273-1273  
DOI: 10.1055/s-2007-991379
Metal-Catalyzed Asymmetric Synthesis and Stereoselective Reactions
© Georg Thieme Verlag Stuttgart · New York

Phosphine-Directed Diastereoselective Allylic Substitutions

Contributor(s): Mark Lautens, Frédéric Ménard
T. Spangenberg, A. Schoenfelder, B. Breit*, A. Mann*
CNRS, Illkirch, France and Albert-Ludwigs-Universität Freiburg, Germany
Further Information

Publication History

Publication Date:
22 November 2007 (online)

Significance

The authors report a solution to the challenge of creating a new stereogenic center next to a pre-existing one by a simple strategy. A ‘directing leaving group’ delivers the external nucleophile exclusively at the most hindered position, and the diastereoselectivity is controlled by the geometry of the alkene. Most of the current methods to prepare β-branched amino acids are based on intramolecular rearrangements. The application of the method was demonstrated in the synthesis of the natural amino acid 8.