The enantioselective construction of derivatives of g-amino butyric acid and d-amino pentanoic acid from simple starting materials using asymmetric catalysis provides convenient access to a range of structurally diverse natural products, pharmaceutical compounds, and potential building blocks for g-peptides and foldamer chemistry.[1] Several natural products containing the aminoethylene and aminopropylene scaffolds attached to a quaternary stereocenter have been isolated. Developments in the field of enantioselective Michael additions of carbonyl compounds to nitroolefins and acrylonitriles have been significant, with highly enantioselective examples reported in both cases. [2,3] We recognized that structures containing aminoethylene or aminopropylene moieties could be accessed rapidly and stereoselectively if suitable two-carbon or three-carbon nitrogen-containing electrophiles could be utilized. To this end, we recently described both the base-catalyzed, [4a] and the phasetransfer catalyzed enantio-and diastereoselective [4b] ringopening reactions of nitrogen-protected aziridines as a method for the direct construction of g-amino butyric acid derivatives. During the course of that study, we found that sulfonyl protection of the nitrogen atom was necessary to achieve acceptable levels of reactivity. Although the sulfonyl group could be cleaved under mild conditions in some cases, we believed that a method which encompassed a wider range of nitrogen-protecting groups would be more desirable. Furthermore, access to the aminopropylene unit (CH 2 CH 2 CH 2 NHP) remained elusive. Anticipating that azetidines would lack the required reactivity to be used as threecarbon electrophiles, [5] we considered cyclic sulfamidates as potential two-or three-carbon electrophile candidates. [6,7] Seminal work by Lubell and Wei [8] and extensive studies by Gallagher and co-workers [9,10] have found that five-membered and six-membered cyclic sulfamidates are useful precursors for the synthesis of pyrrolidine and piperidinone alkaloids. In those studies, methylene carbon acids were typically used as the nucleophile, with chiral enantiopure electrophiles. To the best of our knowledge, there have been no reports of a catalytic enantioselective nucleophilic ring-opening of cyclic sulfamidates with carbon-centered nucleophiles, despite the synthetic advantages of such an approach. We reasoned that a base-catalyzed reaction would be challenging, owing to the low basicity of sulfamic acid salts that can be formed from the ring opening of cyclic sulfamidates. Accordingly, we believed that an enantioselective ring-opening of cyclic sulfamidates could be realized using asymmetric phase-transfer catalysis with a stoichiometric base. [11,12] Attracted by the simplicity of the approach, and the synthetic potential of the methodology, we began our investigations. Herein, we report our findings into the direct enantioselective catalytic alkylation reaction of methine pro-nucleophiles with N-protected five-membered and six-membered cyclic sulfami...

Erfolgreich selektiv: Die enantio‐ und diastereoselektive nucleophile Ringöffnung fünf‐ und sechsgliedriger cyclischer Sulfamidate unter asymmetrischer Phasentransferkatalyse wird beschrieben. Eine Vielzahl an Pränucleophilen konnte mit guten Ausbeuten und Enantioselektivitäten alkyliert werden.