Asymmetric, catalytic reactions of oxocarbenium ions are reported. Simple, chiral urea and thiourea derivatives are shown to catalyze the enantioselective substitution of silyl ketene acetals onto 1-chloroisochromans. A mechanism involving anion binding by the chiral catalyst to generate a reactive oxocarbenium ion is invoked. Catalysts bearing tertiary benzylic amide groups afforded highest enantioselectivities, with the optimal structure being derived from enantioenriched 2-arylpyrrolidine derivatives.
|Original language||English (US)|
|Number of pages||2|
|Journal||Journal of the American Chemical Society|
|State||Published - Jun 11 2008|
All Science Journal Classification (ASJC) codes
- Colloid and Surface Chemistry