ORGN 297 |
| Since the pioneering work of Dolling et al. in 1984, asymmetric synthesis by chiral phase transfer catalysis has provided an attractive method of preparing various optically active compounds. However, most of the elaborated chiral phase transfer catalysts reported so far have been restricted to cinchona alkaloid derivatives, which unfortunately constitutes a major difficulty in rationally designing and fine-tuning of catalysts to attain sufficient reactivity and selectivity for various asymmetric transformations. Accordingly, sructurally rigid, chiral spiro-type ammonium salts derived from chiral binaphthol have been prepared and successfully applied to the catalytic enantioselective alkylation of tert-butyl glycinate-benzophenone Schiff base under mild phase transfer conditions. Quite recently, we successfully designed binaphthyl-modified, chiral quaternary ammonium salts as new, yet very active chiral phase transfer catalysts for practical asymmetric synthesis of alpha-alkylamino acids. These types of chiral catalysts can be also effected for asymmetric aldol and Strecker reactions. |
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Organocatalysis
1:00 PM-5:05 PM, Monday, 11 September 2006 Moscone Center -- Room 135, Oral
Division of Organic Chemistry |