Catalytic asymmetric protonation of fluoro-enolic species: access to optically active 2-fluoro-1-tetralone

✍ Scribed by Markus A. Baur; Abdelkhalek Riahi; Françoise Hénin; Jacques Muzart

• Book ID: 104360045
• Publisher: Elsevier Science
• Year: 2003
• Tongue: English
• Weight: 318 KB
• Volume: 14
• Category: Article
• ISSN: 0957-4166
• DOI: 10.1016/s0957-4166(03)00585-8

✦ Synopsis

Three racemic a-fluorinated benzyl b-ketoesters have been synthesized by electrophilic fluorination with Selectfluor™. They were submitted to our well established palladium-mediated cascade reaction (deprotection, decarboxylation and protonation of the resulting enolic species) producing optically active a-fluoro ketones. With benzyl 2-fluoro-1-tetralone-2-carboxylate as substrate, (S)-(-)-2-fluoro-1-tetralone with up to 65% enantiomeric excess was obtained using quinine as the chiral base and Pd/C type 807104 from Merck as the heterogeneous catalyst.