Table 2. Scope and conformational behavior of all-cis-4-fluoropiperidines.
Reactions were carried out on a 0.5–1.0 mmol scale. Yields were determined after column chromatography (TFA-analogues) or precipitation (HCl-analogues). Diastereomeric ratio (d.r.) values were determined by 19F NMR or GC analysis prior to purification. The conformational behavior was determined by NMR studies. For details concerning catalyst loading, see Supplementary Section 4. aSee general procedure B in Supplementary Section 4 for the deprotection of TFA-fluoropiperidines to generate the fluoropiperidine hydrochloride analogues.