Scheme 1.
A. The traditional approaches for accessing β-functionalized carbonyl compounds. B. Recently innovative approaches for direct β-functionalization of carbonyl compounds. C. Representative examples of naturally occurring and synthetic small molecules containing the 6-azabicyclo[3.2.1]octane ring system. D. Reported synthetic routes for 6-azabicyclo[3.2.1]octan-3-one. E. Novel direct β-C–H functionalization strategy in this study.
