Unlocking the Synthetic Potential of HMF Derivatives in Catalytic Asymmetric Aza‐Piancatelli Rearrangement

The Piancatelli rearrangement of (2‐furyl)carbinols has now become an efficient synthetic method for the construction of cyclopentenones. However, the use of substrates bearing a C‐5 substitution on the furan moiety of (2‐furyl)carbinols remains largely underexplored. In this study, we employed 5‐hydroxymethylfurfural (HMF) derivatives as substrates, obtained in a single step from HMF, a key platform molecule and flagship compound for biomass valorization, to achieve the first catalytic asymmetric aza ‐Piancatelli rearrangement of C‐5‐substituted (2‐furyl)carbinols. The resulting aza ‐cyclopentenones, which feature two contiguous stereogenic centers including one quaternary center, were obtained in total regio‐ and diastereoselectivities and in enantioselective manner up to 92.4:7.6 er.