The Piancatelli Reaction

Abstract

The Piancatelli reaction allows the synthesis of 4‐substituted cyclopentenone derivatives from furylcarbinols and various nucleophiles such as water, alcohols, or amines. Easily accessible classes of products produced by this methodology include 4‐hydroxy‐, 4‐alkoxy‐ and 4‐aminocyclopent‐2‐enones. Cascade Piancatelli reactions involving intramolecular conjugate additions to the resulting enone moiety can lead to polycyclic products. Since the development of catalytic versions of the reaction using Lewis and Brønsted acids, the methodology has attracted considerable attention and has found several applications in the synthesis of complex molecules, including natural products. Enantioselective Piancatelli reactions are also possible by utilizing chiral Brønsted acids as catalysts. This chapter describes in detail the proposed mechanisms as well as the scope and limitations of the Piancatelli reaction.

Catalytic Asymmetric Radical-Mediated Three-Component Piancatelli-Type Rearrangement of Furylalkenes

“…The Piancatelli reaction, , a rearrangement of α-furylcarbinols, allows straightforward access to functionalized cyclopentenones, which are not only prevalent structural motifs in natural products and pharmaceutical drugs but also versatile precursors in organic synthesis . In the past decades, the original stoichiometric amount of acid-promoted Piancatelli reaction has been extended to a large family of Lewis or Brønsted acid-based catalytic transformations compatible with various internal and external O-, N-, and C-nucleophiles .…”

Asymmetric Ketoalkylation/Rearrangement of Alkyenlfurans via Synergistic Photoredox/Brønsted Acid Catalysis

“…Multifunctionalized cyclopentanones are not only privileged structural motifs in many prostaglandins, prostanoid derivatives, natural products, and other bioactive molecules but also versatile synthetic intermediates in complex chemical syntheses . Nazarov cyclization, Pauson–Khand reaction, Piancatelli rearrangement, , and Rautenstrauch rearrangement could provide efficient methods to access these functionalized cyclopentenone structures. Among them, aza-Piancatelli rearrangement has become a powerful platform for the synthesis of trans -substituted 4-amino-5-aryl/alkylcyclopentenones from readily available furfuryl alcohols and N-containing nucleophiles .…”

Access to densely functionalized spirocyclopentenonyl oxindole frameworks via aza- and carbo-Piancatelli rearrangement

“…The aza-Piancatelli rearrangement typically requires a furan-2-carbinol and aniline to give aminocyclopentenone derivatives (Scheme 1c). 8 It should be noted that aminocyclopentenones offer vast opportunities for synthetic elaboration due to the presence of multiple functional groups within the scaffold.…”