Metal‐ and Solvent‐Free Phosphine Mediated Synthesis of Multisubstituted Furans via Intramolecular Annulation of 1, 4‐Enediones

Abstract

This paper describes the synthesis of multisubstituted furans through tricyclohexylphophine mediated intramolecular annulation of 1, 4‐enediones under solvent‐free greener reaction conditions. The reaction proceeds via nucleophilic attack of P(Cy)3 on the β‐carbon of 1, 4‐enediones to form oxaphosphetanes with new C–O bond formation which further eliminates O=P(Cy)3 to afford furans. The present methodology is compatible with a wide range of substrates and enabled the synthesis of a broad range of biologically significant furan derivatives in good to excellent yields (55–93%).

Photoredox-Mediated Aerobic Oxidative Cleavage of 1,3-Diketones to Access 1,2-Diketones and (Z)-1,4-Enediones

“…1,2-Diketones and 1,4-enediones are key structural motifs of natural products and pharmaceuticals. , They also serve as versatile building blocks for the synthesis of bioactive molecules, functional materials, and other heterocyclic compounds. , In addition, 1,2-diketones have been used as photosensitive agents, photoinitiators, and corrosion inhibitors . With respect to highly reactive electrophiles and dienophiles, 1,4-enediones also play a crucial role in the construction of complex molecules .…”

Aerobic Oxidative Dehydrogenation of Ketones to 1,4-Enediones

“…1,4-Enediones constitute a privileged structural motif of many bioactive natural products and pharmaceuticals (Figure ). 1,4-Enediones also serve as versatile precursors in the construction of various heterocycles such as furans, thiophenes, pyrroles, pyrazines, and indolizines . In addition, by virtue of their distinctive electrophilicity and electron affinity, they have been used as highly reactive electrophiles and dienophiles to construct complex molecules .…”