Synthesis of Tetrasubstituted Furans through One-Pot Formal [3 + 2] Cycloaddition Utilizing [1,2]-Phospha-Brook Rearrangement
Azusa Kondoh, Kohei Aita, Sho Ishikawa, Masahiro Terada
Abstract
An efficient method for the synthesis of tetrasubstituted furans was developed by utilizing the [1,2]-phospha-Brook rearrangement under Brønsted base catalysis. The two-step one-pot formal [3 + 2] cycloaddition involves the nucleophilic addition of a propargyl anion, which is catalytically generated through the [1,2]-phospha-Brook rearrangement, to an aldehyde and the subsequent intramolecular cyclization mediated by N-iodosuccinimide to provide 2,4,5-trisubstituted-3-iodofurans. The present method with readily available substrates provides new access to a wide range of well-organized tetrasubstituted furans.
Topics & Concepts
CycloadditionChemistryPropargylNucleophileAldehydeIntramolecular forceCombinatorial chemistryCatalysisBrønsted–Lowry acid–base theoryMedicinal chemistryStereochemistryOrganic chemistryCatalytic Alkyne ReactionsCatalytic C–H Functionalization MethodsCyclopropane Reaction Mechanisms