Synthesis of 2,4,5-Trisubstituted 3-Fluorofurans via Sequential Iodocyclization and Cross-Coupling of gem-Difluorohomopropargyl Alcohols

Abstract

The iodocyclization of gem-difluorohomoallenyl and gem-difluorohomopropargyl alcohols with I₂ and ICl, respectively, produced the corresponding fluorinated iodofuran analogues in good yields. The iodo substituent in fluorinated 4-iodofurans was utilized as a synthetic handle to prepare multi-substituted 3-fluorofurans using a Suzuki cross-coupling reaction. The yields of both iodocyclization of gem-difluorohomopropargyl alcohol and subsequent Suzuki coupling were dramatically enhanced by microwave irradiation.