Regioselectivities in Fe(III)-catalyzed Cycloisomerization Reactions of gamma-Allenyl Alcohols

摘要

Iron-catalyzed intramolecular hydroalkoxylation reactions of allenes were performed to provide various tetrahydrofurans by regioselective 5-exo cyclization pathway, as the Lewis acidic activation of Fe(III) salts toward unsaturated C-C bonds, allenes and alkenes. Cyclohexyl substituted allenes especially isomerized to dienes at a rapid rate, which underwent a competing 6-endo cyclization mode. The plausible mechanism was presented by experimental results of the reaction intermediates and computational study of Fe-allene and Fe-diene complexes.