Bis(oxazoline)\nIron Complexes Enable Tuning of Lewis\nAcidity for Catalytic Carbonyl–Olefin Metathesis

Carbonyl–olefin metathesis reactions are powerful\ntransformations\nfor carbon–carbon bond formation. Despite recent progress,\nlimitations exist that hamper the synthetic generality of the reported\napproaches. Catalytic systems that will enable tuning of their Lewis\nacidity and consequently the selective activation of specific substrate\nclasses are expected to greatly enhance the current scope. We herein\nreport the development of cationic iron-bis(oxazoline) complexes as\npowerful catalysts that enable the alteration of Lewis acidity to\nefficiently convert substrate types that were previously found to\nbe incompatible with existing catalytic systems in carbonyl–olefin\nring-closing metathesis.