Efficient carbene transfer reactivity mediated by Fe() complexes supported by bulky alkoxides

Herein we describe the stoichiometric and catalytic carbene-transfer reactivity of iron( ii ) alkoxide complexes with iodonium ylide precursors. Treatment of PhIC(CO 2 Me) 2 with styrene in the presence of catalytic amounts of several different Fe(OR) 2 (THF) 2 precursors results in efficient cyclopropanation for a variety of styrenes. Computational and reactivity studies suggest a novel remote metallocarbene/vinyl radical intermediate, Fe(OR) 2 (κ 2 -(O&z.dbd6;C(OMe)) 2 C), which could be responsible for the reactive nature of the catalyst. The reaction of Fe(OR) 2 (THF) 2 (OR = bulky alkoxide ligand) with PhIC(CO 2 Me) 2 results in the formation of reactive remote carbene/vinyl radical intermediate that undergoes facile cyclopropanation or dimerization.