Enantioselective Intramolecular Carbene C–H Insertion Catalyzed by a Chiral Iridium(III) Complex of <i>D</i>₄-Symmetric Porphyrin Ligand

Abstract

The synthesis of iridium(III) complexes containing bulky porphyrin ligands is described. The chiral iridium(III) complex of the D4-symmetric Halterman porphyrin ligand [Ir((+)-D4-Por)Me(L)] (L = solvent) is an effective catalyst for enantioselective intramolecular carbene insertion into saturated C–H bonds of α-diazoesters, giving the corresponding cis-β-lactones in good isolated yields (up to 87%), excellent stereoselectivities (cis products exclusively), and good enantioselectivities (up to 78% ee).