Synthesis of Optically Active Ferrocene Analogues of Salicylic Acid Derivatives and Rhodium(II)-Catalyzed Asymmetric Intramolecular C–H Insertion ofα-Diazoβ-Keto Esters Using New Chiral Carboxylato Ligands
Through a double cyclization triplet carbonylcarbenes add smoothly to double bonds in the δ and ε position, but do not react intramolecularly with C-H bonds (see scheme). The addition reaction fails if the keto group is replaced with an ester group.