Iron-disilyl-complex-induced activation of carbonyl compounds in the deoxygenative formation of iron-carbene complexes.

Even though transition-metal-carbene complexes occupy an important position in modern materials science, many synthetic methods for the synthesis of transition-metal carbenes rely on the use of diazomethane reagents or the incorporation of alkyl ligands followed by α-H elimination. Herein, we report that carbonyl compounds such as ketones and aldehydes can function as carbene sources via C=O bond cleavage when treated with an iron-disilyl complex with a siloxane backbone. The reaction of cyclopropenones with this iron-disilyl complex produced isolable carbene complexes, whose structures were exhaustively characterized. Similar reaction of iron-disilyl complex with DMF gave rise to the production of zwitterionic iron complex as an isolable complex, then it was converted into carbene complex upon heating. Detailed reaction mechanism for the formation of iron-carbene complexes by the reaction of iron-disilyl complex with carbonyl compounds through the zwitterionic species was demonstrated based on experimental and theoretical investigation.