Nonphotochemical synthesis of a base-free silyl(silylene)iron complex and its reaction with CO: Another direct evidence for reversible 1,2- and 1,3-group migrations

A base-free silyl(silylene)iron complex 1, which had been originally synthesized by a photochemical method, was prepared in higher yield by a newly developed thermal method. Reaction of this silyl(silylene)iron complex 1 with CO at 80°C cleanly produced a mixture of two isomeric disilanyliron complexes 6 and 6′ via 1,3-group migrations followed by 1,2-silyl migration. Oppositely, each of disilanyl complexes 6 and 6' reproduced the silyl(silylene)iron complex 1 with a release of CO almost quantitatively at room temperature by irradiation with a fluorescent lamp.