Le rearrangement de claisen en series siliciee et germaniee: silaethylene et germaethylene

Thermolysis of silicon and germanium isologues of allyl aryl ethers via transient metal π-bonded intermediates leads to aromatic Claisen-type rearrangement. Para-Claisen type reaction is not observed when the aromatic ring is ortho-disubstituted. In that case the Cope rearrangement is replaced by a radical process. The Claisen rearrangement leads to new oxametallacylohexanes by intramolecular trapping of the metal-carbon double-bond, when the homolytic process gives rise to new oxametallacycloheptanes.