Diels-Alder and Ene Reactions of the Stannaethene Me2Sn=C(SiMe3)2: Dienophilic and Enophilic Behaviour of Ethenes Me2E=C(SiMe3)2 (E=Si, Ge, Sn)

Abstract

An analogy to carbon has been established for the reported unsaturated compounds Me2Sn=C(SiMe3)2, Me2Ge=C(SiMe3)2 and Me2Si=C(SiMe3)2 in the study of their dieno- and enophilicity. The Diels–Alder and ene reactions of Me2E=(SiMe3)2 (E = Sn, Ge or Si) with butadienes and propenes take place both regioselectively and stereoselectively and are governed by electronic and steric effects. The trend towards ene reaction decreases at the cost of [4+2] cycloaddition in the order sila-, stanna-, germaethene.