Petits cycles à liaison germanium‐azote: Synthèse et réactivité de germa‐2 azolidines, germa‐2 azétidines, germa‐2 aziridines. Caractérisation de germa‐imines: Nouveaux intermédiaires à germanium π‐lié

Abstract

Abstract Germylated 3‐, 4‐ or 5‐membered heterocycles containing a Ge‐N bond are synthetized by direct aminolysis (followed by dehydrochlorination) or by action of amino dilithium compounds on germylated dichlorides of the general structure magnified image . The preparations of these new dichlorides are also described. 2‐Germaazolidines are thermally stable. 2‐Germaazétidines decompose at moderate temperature, through a β‐elimination process, to give germa‐imine magnified image and alkene. 2‐Germaaziridines, likely in equilibrium with an open zwitter ionic form, readily decompose through an α‐elimination process, to lead to the corresponding germylene and imine. The reactivity of these heterocycles has been considered from specific reactions of the Ge‐N bond: cleavage by protic species, LiAlH 4 reduction or addition on insaturated compounds (CS 2 , PhNCO), the last reaction leading to ring expansion.