Reactivity of Germene Mes₂GeCR₂ with Cumulative Unsaturation-Containing Compounds:  Synthesis of New Germanium Heterocycles

Abstract

Germene 1 reacts with the CO and CS double bonds respectively of phenylisocyanate and methylisothiocyanate by formal [2+2] cycloadditions, leading to four-membered ring derivatives 2 and 3 . With CS 2, dithiagermolane 11 and dithiadigermetane 12 are obtained; the first step of this reaction is probably a formal [2+2] cycloaddition between the Ge C and C S double bonds. With nitromethane, oxazadigermolidine 19 and fluorenone are obtained, the first step likely being a [2+3] cycloaddition between the Ge C double bond and the NO 2 moiety. Compounds 11 and 19 were characterized by X-ray diffraction analysis.