New digermylalkenes and digermylalkynes: [1,3]-chlorine shifts in organogermanium chemistry?

摘要

Dimesitylfluoro(trichloromethyl)germane (1) has been synthesized from difluorodimesitylgermane, chloroform, and n-butyllithium. Addition of n-butyllithium to compound 1 gave the lithium carbenoid MeS2(F)Ge-C(Li)Cl-2 (2), which behaves as a synthetic equivalent of the C-dichlorogermene MeS2Ge=CCL2 (5). Warming 2 to room temperature afforded the 1,2-digermylalkene Mes(2)(F)Ge-CCl=CCl-Ge-(CL)MeS2 (6) possibly by an unprecedented [1,3]-Cl shift from the transient germene MeS2(F)Ge-CCl2-CCl=GeMeS2 (8). Addition of tert-butyllithium to 6 gave bis(chlorogermyl)alkyne MeS2(Cl)Ge-C C-Ge(Cl)MeS2 (9) probably via a 3-chloro-l-germaallene/(chlorogermyl)alkyne rearrangement.