Preparation of germatranyl triflates: reactions of germatranes N(CH2CHRO)3X (X=Br, OTf, OSiMe3; R=H, Me) with lithium reagents

New germatranes N(CH2CHRO)3GeOTf (4a, R=H; 4b, R=Me) were prepared in quantitative yield by treatment of N(CH2CHRO)3GeOSiMe3 (2a and 2b), with Me3SiOTf. The reactions of germatranes N(CH2CHRO)3GeX [3a, X=Br, R=H; 4a, X=OSO2CF3, R=H; 4b, X=OSO2CF3, R=Me; 2a, X=OSiMe3, R=H; 2b, X=OSiMe3, R=Me] with LiY reagents were studied. A series of germatranes N(CH2CHRO)3GeY [5a, R=H, Y=Ind (indenyl); 5b, R=Me, Y=Ind; 6a, R=H, Y=N(SiMe3)2; 6b, R=Me, Y=N(SiMe3)2; 7a, R=H, Y=Cp (cyclopentadienyl); 7b, R=Me, Y=Cp; 8a, R=H, Y=Flu (fluorenyl); 9a, R=H, Y=t-Bu] were obtained by nucleophilic substitution with the corresponding LiY reagent. Reactions of N(CH2CHMeO)3GeOSiMe3 (2b) and N(CH2CH2O)3GeBr (3a) with excess n-BuLi and of N(CH2CH2O)3GeOSiMe3 (2a) with excess LiNMe2 led to the formation of n-Bu4Ge and (Me2N)4Ge. The structures of new germatranes 4a, 4b, 6b and 7b were confirmed by NMR spectroscopy, mass spectrometry and elemental analyses.