New approach to 1-(phenylethynyl)germatranes and 1-(phenylethynyl)-3,7,10-trimethylgermatrane. Reactions of 1-(phenylethynyl)germatrane with N-bromosuccinimide and bromine

Reaction of N(CH2CHRO)3GeBr (2a, b) with LiCCPh affords N(CH2CHRO)3GeCCPh (1a, b) (a, R=H; b, R=Me). Compound (1b) was also obtained by treatment of Cl3GeCCPh (3) with N(CH2CHMeOSnEt3)3 (4). (1a) reacts with N-bromosuccinimide to yield N(CH2CH2O)3GeC(Br)2C(O)Ph (5). Cis-N(CH2CH2O)3GeC(Br)C(Br)Ph (6) is formed by the reaction of 1a with Br2 in equivalent amounts. All compounds were characterized by 1H- and 13C-NMR spectroscopy and mass spectrometry. Single crystal structures of 1a and 6 were determined by X-ray diffraction studies.