Synthesis of Functionalized Heteroleptic Germylene Alkoxides

Abstract

AbstractN‐coordinated Ge(II) alkoxides L1(tBuO)Ge (1), L2(tBuO)Ge (2) and [L2(OtBu)Ge ⋅ BH3] (4) were prepared. Effect of either chelating ligands L1 and L2 or Ge→B interaction on strength of the Ge−OtBu bond was studied by insertion reaction of PhNCO. As a result, the Ge(II) carbamate L2{[(tBuO)OC](Ph)N}Ge (3) was isolated. Alcoholysis exchange reactions of 1 and 2 with substituted phenols were studied to find an easy synthetic protocol for a synthesis of functionalized Ge(II) alkoxides. Reactions yielded Ge(II) alkoxides L1,2(2‐Br−C6H4O)Ge (5 for L1, 8 for L2), L1,2(2‐MeNH−C6H4O)Ge (6 for L1, 9 for L2), L1,2(2‐Ph2P−C6H4O)Ge (7 for L1, 10 for L2), L2(2‐Br‐3‐OH−C6H3O)Ge (11) and L2(2‐NC5H4O)Ge (12) containing the additional polar groups Y (Y=Br, MeNH, PPh2, OH or N). Finally, phosphane decorated Ge(II) alkoxides 7 and 10 were tested as suitable ligands in reactions with (COD)W(CO)4 and BH3. As a consequence, new complexes [(κ2‐7)W(CO)4] (13) and [L1(2‐Ph2P ⋅ {BH3}‐C6H4O)Ge ⋅ {BH3}] (14) were isolated. All compounds were characterized by NMR and IR spectroscopy, and compounds 3, 4, 9 and 11 were additionally characterized by X‐ray diffraction analysis.