Metal-Dependent Reactions of Bulky Metal(II) Amides M[N(SiMe₃)₂]₂ with 3,3′-Disubstituted Binaphthols (HO)₂C₂₀H₁₀(SiR₃)₂-3,3′: Selective Conversion of One Equivalent −OH Group to a Silyl Ether −OSiMe₃

Abstract

The outcome of the reaction of the bulky metal(II) amides M[N(SiMe3)2]2. nTHF (M = Be, Zn, Ge, Sn, n = 0; M = Mg, Ca, n = 2) with (R)-3,3'-bis(trimethylsilyl)-1,1'-bi-2,2'-naphthol ((R)-1) or (S)-3,3'-bis(dimethylphenylsilyl)-1,1'-bi-2,2'-naphthol ((S)-9) depends on the identity of the metal and the nature of the 3,3'-substituents. When M = Be, Zn, or Ge, these amides serve as useful silylation agents that convert only one of the equivalent hydroxyl groups of the binaphthol (R)-1 to a trimethylsilyl ether, whereas the reactions of (R)-1 with the Mg, Ca, or Sn amides generate a polynuclear complex. The reaction pathway for these interconversions was qualitatively monitored using NMR ((1)H and (9)Be) spectroscopy. Treatment of Ge[N(SiMe3)2] 2 with (S)-9 yields both a silyl ether and the chelated germanium(II) binaphthoxide (S)-[Ge{O2C20H10(SiMe2Ph)2-3,3'}{NH3}], which was structurally characterized.

Water and Ammonia Complexes of Germanium(II) Dications

“…Furthermore, the calculated GeÀN bond of 2.0988 is consistent with that reported for the only structure with a Ge II ÀNH 3 linkage (2.093(4)-2.107(4) ), which was obtained unexpectedly from the decomposition of a Ge II -N(SiMe 3 ) 2 precursor. [42,43] The computational data in Table 1 demonstrate that 4' has a much stronger Ge À E bond than 2', as would be anticipated on the basis of relative basicities of NH 3 and OH 2 . Furthermore, the bonds in the deprotonated models 3 and 5' are considerably stronger than are those of the corresponding dicationic adducts.…”

(N,N,N′,N′-Tetramethylethylenediamine-κN)bis(2,4,6-trimethylphenolato-κO)germanium(II)

“…The financial support of the Ministry of Education and Science, Youth and Sport of Ukraine, is gratefully acknowledged. Wetherby et al, 2008;Zemlyansky et al, 2003). A dimeric crystal structure of this type, [Ge(2,4,6-Me 3 C 6 H 2 O) 2 ] 2 , without use of a tertiary amine as a stabilizer was synthesized (Weinert et al, 2003).…”

“…For the synthesis and chemistry of aryloxygermylene-amine complexes, see: Bonnefille et al (2006). For related compounds, see: Huang et al (2009); Leung et al (2007); Seigi & Hoffman (1996); Weinert et al (2003); Wetherby et al (2008); Zemlyansky et al (2003). Table 1 Selected bond lengths (Å ).…”

Low‐Coordinate Germanium(II) Centers Within Distorted Axially Chiral Seven‐Membered Chelates: Stereo‐ and Enantioselective Cycloadditions

“…[7][8][9] We envisioned that a sevenmembered N-heterocyclic germylene containing an N,N'-bis(trimethylsilyl)-2,2'-diamino-6,6'-dimethylbiphenyl (LH 2 ) unit would engender a germanium center with relatively high Lewis acidity. Indeed, a number of N-and O-heterocyclic germylenes of larger ring size form adducts with Lewis donors, [10,11] however, their reactivity was not explored. Indeed, a number of N-and O-heterocyclic germylenes of larger ring size form adducts with Lewis donors, [10,11] however, their reactivity was not explored.…”