Spirocyclic zwitterionic lambda5Si-silicates with two bidentate ligands derived from alpha-amino acids or alpha-hydroxycarboxylic acids: synthesis, structure, and stereodynamics.
A series of zwitterionic lambda(5)Si-silicates with a (2,2,6,6-tetramethylpiperidinio)methyl group and two identical bidentate ligands derived from glycine, (S)-alanine, (S)-phenylalanine, glycolic acid, (S)-lactic acid, (S)-3-phenyllactic acid, or (S)-mandelic acid were synthesized and structurally characterized (solution and solid-state NMR spectroscopy; single-crystal X-ray diffraction). The chiral lambda(5)Si-silicates with ligands derived from optically active alpha-amino acids or alpha-hydroxycarboxylic acids were isolated as enantiomerically and diastereomerically pure compounds that undergo a (Lambda)/(Delta)-epimerization in solution.
Tacke
Reinhold
R
Institut für Anorganische Chemie, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany. r.tacke@mail.uni-wuerzburg.de
Bertermann
Rüdiger
R
Burschka
Christian
C
Dragota
Simona
S
Penka
Martin
M
Richter
Ingo
I
D000596:Amino Acids / Q000737:chemistry*; D002264:Carboxylic Acids / Q000737:chemistry*; D007477:Ions; D007700:Kinetics; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D015394:Molecular Structure; D017640:Silicates / Q000138:chemical synthesis / Q000737:chemistry*; D013237:Stereoisomerism
D000596:Amino Acids; D002264:Carboxylic Acids; D007477:Ions; D008024:Ligands; D017640:Silicates