The reaction of a cis â folded organocobalt derivative with a salen-type ligand, 1, isolated as racemic compound of ¢ and ¤ enantiomers, with enantiomerically pure R-L amino acids is reported. The reaction between racemic 1 and L-tyrosine afforded a mixture of the two diastereoisomers ¢-2 and ¤-2, which could be separated by fractional crystallization owing to the lower solubility of ¢-2. The absolute configuration of the two diastereomers was unequivocally assigned from the X-ray structure, using the known absolute configuration of the asymmetric carbon of the amino acid as internal reference. The reaction of racemic 1 with trans-4-hydroxy-L-proline afforded only the diastereoisomer with a ¢ configuration of the tetradentate ligand, as proved by X-ray diffractometric analysis.
Titolo: | Synthesis, Characterization, and Solution Behavior of Optically Active cis beta Organocobalt Salen_Complexes with L-Amino Acids. |
Autori: | |
Data di pubblicazione: | 2004 |
Rivista: | |
Abstract: | The reaction of a cis â folded organocobalt derivative with a salen-type ligand, 1, isolated as racemic compound of ¢ and ¤ enantiomers, with enantiomerically pure R-L amino acids is reported. The reaction between racemic 1 and L-tyrosine afforded a mixture of the two diastereoisomers ¢-2 and ¤-2, which could be separated by fractional crystallization owing to the lower solubility of ¢-2. The absolute configuration of the two diastereomers was unequivocally assigned from the X-ray structure, using the known absolute configuration of the asymmetric carbon of the amino acid as internal reference. The reaction of racemic 1 with trans-4-hydroxy-L-proline afforded only the diastereoisomer with a ¢ configuration of the tetradentate ligand, as proved by X-ray diffractometric analysis. |
Handle: | http://hdl.handle.net/11368/1699948 |
Digital Object Identifier (DOI): | http://dx.doi.org/10.1021/ic035059w |
Appare nelle tipologie: | 1.1 Articolo in Rivista |