Enantioselective π-Complexation. Synthesis of Enantiomerically Pure Planar Chiral Ruthenocenes

Autor:	Karin Bücken, Ulli Englert, Ulrich Koelle
Rok vydání:	1996
Předmět:	Chiral auxiliary Chemistry Ligand Organic Chemistry Enantioselective synthesis Diastereomer Absolute configuration Asymmetric induction Medicinal chemistry Inorganic Chemistry chemistry.chemical_compound Physical and Theoretical Chemistry Enantiomeric excess Fulvene
Zdroj:	Organometallics. 15:1376-1383
ISSN:	1520-6041 0276-7333
DOI:	10.1021/om950736i
Popis:	Reaction of half-sandwich complexes Cp*RuL2ch, featuring a chiral auxiliary ligand L2ch, with prochiral cyclopentadienides Cppc- gave enantiomerically pure (>95% ee) or enriched ruthenocenes Cp*RuCppc 4. For the chiral auxiliary L2ch were tested a pyridyloxazoline (ref 15), the diolefin nopadiene (ref 16), and the amino acids methionine and proline, which form relatively labile complexes with the Ru(II) fragment Cp*Ru+. For the prochiral cyclopentadienide CppcLi, Li derivatives of 1- tert-butyl-3-methylcyclopentadienide, 1-tert-butylindenyl, and 1- tert-butyl-3-benzylindenyl were used. Determination of enantiomeric excess was achieved through a derivatization procedure generating fulvene cation complexes [CppcRuC5Me4CH2]+ (5), which, after the addition of (S)-α-phenylethylamine, yield mixtures of diastereoisomers CppcRuC5H4CH2NHCH(Me)Ph (6). The absolute configuration of 4c (Cppc = 1-tert-butyl-3-benzylindenyl) was determined by X-ray structure analysis of the respective fulvene salt. Asymmetric induction...
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::74d8ddc95a8e0dd8785fb43dccea776b https://doi.org/10.1021/om950736i Zobrazit plný text záznamu