Synthesis, stereochemistry and decomplexation of (η-arene)(η-cyclopentadienyl) iron(II) hexafluorophosphate complexes containing amino acid side chains. A route to N-arylamino acids
摘要:
[(eta-Substituted arene)(eta-cyclopentadienyl)Fe][PF6] complexes with amino acid side chains on the arene ring have been prepared by reaction of [(eta-haloarene)(eta-cyclopentadienyl)Fe][PF6] complexes with amino acids and amino acid eaters under various conditions. Evidence is presented from H-1-and C-13-NMR spectroscopy for the existence of conformational isomers resulting from restricted rotation about the arene-nitrogen bond. Where a chlorine substituent is also present in the complexed arene, diastereoisomers can be separated by column chromatography. Decomplexation of the complexes is reported in strongly basic media or using 1,8-phenanthroline in light-catalysed reactions offering a new route to N-arylamino acids. (C) 1997 Elsevier Science S.A.