Synthesis of 2-[2-(Diphenylphosphino)ferrocenyl]oxazoline Ligands

Abstract

Dehydration of β-hydroxy amide 5, generated by condensation of (S)-(+)-valinol with ferrocenoyl chloride, gives (S)-2-ferrocenyl-4-(1-methylethyl)oxazoline 7. This is employed in the synthesis of (S)-2-[(S)-2-(diphenylphosphino)ferrocenyl]-4-(1-methylethyl)oxazoline 8 and the corresponding (S)-(R) diastereoisomer 9; a complementary pair of ligands for use in asymmetric catalysis.