Synthesis of New Asymmetric Phosphonylated Thiazolines and their Use in Olefination Reactions

Abstract

N-(2-Hydroxyalkyl)-2-phosphonoethanethioamides were prepared from a readily accessible phosphonodithioacetate and commercial chiral β-amino alcohols. Taking advantage of both the presence of the hydroxy group (nucleofuge) and of the C=S (nucleophile) in the same molecule, we obtained new chiral phosphonylated thiazolines by an intramolecular cyclisation using the Mitsunobu procedure. These thiazoline-phosphonates were then involved in Horner-Wadsworth-Emmons reaction to give asymmetric vinylic thiazolines.