Co(III) catalysed asymmetric ring-opening of epichlorohydrin by salicylaldehyde derivatives: reversal of enantioselectivity and rate acceleration on addition of AlCl_3

Synthesis and Characterization of Multifunctional Chiral Schiff Base Derivatives

“…The ring opening reaction of epichlorohydrin was carried out with 2,4-dihydroxybenzaldehyde in the presence of Jacobsen's Co(III) salen catalyst [4,9]. We obtained a single product arising from selective reaction at the 4-OH group (Scheme 1).…”

“…Melting points were recorded with an Electrothermal digital melting point apparatus. The Co(III) salen catalyst [9] and compound 1 were prepared according to the literature method [4].…”

“…Enantiopure α-alkoxy and α-aryloxy alcohols are valuable target molecules for asymmetric synthesis because of their role as key synthetic intermediates in a variety of pharmaceutically important compounds [1][2][3]. Recently, we reported the first ring-opening of epichlorohydrin with salicylaldehyde derivatives in the presence of Jacobsen's Co(III) salen catalyst [4]. The final ring-opened product is a multifunctional aldehyde 1 containing a stereocenter in addition to the alkyl halide and alcohol functional groups.…”