Convenient syntheses, based on cyclohexene oxide, of ligands that are highly preorganised for metal ion size-based selectivity

Abstract

Cyclohexene oxide reacts with strong diastereoselectivity with polyamines to give good yields of well defined crystalline products where only one, or sometimes two, pendant groups are present, such as N-(2-hydroxycyclohexyl)cyclen or DL-1,7-bis(2-hydroxycyclohexyl)-1,4,7-triazaheptane, which as ligands show strong and predictable preferences for smaller metal ions.