Quaternary ammonium zinc- or tin-containing ionic liquids: water insensitive, recyclable catalysts for Diels–Alder reactions
Abstract
Synthetically important Diels–Alder reactions occur in high yield in novel Lewis acidic ambient temperature ionic liquids composed of choline chloride–MCl2 (1:2) (M = Zn or Sn). The liquids are not moisture-sensitive and after separation of the products they can be reused with no noticeable drop in activity.