The Modular Synthesis of Chiral N-Heterocyclic Carbene Precursors

A series of chiral N-heterocyclic carbene precursors based on the dihydroimidazole framework were prepared from easily available chiral amines. The sequential attachment of these amines and mesitylamine to chloroacetyl chloride followed by reduction and subsequent ring closure gave the desired dihydroimidazolium salts in good yield.