A modular synthesis of chiral aminoindanol-derived imidazolium salts

A modular synthesis of N-substituted chiral imidazolium salts derived from (1R,2S)-(+)-1-amino-2-inclanol is described. A wide range of amines are amenable to late stage introduction of the N-substituent to Provide N-aryl, N-alkyl, and N-amino imidazolium salts, which serve as precursors to chiral N-heterocyclic Carbenes (NHCs). A multi-gram synthesis of the N-mesityl derivative provides an important imidazolium salt for ongoing studies aimed at the development and understanding of NHC-catalyzed annulations. Critical to the success of this synthetic Strategy is a chemoselective alkylation, 6-exo-tet ring Closure of a formamide onto an epoxide, and a heterocyclic interconversion strategy. (C) 2008 Elsevier Ltd. All rights reserved.