2,3-Dihydroimidazo1,2-apyridines:  A New Class of Enantioselective Acyl Transfer Catalysts and Their Use in Kinetic Resolution of Alcohols

The long-known, but previously unexplored 2,3-dihydroimidazo1,2-apyridine (DHIP) has been shown to be a competent acyl transfer catalyst. Its chiral 2-phenyl derivatives obtainable in two steps from commercially available starting materials have proved to be effective acylation catalysts, giving high levels of enantioselectivity (s = 20-85) in kinetic resolution of secondary benzylic alcohols. A transition state model explaining the observed selectivity has been proposed.