%0 Generic %A Kaeobamrung, Juthanat %A Bode, Jeffrey W. %D 2009 %T Stereodivergency of Triazolium and Imidazolium-Derived NHCs for Catalytic, Enantioselective Cyclopentane Synthesis %U https://acs.figshare.com/articles/dataset/Stereodivergency_of_Triazolium_and_Imidazolium_Derived_NHCs_for_Catalytic_Enantioselective_Cyclopentane_Synthesis/2880874 %R 10.1021/ol802739d.s005 %2 https://ndownloader.figshare.com/files/4578766 %K enantioselectivity %K Catalytic %K demonstration %K stereodivergency %K NHC %K annulation %K aldehyde %K chiral imidazolium %K lactone %K achiral %K chiral structures %K carbene %K enone %K triazolium precatalysts %K hydroxy %K Enantioselective Cyclopentane Synthesis Chiral triazolium %K Triazolium %K entry %K Remarkably %K Stereodivergency %X Chiral triazolium- and imidazolium-derived N-heterocyclic carbene catalysts promote the direct annulation of α,β-unsaturated aldehydes and achiral α-hydroxy enones to afford cyclopentane-fused lactones with high enantioselectivity. Remarkably, otherwise structurally identical imidazolium and triazolium precatalysts afford different major products. These studies provide both an efficient entry to valuable chiral structures and a dramatic demonstration of stereodivergency of chiral imidazolium versus triazolium-derived N-heterocyclic carbene catalysts. %I ACS Publications