Michael Additions of Aldehydes and Ketones to β‐Nitrostyrenes in an Ionic Liquid

Michael additions of different aldehydes and ketones to β‐nitrostyrene and 2‐(β‐nitrovinyl)thiophene in 1‐butyl‐3‐methylimidazolium hexafluorophosphate ([bmim]PF6) were studied. β‐Nitrostyrene was a better acceptor than 2‐(β‐nitrovinyl)thiophene, in terms of both reactivity and selectivity. Aldehydes proved to be better donors than ketones, which were themselves better than β‐diketones. L‐proline proved to be the best catalyst among seven organocatalysts tested. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)