Microwave-Assisted Organocatalytic Enantioselective Intramolecular aza-Michael Reaction with α,β-Unsaturated Ketones
作者:Santos Fustero、Carlos del Pozo、Cristina Mulet、Rubén Lazaro、María Sánchez-Roselló
DOI:10.1002/chem.201101292
日期:2011.12.9
AbstractAn organocatalytic enantioselective intramolecular aza‐Michael reaction of carbamates bearing conjugated ketones as Michael acceptors is described. By using 9‐amino‐9‐deoxy‐epi‐hydroquinine as the catalyst and pentafluoropropionic acid as a co‐catalyst, a series of piperidines, pyrrolidines, and the corresponding benzo‐fused derivatives (indolines, isoindolines, tetrahydroquinolines, and tetrahydroisoquinolines) can be obtained in excellent yields and enantioselectivities. In addition, the use of microwave irradiation at 60 °C improves the efficiency of the process giving rise to the final products with comparable yields and enantiomeric excesses. Some mechanistic insights are also considered.