Calixarene-based highly efficient primary amine–thiourea organocatalysts for asymmetric Michael addition of aldehydes to nitrostyrenes
作者:Mustafa Durmaz、Abdulkadir Sirit
DOI:10.1080/10610278.2013.773331
日期:2013.5.1
The synthesis of calix[4]arene-based chiral bifunctional primary amine–thioureacatalysts has been described from p-tert-butylcalix[4]arene for the first time. The calix[4]arene-based catalysts were successfully applied to promote Michael addition of aldehydes with nitroalkenes affording preferentially the (R)- or (S)-adducts in high yields (up to 95%) and excellent enantioselectivities (up to 99%
Enantioselective Michael addition of aldehydes to nitroolefins catalyzed by pyrrolidine-HOBt
作者:Togapur Pavan Kumar、Mohammad Abdul Sattar、Sthanikam Siva Prasad、Kothapalli Haribabu、Cirandur Suresh Reddy
DOI:10.1016/j.tetasy.2017.02.005
日期:2017.3
The oxytriazole catalyst "pyrrolidine-HOBt" developed for asymmetric Michael addition of cyclohexanone to nitroolefins is now evaluated for the asymmetric Michael addition of aldehydes to nitroolefins under similar reaction conditions. The results of this study indicate that, the oxytriazole catalyst "pyrrolidine-HOBt" is equally effective in promoting the Michael addition of aldehydes to nitroolefins on employing benzoic acid as an additive. The desired products, gamma-nitrocarbonyl compounds were obtained in good yields and high enantioselectivities. (C) 2017 Elsevier Ltd. All rights reserved.