This Letter described the synthesis of the first diarylprolinol silyl ether-derived bifunctional thiourea organocatalysts. The catalysts were applied to the asymmetricMichaeladdition of aldehydes to nitroalkenes to give the desired adducts in good yields (up to 99%) with excellent enantioselectivities (up to 99% ee) and excellent diastereoselectivities (up to 99:1). The spatial placement of C-4 substituent
Peptoids, N‐substituted glycine oligomers, represent an important class of peptidomimetics that can fold into three‐dimensional structures in solution. Most of the folded peptoid structures, however, resemble helices, and this can limit their applications, specifically in asymmetric catalysis. In this work, for the first time, unique examples of pyrrolidine‐based β‐turn‐like peptoids are described
Ionic Liquid-Supported (ILS) (S)-Pyrrolidine Sulfonamide for Asymmetric Michael Addition Reactions of Aldehydes with Nitroolefins
作者:Emmy M. Omar、Kritanjali Dhungana、Allan D. Headley、Mohd Basyaruddin Abdul Rahman
DOI:10.2174/157017811795038395
日期:2011.3.1
supported (ILS) (S)-pyrrolidine sulfonamide organocatalyst (1c), which was developed earlier in our lab, has been applied to a wider range of Michaeladditionreaction, involving various aryl-substituted nitroolefins and a series of aldehydes. Catalyst 1c catalyzes Michaeladditions in which only 2 equivalents of aldehydes to each equivalent of nitroolefin are required. With 10 mol% of ILS catalyst
Di(methylimidazole)prolinol Silyl Ether Catalyzed Highly Michael Addition of Aldehydes to Nitroolefins in Water
作者:Jianbin Wu、Bukuo Ni、Allan D. Headley
DOI:10.1021/ol901204b
日期:2009.8.6
effective catalyst for the Michael reaction involving various nitroolefins and aldehydes in water. This design is based on the introduction of a hydrophilic group into the pyrrolidine side chain. This catalyst, di(methylimidazole)prolinol silyl ether in combination with sodium bicarbonate as additive effectively catalyzed the Michaeladdition of aldehydes to nitroolefins in water as solvent in high yields
Diarylprolinol Silyl Ether Salts as New, Efficient, Water-Soluble, and Recyclable Organocatalysts for the Asymmetric Michael Addition on Water
作者:Zilong Zheng、Benjamin L. Perkins、Bukuo Ni
DOI:10.1021/ja9093583
日期:2010.1.13
for the catalytic asymmetric Michaeladdition of aldehydes to nitroolefins on water has been developed and provided the Michael adducts in excellent diastereo- and enantioselectivities. A notable feature of these organocatalysts is that they can be recycled for more than six times without a significant loss of catalytic activity and stereochemical control. In addition, the synthetic procedure presented