Per-6-amino-β-cyclodextrin catalyzed asymmetric Michael addition of nitromethane and thiols to chalcones in water
作者:Palaniswamy Suresh、Kasi Pitchumani
DOI:10.1016/j.tetasy.2008.08.014
日期:2008.9
An environmentally benign and enantioselective Michaeladdition of nitromethane/thiols to trans-chalcone catalyzed by per-6-amino-β-cyclodextrin (per-6-ABCD) is carried out in water at room temperature with good yield and enantiomeric excess. The catalyst is recovered and reused without loss in its activity.
Primary Amine-Thioureas with Improved Catalytic Properties for “Difficult” Michael Reactions: Efficient Organocatalytic Syntheses of (S)-Baclofen, (R)-Baclofen and (S)-Phenibut
作者:Michail Tsakos、Christoforos G. Kokotos、George Kokotos
DOI:10.1002/adsc.201100636
日期:2012.3
Among the class of primary amine‐thioureas based on tert‐butyl esters of α‐amino acids, the most efficient organocatalyst for “difficult” Michaelreactions was identified. The derivative based on (S)‐di‐tert‐butyl aspartate and (1R,2R)‐diphenylethylenediamine provided the products of the reaction between aryl methyl ketones and nitroolefins in excellent yields and enantioselectivities. In addition