1217974-53-2Relevant academic research and scientific papers
Highly enantioselective Michael Addition of α-Substituted Cyano Ketones to β,γ-unsaturated α-keto esters using bifunctional thiourea-tertiary amine catalysts: An easy access to chiral dihydropyrans
Zhao, Sheng-Li,Zheng, Chang-Wu,Wang, Hai-Feng,Zhao, Gang
supporting information; experimental part, p. 2811 - 2816 (2010/03/05)
An asymmetric Michael addition of α-substituted cyano ketones to β,γ-unsaturated α-keto esters to form chiral dihydropyrans catalyzed by a series of a-amino acid-derived thiourea-tertiary amines is presented. A novel tyrosine-derived thio-urea catalyst was identified as the optimal catalyst providing the desired product in 91-95% yields and with 90-96% ee at a low catalyst loading of 2.0mol%. The utility of the reaction was exempli-fied by facile conversion of the dihydropyran prod-uct into pharmaceutically useful dihydropyridine.
