Bifunctional Amine-Squaramides as Organocatalysts in Michael/Hemiketalization Reactions of β,γ-Unsaturated α-Ketoesters and α,β-Unsaturated Ketones with 4-Hydroxycoumarins
The catalytic efficiency of various amine-squaramides was tested in Michael/hemiketalization reactions of 4-hydroxycoumarines with two types of enones. Tertiary amine-squaramide organocatalysts afforded the best results regarding both activity and enantio
A library of pyranocoumarin derivatives via a one-pot three-component hetero Diels-Alder reaction [1]
A hetero Diels-Alder reaction with inverse electron demand between 4-hydroxycoumarin, aromatic alde, hydes and electron-rich alkenes yielded a multitude of 2,4-disubstituted 3,4-dihydropyranocoumarins. This route opened an easy access to coumarin anticoagulants and provided a library of pyranocoumarin derivatives.
Cravotto,Nano,Palmisano,Pilati,Tagliapietra
p. 965 - 971
(2007/10/03)
STUDIES ON THE CONDENSATION PRODUCTS OF SOME α, β -UNSATURATED CARBONYL COMPOUNDS WITH 4-HYDROXYCOUMARIN
The base catalysed condensation products of mesityl oxide and benzalacetone with 4-hydroxycoumarin have been studied.The reported structures (III) and (IX) of two condesation products are revised as (V) and (X) respectively.Chemicxal transformations of (V