A novel and recyclable catalyst, a C3-symmetrical cinchonine-squaramide, has been developed for the asymmetric Michaeladdition of 1,3-dicarbonylcompounds to nitroalkenes. When using only 1 mol% of catalyst 1a for the reaction, high reaction yields with excellent enantioselectivities and diastereoselectivities (up to 96% yield,>99% ee,>99:1 dr) were achieved, in which the results for cyclic keto esters
Synthesis of Chiral Tertiary Amine–Thioureas Based on Spirobiindane and Application in Catalytic Asymmetric Michael Addition Reaction
作者:Zhao Han、Xufeng Lin
DOI:10.1055/s-0039-1691643
日期:2020.4
A series of novel chiral bifunctional tertiary amine–thioureas based on spirobiindane were designed and synthesized as organocatalysts. One of these catalysts was shown to promote the asymmetric Michael addition reaction of 1,3-diphenylpropane-1,3-dione to nitroolefins, affording the desired products in good yields (up to 95%) and enantioselectivities (up to 98% ee).
Disclosed is a process of carrying out a Michael reaction with recovery of the catalyst, where a compound of formula (1):
is reacted with a compound of formula (2):
in the presence of a catalyst of formula (4):
where the compounds of formulae (1) and (2) undergo a Michael reaction.
Development of Mefloquine-Based Bifunctional Secondary Amine Organocatalysts for Enantioselective Michael and Friedel–Crafts Reactions
作者:Dawid J. Kucharski、Radosław Suchanek、Rafał Kowalczyk、Przemysław J. Boratyński
DOI:10.1021/acs.joc.3c01791
日期:2024.1.5
The chiral framework based on 11-aminomefloquine has been utilized for the first time to construct bifunctional organocatalysts. These catalysts demonstrate high enantioselectivity in both Michaeladditions and Friedel–Crafts reactions across a variety of substrates, achieving up to >99% ee. The distinctive feature is the incorporation of a secondary amine group, offering unique tight hydrogen-bonding