Asymmetric organocatalytic anthrone additions to activated alkenes
作者:Alex Zea、Andrea-Nekane R. Alba、Natalia Bravo、Albert Moyano、Ramon Rios
DOI:10.1016/j.tet.2011.02.032
日期:2011.4
Asymmetric organocatalyticadditions of anthrones to activated alkenes are discussed. The reaction between anthrone or dithranol and α,β-unsaturated aldehydes is catalyzed by diphenylprolinol trimethylsilyl ether in toluene at −40 °C, giving the Michael adducts with good yields and enantioselectivities. Bifunctional amino-thioureas efficiently catalyze the additions of anthrones to both nitroalkenes and maleimides
Enantioselective Diels–Alder reaction of anthrone and maleimide catalyzed by a simple chiral tertiary amine
作者:Jian-Fei Bai、Yun-Long Guo、Lin Peng、Li-Na Jia、Xiao-Ying Xu、Li-Xin Wang
DOI:10.1016/j.tet.2012.11.011
日期:2013.1
Simple chiral tertiary amines with a special imide skeleton were first successfully applied to catalyze the enantioselective D–A reaction of anthrone and maleimides in excellent yields (up to 96%) and enantioselectivities (up to 95% ee).
A chiral analog of the bicyclic guanidine TBD: synthesis, structure and Brønsted base catalysis
作者:Mariano Goldberg、Denis Sartakov、Jan W Bats、Michael Bolte、Michael W Göbel
DOI:10.3762/bjoc.12.176
日期:——
catalyzes Diels-Alderreactions of anthrones and maleimides (25-30% ee). It also promotes as a strong Bronsted base the retro-aldol reaction of some cycloadducts with kinetic resolution of the enantiomers. In three cases, the retro-aldol products (48-83% ee) could be recrystallized to high enantiopurity (>/=95% ee). The absolute configuration of several compounds is supported by anomalous X-ray diffraction