Highlyenantioselective Michael addition of 1,3‐dicarbonyl compounds and nitromethane to 4‐oxo‐4‐arylbutenoates catalyzed by N,N′‐dioxide–Sc(OTf)3 complexes has been developed. Using 0.5–2 mol % catalyst loading, various α‐stereogenic esters were obtained regioselectively with excellent yields (up to 97 %) and enantioselectivities (up to >99 % ee). Moreover, the reaction performed well under nearly
Substrate-Controlled, One-Pot Synthesis: Access to Chiral Chroman-2-one and Polycyclic Derivatives
作者:Xue-Li Sun、Ying-Han Chen、Dan-Yang Zhu、Yan Zhang、Yan-Kai Liu
DOI:10.1021/acs.orglett.6b00160
日期:2016.2.19
appropriate choice of electrophiles, one-pot, multicomponent, enantioselective domino reactions have been realized which contain a five-step sequence and provide highly efficient access to potentially bioactive chroman-2-one derivatives as a single diastereoisomer with excellent enantioselectivities and in high yields. This new strategy could significantly improve the previous protocol by directly starting
Enantioselective conjugate addition of aliphatic thiols to divergently activated electron poor alkenes and dienes
作者:Rafał Kowalczyk、Aleksandra J. Wierzba、Przemysław J. Boratyński、Julia Bąkowicz
DOI:10.1016/j.tet.2014.06.035
日期:2014.9
Divergently activated double bonds in electron poor 4-oxo-butenoates and (2E,4E)-6-oxo-2,4-dienoates underwent stereoselective and regioselective addition of mercaptans catalyzed by simple Cinchona alkaloids. Application of quinine and quinidine afforded both enantiomers of the 1,4-adducts with respect to the ketone carbonyl group in ees of up to 80%. Single recrystallization of some adducts resulted
A useful Michael addition reaction using nitroalkanes as the nucleophile and 4-oxo-enoates as the Michael acceptor has been disclosed, and the reaction allows expedient access to functionalized chiral gamma-keto esters in high yields and excellent enantioselectivities (up to 98% ee), with a low catalyst loading.
Catalytic Conjugate Addition of Indoles to 4-Aryl-4-oxobut-2-enoates by FeCl<sub>3</sub>
作者:Xiaoxia Wang、Yaohong Zhang、Xiaohui Xiao、Xinsheng Li
DOI:10.1246/cl.2008.1284
日期:2008.12.5
The conjugate addition of indoles to 4-aryl-4-oxobut-2-enoates was achieved with FeCl3 as a catalyst under mild conditions. The reaction was highly regioselective and afforded a variety of new 3-substituted indoles in good to excellent yields.