手性铜( II )络合物催化丙二酸酯对β,γ-不饱和-α-酮酯的对映选择性迈克尔加成反应,实现了高产率(高达96%)和高ee(高达92%) 。手性配体同时利用了联萘基和脯氨酸部分,并且可以容忍具有不同电子和空间特征的取代基。反应可以在温和的条件下进行,并且可以在不损失产率和对映选择性的情况下实现克级反应。
Enantioselective Michael Addition of 2-Hydroxy-1,4-naphthoquinone to β,γ-Unsaturated α-Keto Esters Catalyzed by Binaphthyl-Modified Squaramide
作者:Ji Hyun Lee、Dae Young Kim
DOI:10.5012/bkcs.2013.34.6.1619
日期:2013.6.20
catalyst loading and long reactiontime for high enantioselectivity. Accordingly, the develop-ment of alternative catalysts for the enantioselective Michaeladdition of 2-hydroxy-1,4-naphthoquinones to β,γ-unsatu-rated α-keto esters is highly desirable.As part of our research program related to the develop-ment of synthetic methods for the enantioselective construc-tion of stereogenic carbon centers,
Highly Enantioselective Friedel-Crafts Reaction of 4,7-Dihydroindoles with β,γ-Unsaturated α-Keto Esters by Chiral Brønsted Acids
作者:Mi Zeng、Qiang Kang、Qing-Li He、Shu-Li You
DOI:10.1002/adsc.200800523
日期:2008.10.6
A highly efficient Friedel–Craftsreaction of 4,7-dihydroindoles with β,γ-unsaturatedα-ketoesters by a chiral N-triflyl phosphoramide was realized, affording the 2-substituted 4,7-dihydroindoles with up to 98% ee for a wide range of substrates. The Friedel–Crafts alkylation together with a subsequent oxidation of the product with p-benzoquinone led to a 2-alkylated indole derivative in 98% ee.
Highly stereoselective construction of tetrahydroquinolines via cascade aza-Michael-Michael reaction: Formal [4+2] cycloaddition of β,γ-unsaturated α-ketoesters with 2-aminochalcones
作者:Cong Duan、Yongqi Yao、Ling Ye、Zhichuan Shi、Zhigang Zhao、Xuefeng Li
DOI:10.1016/j.tet.2018.10.053
日期:2018.12
An efficient cascade aza-Michael-Michael sequence for the preparation of tetrahydroquinolines has been established. Three contiguous stereogenic centers are created with high levels of enantioselectivities (79–99% ee) and exclusive diastereoselectivities in the presence of a bifunctional squaramide. This approach is compatible with a broad range of β,γ-unsaturated α-ketoesters and 2-aminochalcones
An organocatalyticenantioselectiveMichaeladdition of 2-hydroxy-1,4-naphthoquinone to β,γ-unsaturatedα-oxoesters has been developed. The process was promoted by bifunctional chiral amine derived squaramides according to a hydrogen-bonding mediated activation mechanism and afforded the chiral adducts in high yields (up to 88 %) and excellent enantioselectivity (up to 98 % ee) under mild conditions
Asymmetric Michael/hemiketalization of 5-hydroxy-2-methyl-4H-pyran-4-one to β,γ-unsaturated α-ketoesters catalyzed by a bifunctional rosin–indane amine thiourea catalyst
作者:B. V. Subba Reddy、Manisha Swain、S. Madhusudana Reddy、J. S. Yadav、B. Sridhar
DOI:10.1039/c4ra06938b
日期:——
A highly efficient enantioselective Michael-hemiketalization cascade process is reported using a chiral bifunctional rosin–indane amine thiourea catalyst.