Asymmetric Michael addition reactions catalyzed by a novel upper-rim functionalized calix[4]squaramide organocatalyst
作者:Ke Yang、Zhiyan Ma、Hong-Xiao Tong、Xiao-Qiang Sun、Xiao-Yu Hu、Zheng-Yi Li
DOI:10.1016/j.cclet.2020.02.057
日期:2020.12
Abstract A novel upper-rim functionalizedcalix[4]squaramide organocatalyst bearing bis-squaramide and cyclohexanediamine scaffolds was designed and prepared to catalyse a serial of asymmetric Michael addition of 1,3-dicarbonyl compounds to α,β-unsaturated carbonyl compounds in high yields (up to 99 %) and good to excellent enantiomeric excesses (up to 99% ee). The comparative experiments indicated
Ferrocene Analogues of Hydrogen-Bond-Donor Catalysts: An Investigative Study on Asymmetric Michael Addition of 1,3-Dicarbonyl Compounds to Nitroalkenes
作者:Rajiv Trivedi、Kadiyala Rao、M. Kantam
DOI:10.1055/s-0034-1379491
日期:——
moieties. A stepwise sequential route was used to assemble the various components of these ferrocene derivatives. The resulting bifunctional catalysts were used successfully in asymmetric Michael additions of 1,3-dicarbonylcompounds to β-nitrostyrenes. The corresponding products were obtained in high yields and in good to excellent enantioselectivities and diastereoselectivities under mild conditions by
Novel Chiral Bifunctional L-Thiazoline-Thiourea Derivatives: Design and Application in EnantioselectiveMichael Reactions
作者:Qi Lai、Yang Li、Zhiyong Gong、Qingwen Liu、Chiyu Wei、Zhiguang Song
DOI:10.1002/chir.22540
日期:2015.12
Several novelchiralbifunctional L‐thiazoline‐thioureaderivatives were easily synthesized from commercially available L‐cysteine in high yield. These catalysts were subsequently applied to the enantioselective Michael addition of acetylacetone to β‐nitrostyrenes. The products with S configuration were obtained in 98% enantiomeric excess (ee) when the L‐thiazoline‐thioureaderivatives were used. A
The chiral squaramide derivatives as hydrogen bonding catalyst for the Michael addition reactions of 1,3-dicarbonyl compounds to nitroolefins under solvent-free conditions was developed using a planetary ball mill. High yields, high enantioselectivities and shorter reaction times were achieved with lowcatalystloading.
Doubly stereocontrolled asymmetric Michael addition of acetylacetone to nitroolefins promoted by an isosteviol-derived bifunctional thiourea
作者:Zhi-wei Ma、Yu-xia Liu、Li-juan Huo、Xiang Gao、Jing-chao Tao
DOI:10.1016/j.tetasy.2012.03.020
日期:2012.4
A novel class of chiral bifunctionalthioureas bearing a chiral lipophilic beyerane scaffold and a tertiary amino group was designed and prepared. The thioureas were proven to be effective for catalyzing the doubly stereocontrolled asymmetricMichaeladdition between acetylacetone and nitroolefins. The corresponding adducts were obtained in high yields (up to 95%) and with good to excellent enantioselectivities