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
Highly Enantioselective Michael Addition of Cyclic Diketones to β,γ-Unsaturated α-Keto Esters Catalyzed by Squaramide Organocatalyst
作者:Zhi-Wei Ma、Chuan-Chuan Wang、Quan-Jian Lv、Xiao-Pei Chen、Ai-Qin Li、Jing-Chao Tao
DOI:10.1055/s-0040-1719863
日期:2022.4
developed and applied to the asymmetric Michaeladdition of cyclic diketones to β,γ-unsaturated α-keto esters. The catalyst system performed well with a low catalyst loading of 1 mol% under mild reaction conditions. A series of synthetically and pharmaceutically useful chiral bicyclic compounds were obtained in high yields (up to 97%) with excellent enantioselectivities (up to 99 % ee). Furthermore, this
Catalytic asymmetric carbon–carbon bond forming reactions catalyzed by tetrahydroisoquinoline (TIQ) N,N′-dioxide ligands
作者:Zamani E.D. Cele、Sphelele C. Sosibo、Pher G. Andersson、Hendrik G. Kruger、Glenn E.M. Maguire、Thavendran Govender
DOI:10.1016/j.tetasy.2013.01.004
日期:2013.2
The use of TIQ-N,N′-dioxide ligands in asymmetric C–C bond forming reactions is described. In the Michael addition of cyclohexane-1,3-dione and malonates to β,γ-unsaturated α-ketoesters, excellent yields (up to 93%) and moderate to good enantioselectivities (70–89% ee) were obtained. The catalytic hetero-ene reaction of 2-methoxypropene with phenylglyoxal gave the ene product in excellent yield (95%)
Highly Enantioselective Michael Addition of Cyclic 1,3-Dicarbonyl Compounds to β,γ-Unsaturated α-Keto Esters
作者:Xing-Kuan Chen、Chang-Wu Zheng、Sheng-Li Zhao、Zhuo Chai、Ying-Quan Yang、Gang Zhao、Wei-Guo Cao
DOI:10.1002/adsc.201000045
日期:——
A highlyenantioselectiveMichaeladdition of cyclic 1,3‐dicarbonyl compounds to β,γ‐unsaturated α‐keto esters catalyzed by amino acid‐derived thiourea‐tertiary‐amine catalysts is presented. Using 5 mol% of a novel tyrosine‐derived thiourea catalyst, a series of chiral coumarin derivatives were obtained in excellent yields (up to 99%) and with up to 96% ee under very mild conditions within a short