Synthesis of planar chiral [2.2]paracyclophane-based amino thioureas and their application in asymmetric aldol reactions of ketones with isatins
作者:Yu Lu、Yudao Ma、Shaobo Yang、Manyuan Ma、Hongju Chu、Chun Song
DOI:10.1016/j.tetasy.2013.07.023
日期:2013.9
were used as bifunctionalcatalysts for organocatalytic enantioselective aldolreactions between ketones and isatins, affording the desired adducts containing a chiral tertiary alcohol in high yields (up to 92% yield) and with good enantioselectivity (up to 88% ee). This is a successful example of employing planar chiral [2.2]paracyclophane-based amino thioureas in asymmetricaldolreactions.
Urea derivative catalyzed enantioselective aldol reaction of isatins with ketones
作者:Li Ming Wang、Mei Jun Zhao、Zhe Chen、Hong Wen Mu、Ying Jin
DOI:10.1002/chir.22977
日期:2018.8
Urea derivative has been used to catalyze the asymmetricaldolreaction of isatins with ketones. The resulting 3‐alkyl‐3‐hydroxy‐indolin‐2‐ones products were obtained in good yields (70%‐94%) with high enantioselectivities (up to 87%ee).
Quinidine Thiourea-Catalyzed Aldol Reaction of Unactivated Ketones: Highly Enantioselective Synthesis of 3-Alkyl-3-hydroxyindolin-2-ones
作者:Qunsheng Guo、Mayur Bhanushali、Cong-Gui Zhao
DOI:10.1002/anie.201004161
日期:2010.12.3
New catalysis mechanism! The asymmetricaldolreaction of unactivated ketones and activated carbonyl compounds is realized with a quinidine‐derived thiourea catalyst (see scheme), and involves an enolate mechanism instead of the widely used enamine mechanism. With isatins as the substrate, the reaction can be applied to the enantioselective synthesis of biologically active 3‐hydroxyindolin‐2‐ones.
Enantioselective aldol reactions of isatins with acetone using phthalimido-prolinamide organocatalyst 1 are described. The protocol was effective under solvent free and additive free reaction conditions with 20 mol % of 1 leading to the desired aldol products in good yields and with good enantioselectivities. (C) 2015 Elsevier Ltd. All rights reserved.