In this work, six novelaxiallyunfixed biaryl‐based water‐compatible bifunctionalorganocatalysts were designed and synthesized for the organocatalytic access to a variety of 3‐alkyl‐3‐hydroxy‐2‐oxindole derivatives via aldol reactions in water. Organocatalyzed by 5a, the direct aldol reactions of isatins with enolisable ketones underwent readily in water, furnishing the structurally diverse 3‐al
The synthesis and application of a newly designed C2-symmetric chiral bifunctional triamine family (C2-CBT) is reported. These enantiopure chiral triamine scaffolds can be accessed in multigram amounts from simple amino acids while avoiding chromatographic purification. As a proof of principle, C2-CBT has been studied in the aldol reaction of cyclic ketones with isatins, with the target tertiary alcohols
Ultrasonication-Assisted Synthesis of a <scp>d</scp>-Glucosamine-Based β-CD Inclusion Complex and Its Application as an Aqueous Heterogeneous Organocatalytic System
infrared spectroscopy, nuclearmagneticresonancespectroscopy, ultraviolet–visible spectroscopy, thermogravimetric analysis, scanning electron microscopy, and other spectroscopic techniques. It was observed that the inclusion of a d-glucosamine derivative into the hydrophobic cavity of β-CD increased its surface area and thermal stability. This catalytic system worked well in water for the direct aldol
Optically active 2-azanorbornane-based organocatalysts were designed and synthesized, and the catalytic activity of these catalysts in enantioselective aldol reactions of isatins with ketones was investigated. Among these catalysts, 2-azanorbornylmethanol showed the best catalytic activity to afford the corresponding aldol product in excellent chemical yield (up to 95%) and with moderate stereoselectivity (up to 64% ee, up to syn:anti = 36:64). (C) 2016 Elsevier Ltd. All rights reserved.