Enantioselective Catalytic Aldol Reactions in the Presence of Knoevenagel Nucleophiles: A Chemoselective Switch Optimized in Deep Eutectic Solvents Using Mechanochemistry

Molecules, Journal Year: 2023, Volume and Issue: 29(1), P. 4 - 4

Published: Dec. 19, 2023

In the presence of different nucleophilic Knoevenagel competitors, cyclic and acyclic ketones have been shown to undergo highly chemoselective aldol reactions with aldehydes. doing so, substrate breadth for this emerging methodology has significantly broadened. The method is also no longer beholden proline-based catalyst templates, e.g., commercially available O-t-Bu-L-threonine advantageous ketones. key insight was exploit water-based mediums under conventional (in-water) non-conventional (deep eutectic solvents) conditions. With few exceptions, high aldol-to-Knoevenagel chemoselectivity (>10:1) good product profiles (yield, dr, ee) were observed, but only in DESs conjunction ball milling did short reaction times occur.

Language: Английский

Construction of three contiguous stereocenters through amine-catalyzed asymmetric aldol reactions

Chemical Communications, Journal Year: 2023, Volume and Issue: 59(54), P. 8424 - 8427

Published: Jan. 1, 2023

Three contiguous stereocenters were constructed by an amino acid-catalyzed asymmetric aldol reaction of α-siloxyketones with racemizable α-haloaldehydes via dynamic kinetic resolution. One-pot catalytic synthesis the highly functionalized products could also be accomplished α-bromination simple aldehydes and subsequent reaction.

Language: Английский