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

New l-prolinol derived chiral liquids in asymmetric organocatalysis.

(S)-(1-Pyrrolidin-2-ylmethyl)quinuclidine-1-ium bromide was synthesized in a six-step reaction process starting from l-proline and spectroscopically and thermally characterized.

N -Aryl glycines reacted with N -substituted maleimides, leading to functionalized tetrahydroquinolines in a radical-mediated Povarov-type reaction carried out under visible light irradiation and using deep eutectic solvents as reaction media under ambient air. The use of various photocatalysts and additives was explored, but the reaction performed best in their absence, via the formation of a photoactive electron donor-acceptor complex. The most effective eutectic solvent could be recovered and reused. The proposed mechanism was supported by different chemical and physical studies, as well as theoretical calculations.