Resin-immobilized pyrrolidine-based chiral organocatalysts for asymmetric Michael additions of ketones and aldehydes to nitroolefins

Abstract

Based on the electrostatic adsorption between acidic resins and organocatalysts, a series of resin-supported chiral organocatalysts were designed and synthesized.

Chiral catalysts immobilized on achiral polymers: effect of the polymer support on the performance of the catalyst

“…Leaching is also a problem associated with chiral organocatalysts based on amines or polyamines immobilized on acidic resins through protonation and electrostatic interactions and some strategies have been devised for its minimization. 291,292…”

Recent Advances in Asymmetric Organocatalyzed Conjugate Additions to Nitroalkenes

“…Some efforts destined to recycle pyrrolidine-based catalyst active in the Michael addition of cyclohexanone to trans -β-nitrostyrene have been carried out. Thus, resin-immobilized pyrrolidine catalyst 60 [ 88 ] has been used, under solvent free conditions, in this transformation for 16 successive runs without significant loss of enantioselectivity ( Scheme 12 ). The catalytic efficiency was also demonstrated by using other nitroolefins as electrophiles, leading to similar results in terms of yields and stereoselectivities.…”

Silica gel-immobilized multidisciplinary materials applicable in stereoselective organocatalysis and HPLC separation

“…The current approach to address this problem involves immobilization of the catalyst to a solid support. 28 Several types of solid matrices, such as polystyrene, [29][30][31][32][33][34][35] metal nanoparticles, 36,37 metalorganic frameworks, 38 ion-modied resins for non-covalent binding, [39][40][41] or mesoporous silica [42][43][44][45] have been introduced as solid supports for various types of organocatalysts.…”