Chiral Palladacycle Catalysts Generated on a Single‐Handed Helical Polymer Skeleton for Asymmetric Arylative Ring Opening of 1,4‐Epoxy‐1,4‐dihydronaphthalene

Abstract

Post-polymerization CH activation of poly(quinoxaline-2,3-diyl)-based helically chiral phosphine ligands (PQXphos) with palladium(II) acetate afforded chiral phosphapalladacycles quantitatively. In situ generated palladacycles exhibited enantioselectivities up to 94 % ee in the palladium-catalyzed asymmetric ring-opening arylation of 1,4-epoxy-1,4-dihydronaphthalenes with arylboronic acids.

Crystallization‐Driven Asymmetric Helical Assembly of Conjugated Block Copolymers and the Aggregation Induced White‐light Emission and Circularly Polarized Luminescence

“…[23,24] Encouraged by the helical structures and functions in nature,agreat deal of studies have been conducted on artificial helical materials such as helical polymers and assemblies. [25][26][27] These studies not only explore the structures and functions of their natural counterparts,but also and more importantly,develop new functional materials with applications in, for example,c hiral resolution, [28] asymmetric catalysis, [29,30] chiral switch, [31,32] and circularly polarized luminescence (CPL). [33,34] Among them, CPL has lately attracted increasing attentions on account of their potentials in chemical sensors,biological probes,and three-dimensional displays.…”

Catalysts Supported by Homochiral Molecular Helices: A New Concept to Implement Asymmetric Amplification in Catalytic Science

“…and arylative ring-opening of 1,4-epoxy-1,4dihydronaphthalene (up to 94% e.e.). [38] In the silaborative cleavage of meso-methylenecyclopropanes [39] (up to 97% e.e. ), these PQXs ligands provided comparable or higher selectivities than known discrete chiral ligands.…”

Deracemisations under kinetic and thermodynamic control

“…Moreover, the SaS effect was operative in the polymers; only small amounts of chiral monomer were required to bias the polymer's helical sense preference. [100][101][102][103] Several asymmetric reaction (hydrosilylations, Suzuki-Miyaura cross-couplings) were compatible with these helical polymer systems, producing a variety of products in very high ee. 104 Intriguingly, not only solvent polarity but also solvent shape could alter the helical sense preference.…”