Three-Component Asymmetric Polymerization toward Chiral Polymer

Abstract

Chiral-polymers with metal-coordination ability show great potential for mediating asymmetric reactions. However, the synthesis of structurally diverse chiral polymers remains a great challenge, especially doing so efficiently. Herein, four types of Cu-catalyzed multicomponent asymmetric polymerizations were developed using a flexible combination of OBoc-alkyne, amine and azide to facilely afford 30 chiral poly-triazolyl-methanamines with the desired molecular weights (Mn up to 46, 700 g/mol) and well-defined chiral structures. As excellent ligands for coppers, such poly-triazolyl-methanamines exhibit unique catalytic performance: (1) Amphiphilic poly-triazolyl-methanamines prepared from water-soluble azides can self-assemble into nanoparticles in water, exhibiting excellent catalytic efficiency for aqueous click reaction at a low Cu loading of 10 ppm. (2) Poly-triazolyl-methanamines obtained from aromatic amines possessed the capability to sustainably stabilize cuprous upon exposure to water and air for up to 42 days. (3) Chiral poly-triazolyl-methanamines also outperformed commercially available chiral ligands, such as Py-box, in mediating the asymmetric propargylic substitution reaction.