Synthesis of Chiral Polyamides Containing an (R,R)‐1,2‐Diphenylethylenediamine Monosulfonamide Structure and Their Application to Asymmetric Transfer Hydrogenation Catalysis

Abstract

A chiral main‐chain polyamide containing an (R,R)‐1,2‐diphenylethylenediamine monotoluenesulfonamide (TsDPEN) repeating unit was prepared. Polycondensation of dicarboxylic acid dichloride with the chiral bisaniline of N‐tert‐butoxycarbonyl‐protected TsDPEN was successful and afforded a chiral polyamide with a TsDPEN repeating unit as the chiral ligand structure. Treatment of the main‐chain polymer chiral ligand with transition‐metal complexes, such as [IrCl2Cp*]2 (Cp*=η5‐pentamethylcyclopentadienyl), [RhCl2Cp*]2, and [RuCl2(p‐cymene)]2, afforded polymer chiral metal complexes. Asymmetric transfer hydrogenation of a cyclic sulfonamide was efficiently catalyzed by the chiral TsDPEN polymer–metal complex to give an optically active cyclic sulfonylamine with quantitative conversion and high enantioselectivity. The polymer catalyst was easily recovered from the reaction mixture and reused several times without any loss in catalytic activity or enantioselectivity.

Preparation and Chiral Applications of Optically Active Polyamides

“…The as-synthesized polymer was subsequently used as polymer ligand to form polymer chiral metal complexes with Iridium, Rhodium and Ruthenium complex. [48] The resulting polymeric catalysts displayed catalytic activity in the asymmetric transfer hydrogenation of cyclic sulfonimine and acetophenone, and high enantioselectivities observed. These polymeric catalysts were simply separated from the reaction medium and reused several times without any loss in catalytic activity and enantioselectivity.…”

“…Itsuno et al first prepared chiral polyamides by polycondensation of dicarboxylic acid dichlorides with the chiral bisaniline of N-Bocprotected (R, R)-1,2-diphenylethylenediamine monotoluenesulfonamide (TsDPEN). [48] Then, polymer-based chiral metal complexes were obtained by treating the main-chain polymer chiral ligand with transition metal complexes. Finally, the as-acquired chiral polyamides containing TsDPEN repeat units were applied as polymer catalysts for asymmetric transfer hydrogenation of cyclic sulfonimines.…”

Supported Noyori-Ikariya catalysts for asymmetric transfer hydrogenations and related tandem reactions

“…In 2017, Itsuno and Takahashi prepared a chiral main-chain polyamide containing a (R,R)-1,2-(TsDPEN) ligand using a polycondensation method (Scheme 29) [86]. The resulting polymer chiral ligand was combined with [IrCl2Cp*]2 and applied to the ATH of acetophenone and a cyclic sulfonimine to lead to the phenylethanol and sulfonylamine products in high yields and enantioselectivities.…”

Polyamide 1010/Polythioamide Blend Reinforced with Graphene Nanoplatelet for Automotive Part Application

“…1). The mixture was precipitated in water and filtered to obtain the polyamide [21]. FTIR (cm First step was to dissolve 10 g PA1010 in 100 mL NMP.…”