# Design of Phosphine-Heteroarenesulfonamide Ligands as Dinuclear Silver Catalysts for Enantioselective Construction of α,β-Diamino Acids

## TL;DR

Scientists created a new silver catalyst that efficiently builds complex chiral molecules with high precision.

## Contribution

A novel dinuclear silver catalyst was developed for enantioselective synthesis of α,β-diamino acids.

## Key findings

- A phosphine–heteroarenesulfonamide ligand acts as a chiral dinuclear silver catalyst.
- The catalyst enables a highly enantioselective Mannich-type reaction with excellent yields.
- Mechanistic studies reveal a bimetallic transition-state architecture controlling stereochemistry.

## Abstract

We designed and developed
a phosphine–heteroarenesulfonamide
ligand and found that it functions as a chiral dinuclear silver catalyst
capable of cooperatively activating both nucleophiles and electrophiles.
As a result, a highly enantioselective Mannich-type reaction between
glycinate Schiff bases and acyclic ketiminoesters, unattainable by
mononuclear catalytic systems, was achieved, affording α,β-diamino
acid derivatives bearing tetrasubstituted chiral carbon centers in
excellent yields and enantioselectivities. The resulting α,β-diamino
acid derivatives were readily transformed into optically active 2-imidazolidinone
and a dipeptide. Comprehensive mechanistic studies combining global
reaction route mapping (GRRM), artificial force-induced reaction (AFIR),
and density functional theory calculations revealed a cooperative
bimetallic transition-state architecture responsible for the observed
stereocontrol. These findings establish a new design principle for
asymmetric catalysis based on homodinuclear activation and highlight
the potential of dinuclear silver catalysis for the construction of
complex chiral molecules.