# Enantioselective Pictet–Spengler-Type Reaction via a Helically Chiral Anion as an Access to 4,5-Dihydropyrrolo[1,2‑a]quinoxaline Scaffolds

## TL;DR

A new enantioselective chemical reaction is developed using a chiral catalyst to create a new class of chiral compounds with improved stability.

## Contribution

The use of a helically chiral cyclopentadiene catalyst enables a novel enantioselective Pictet–Spengler-type reaction.

## Key findings

- The method produces chiral 4,5-dihydropyrrolo[1,2-a]quinoxalines with resistance to aromatization.
- The reaction is conducted under mild conditions with broad substrate compatibility.
- The protocol shows significant synthetic versatility for creating new chiral compounds.

## Abstract

We report an enantioselective Pictet–Spengler-type
reaction
enabled by a cost-effective and readily available helically chiral
cyclopentadiene (PCCP) catalyst. This methodology, conducted under
mild reaction conditions, facilitates the synthesis of a novel class
of chiral 4,5-dihydropyrrolo­[1,2-a]­quinoxalines (DHPQs)
characterized by enhanced resistance to aromatization due to intramolecular
hydrogen bonding. Additionally, the protocol exhibits broad substrate
compatibility and demonstrates significant synthetic versatility.