Bis-indole chiral architectures for asymmetric catalysis

Abstract

Chiral scaffolds are essential to the advancement of asymmetric synthesis, yet the development of privileged motifs that more effectively communicate asymmetry constitutes a grand challenge for chemists. Here we describe a method using a confined chiral Brønsted acid catalyst to combine two inexpensive and widely available materials—indole and acetone—into a class of C₂-symmetric, spirocyclic compounds called SPINDOLE. SPINDOLEs extend the versatility of established frameworks by offering greater flexibility and ease of synthesis. The resulting chiral compounds can be readily modified to create diverse structures that excel in promoting highly selective reactions such as hydrogenation, allylic alkylation, hydroboration, and Michael addition. This work introduces a powerful strategy for advancing asymmetric catalysis, enabling the creation of versatile chiral frameworks with broad synthetic potential.