Dual Cu/Ir Catalyzed Asymmetric Allylation and Pictet-Spengler Cyclization: Stereodivergent Access to Chiral Indole Fused 9-Azabicyclo[4.2.1]nonanes†

Abstract

Nitrogen-containing bridged-heterocycles and indoles are key subunits of many natural products and pharmacologically active molecules. We herein present a bimetallic Cu/Ir catalyzed asymmetric allylation of ketimine esters and (E)-4-indolyl allyl carbonates followed by acid-promoted Pictet-Spengler cyclization sequences, enabling stereodivergent synthesis of chiral indole fused 9-azabicyclo[4.2.1]nonanes containing an eight-membered ring with one tertiary and two quaternary stereogenic centers. This one-pot sequential protocol features step economy, good substrate tolerance, and excellent stereoselective control.