Atroposelective Construction of Axially Chiral <scp>Alkene‐Indole</scp> Scaffolds <i>via</i> Catalytic Enantioselective Addition Reaction of <scp>3‐Alkynyl</scp>‐2‐indolylmethanols^†

Abstract

Main observation and conclusion Atroposelective construction of axially chiral alkene‐heteroaryl scaffolds is highly desired but challenging. In this work, we established an atroposelective construction of axially chiral alkene‐indole scaffolds via the strategy of catalytic enantioselective addition reaction of 3‐alkynyl‐2‐indolylmethanols with bulky nucleophiles. In this strategy, α‐amido sulfones were used as competent nucleophiles and chiral phosphoric acid (CPA) acted as suitable chiral catalyst for this addition reaction. By this strategy, a new class of axially chiral acyclic alkene‐indoles was synthesized in overall high yields (up to 86%), excellent ( E / Z )‐selectivity (all &gt; 95 : 5) and good enantioselectivities (up to 92 : 8 er). This reaction represents the first catalytic enantioselective construction of axially chiral alkene‐indole frameworks, which will add a new member to the family of atropoisomeric heterocycles, especially the family of axially chiral indole compounds.