Organocatalytic Asymmetric 3‐Allenylation of Indoles via Remote Stereocontrolled 1,10‐Additions of Alkynyl Indole Imine Methides

Abstract A chiral phosphoric acids catalyzed regio‐ and enantioselective 1,10‐conjugate addition of 2‐arylindoles to alkynyl indole imine methides formed in situ from α‐(6‐indolyl)propargylic alcohols has been developed. With the established system, organocatalytic asymmetric 3‐allenylation of indoles was realized, affording a broad scope of axially chiral tetrasubstituted allenes bearing two indole motifs in high yields with stereoselectivities. Importantly, the organocatalytic remote stereocontrolled strategy disclosed the asymmetric 3‐allenylation of indoles via 1,10‐conjugate addition for the first time.