Iridium‐Catalyzed Enantioselective Intramolecular Hydroarylation of Allenes: Formal Synthesis of (+)‐Rhazinilam
Abstract
Abstract We report a versatile, highly enantioselective intramolecular hydroarylation of allenyl‐tethered pyrroles and indoles. The reaction, promoted by an iridium(I)/bisphosphine chiral catalyst, provides a direct access heteropolycyclic systems bearing either tertiary or quaternary carbon stereocenters and a synthetically appealing alkenyl pendant. The method allows a highly efficient assembly of five‐, six‐ and even seven‐membered fused indole and pyrrole products, providing enantiomeric excesses of up to 99%. DFT computational studies align nicely with the experimental results and allow to rationalize the key factors that control both regio‐ and stereoselectivity of the process. Finally, the synthetic potential of the method was exemplified with a very short, highly enantioselective formal synthesis of (+)‐Rhazinilam.
Article Details
Authors (5)
Andrés Arribas
Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS) and Departamento de Química Orgánica Universidade de Santiago de Compostela
Alejandro Rey
Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS) and Departamento de Química Orgánica Universidade de Santiago de Compostela Santiago de Compostela 15782 Spain
Martín Calvelo
Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS) and Departamento de Química Orgánica Universidade de Santiago de Compostela
José L. Mascareñas
Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS) and Departamento de Química Orgánica Universidade de Santiago de Compostela
Fernando López
Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS) and Departamento de Química Orgánica Universidade de Santiago de Compostela