Stereoselective (3 + 3)-Cycloannulation of Carbonyl Ylides and (<i>Z</i>)-3-Benzylidene-3<i>H</i>-indoles Enabled by Cooperative Rh/Chiral Phosphoric Acid Catalysis
Jyotish Barman, Spoorthi Ananda, Subhas Chandra Pan
Abstract
A diastereo- and enantioselective (3 + 3)-cycloannulation of in situ generated carbonyl ylides and ( Z )-3-benzylidene-3 H -indoles enabled by cooperative Rh/chiral phosphoric acid catalysis is reported. This study is the first to describe an enantioselective synthesis of cyclohepta[ b ]indole with an oxa-bridged motif. The scope of the reaction is broad, and the oxa-bridged cyclohepta[ b ]indole products were obtained in moderate to good yields and with excellent diastereoselectivities and good to high enantioselectivities.
Topics & Concepts
ChemistryStereoselectivityCatalysisPhosphoric acidStereochemistryOrganic chemistryMedicinal chemistryCyclopropane Reaction MechanismsCatalytic C–H Functionalization MethodsAsymmetric Hydrogenation and Catalysis