Enantioselective synthesis of N–C axially chiral indoles through chiral palladium-catalyzed 5-endo-hydroaminocyclization

Advances in Stereoconvergent Catalysis from 2005 to 2015: Transition-Metal-Mediated Stereoablative Reactions, Dynamic Kinetic Resolutions, and Dynamic Kinetic Asymmetric Transformations

“…218,219 The authors recognized that the (2- t -butylphenyl)indoles have a high rotational barrier and can be accessed via an atroposelective, intramolecular cyclization starting from ethynylaryl anilines 232 . Of the numerous chiral ligands screened, ( R )-SEGPHOS 168 (Figure 13) was found to affect the cyclization with highest enantioselectivity.…”

Conversion of two stereocenters to one or two chiral axes: atroposelective synthesis of 2,3-diarylbenzoindoles

“…Indole-based biaryl atropisomers including N -aryl, C(2)-aryl, and C(3)-aryl axial chirality are potential ligands and found in some natural products 17. In 2010, Kitagawa reported Pd-catalyzed hydroaminocyclization to construct indole N -aryl axial chirality 18. Later, Kamikawa, Takahashi and Ogasawara reported an enantioselective desymmetrising ring-closing metathesis strategy to prepare axially chiral indole N -aryl compounds 19.…”

JoyaPhos: An Atropisomeric Teraryl Monophosphine Ligand

“…Atropisomers with rotationally restricted C−N bonds are potential targets or intermediates for the synthesis of biologically active molecules, such as compounds of medicinal interest or pest‐control agents . Synthetic methodologies to control C−N stereogenic axes employing cross‐coupling strategies are therefore currently investigated utilizing several notably elegant approaches . While the inherent steric bulk of the JoyaPhos ligand would favor the formation of catalytically active monoligated LPd(0) species, the naphthyl backbone and the side anthracenyl group likely prevent cyclometalative pathways that often result in a decreased catalytic activity .…”