We report here a palladium-catalyzed
enantioselective synthesis
of indole-based atropisomers via an intramolecular dynamic kinetic
C–H cyclization. The TADDOL-derived phosphoramidite ligand
proves to be most efficient in this directing-group-free transformation,
delivering products with up to 96:4 er. The thermal stability of the
axial chirality of the atropisomers has also been investigated.
A Cu-catalyzed asymmetric thiolative ring opening reaction of five-membered diaryliodonium salts and potassium thioates for the synthesis of atropisomeric 2'-iodo-[1,1'-biphenyl]-2-yl thioates was realized. The optimal catalytic system, Cu(CHCN)PF/(Ph)-bis(oxazoline), showed the best performance with respect to both yields and stereocontrol. Finally, the utility of these products was briefly demonstrated by the synthesis of an axially chiral P,S-ligand.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.