The synthesis of dihydropyrroles, pyrroles, and indoles through
[3-atom + 2-atom] combination of
ethyl or aryl tosylamide anions with phenyl(propynyl)iodonium
triflate, and the base-mediated
intramolecular bicyclization of alkynyliodonium-bearing tosylamide or
tosylimide substrates to
furnish bicyclic and tricyclic tosylenamide (-enimide) products, is
described. A detailed discussion
of the scope, limitations, byproduct formation, and the basis for
observed diastereoselectivity is
presented.
The Noyori-Ikariya catalysts, Ru-TsDPEN 1 or 2, in combination with HCOOH/Hunig's base (5:2) have been successfully utilized for catalytic asymmetric transfer hydrogenation of alpha-ketopantolactam, and optically enriched N-substituted pantolactam was prepared (S/C = 500, up to 95% ee and 99% conversion in HCOOH/Hunig's base condition). More than 2 kg of this key intermediate 9 has been synthesized efficiently with excellent chemical yield and chiral purity.
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.