93260-12-9Relevant articles and documents
The catalytic asymmetric Fischer indolization
Mueller, Steffen,Webber, Matthew J.,List, Benjamin
, p. 18534 - 18537 (2012/01/31)
The first catalytic asymmetric Fischer indolization is reported. In the presence of a 5 mol % loading of a novel spirocyclic chiral phosphoric acid, 4-substituted cyclohexanone-derived phenylhydrazones undergo a highly enantioselective indolization. Efficient catalyst turnover was achieved by the addition of a weakly acidic cation exchange resin, which removes the generated ammonia. The reaction can be conducted under mild conditions and gives various 3-substituted tetrahydrocarbazoles in generally high yields.
