Asymmetric Friedel-Crafts alkylation of indoles with 2-nitro-3-arylacrylates catalyzed by a metal-templated hydrogen bonding catalyst

摘要

An asymmetric Friedel-Crafts alkylation of indoles with 2-nitro-3-arylacrylates catalyzed by a metal-templated hydrogen bonding catalyst has been established. The asymmetric induction relies on chirality transfer solely from the octahedral metal stereocenter via three weak hydrogen bonds. All the products are provided with good to excellent enantioselectivities while modest diastereoselectivities, which can be converted into a variety of valuable indole-containing chiral building blocks including tryptophan derivatives. (C) 2015 Elsevier Ltd. All rights reserved.