Asymmetric Synthesis of Fused Polycyclic Indazoles through Aminocatalyzed Aza-Michael Addition/Intramolecular Cyclization

J Org Chem. 2016 Aug 5;81(15):6855-61. doi: 10.1021/acs.joc.6b01201. Epub 2016 Jul 13.

Abstract

The first example of an asymmetric aminocatalyzed aza-Michael addition of 1H-indazole derivatives to α,β-unsaturated aldehydes is described. The iminium/enamine cascade process lies at the heart of our strategy, leading to enantioenriched fused polycyclic indazole architectures. Variations on both the α,β-unsaturated aldehydes and the indazole-7-carbaldehyde heterocycles were studied in order to broaden the scope of the transformation in synthetically interesting directions. The fused polycyclic indazoles exhibit fluorescence properties and can undergo synthetic transformations.

Publication types

  • Research Support, Non-U.S. Gov't