Enantioselective Construction of Cyclopenta[b]indole Scaffolds via the Catalytic Asymmetric [3 + 2] Cycloaddition of 2-Indolylmethanols with p-Hydroxystyrenes

J Org Chem. 2017 Oct 6;82(19):10226-10233. doi: 10.1021/acs.joc.7b01731. Epub 2017 Sep 25.

Abstract

The catalytic asymmetric [3 + 2] cycloaddition of 2-indolylmethanols to p-hydroxystyrenes was established in the presence of a chiral phosphoramide, and this reaction provided chiral cyclopenta[b]indole scaffolds in generally high yields and with good enantioselectivities (up to 98% yield, 99:1 er). The control experiments demonstrated that the dual hydrogen-bonding activation mode of the chiral catalyst toward the two substrates played an important role in the reaction. In addition, the large-scale reaction indicated that this catalytic asymmetric [3 + 2] cycloaddition could be scaled up for the synthesis of chiral cyclopenta[b]indole derivatives.

Publication types

  • Research Support, Non-U.S. Gov't