Cyclization of 4-Phenoxy-2-coumarins and 2-Pyrones via a Double C-H Activation

Org Lett. 2016 Jun 3;18(11):2540-3. doi: 10.1021/acs.orglett.6b00751. Epub 2016 May 19.

Abstract

Aryl-heteroaryl coupling via double C-H activation is a powerful transformation that avoids the installation of activating groups. A double C-H activation of privileged biological scaffolds, 2-coumarins and 2-pyrones, is reported. Despite the rich chemistry of these molecular frameworks, the yields are very good. Excellent regioselectivity was achieved on the pyrones. This methodology was applied to the synthesis of flemichapparin C in three steps. Isotope effect experiments were carried out, and a mechanism is proposed.

Publication types

  • Research Support, Non-U.S. Gov't