An Improved Ring‐Closing Metathesis Approach to Fluorinated and Trifluoromethylated Nitrogen Heterocycles

Abstract

Abstract The synthesis of fluoro‐ and trifluoromethyl‐containing N ‐sulfonylated nitrogen heterocycles is described. A first crucial step is a Mitsunobu functionalization of intermediate sulfonamides using commercially available unsaturated alcohols, which gives efficient access to fluorinated ring‐closing metathesis (RCM) precursors. Key step is an RCM reaction of these precursors leading to the corresponding fluoro‐ and trifluoromethyl‐containing heterocyclic building blocks. Furthermore, aminopalladation of the same sulfonamide intermediates provides access to trifuoromethyl‐containing pyrrole derivatives.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)