Pd ^II ‐Catalyzed Monoselective <i>ortho</i> Halogenation of CH Bonds Assisted by Counter Cations: A Complementary Method to Directed <i>ortho</i> Lithiation

Abstract

When the counterion counts: The yield and selectivity of the title transformation of benzoic acid derivatives were improved greatly by using tetraalkyl ammonium salts as additives (see scheme; monoselectivity: 5:1–18:1). These effects are attributed to the influence of counter cations. The halogenated products are versatile intermediates for the construction of substituted aromatic compounds. DMF=N,N-dimethylformamide. Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2002/2008/z705613_s.pdf or from the author. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.