meta-Selective olefination of fluoroarenes with alkynes using CO2as a traceless directing group

Abstract

Over the last few decades C-H olefination has received significant interest, due to the importance and usefulness of aryl olefins both as synthetic targets and intermediates. While a wide range ofortho-olefination protocols have been developed, only a small number ofmeta-olefinations are currently available. Importantly, the most common approach tometa-olefination, using a largemeta-directing template, is not suitable for substrates such as fluorobenzenes, which cannot be derivatised. We report that themeta-selective olefination of fluoroarenes can be achievedviathe use of CO2as a traceless directing group, which can be easily installed and removed in a one-pot process. Furthermore, this approach avoids the use of stoichiometric Ag(i)-salts, commonly used in C-H olefinations, and affords completemeta- overortho/para-regioselectivity.