-Selective olefination of fluoroarenes with alkynes using CO as a traceless directing group.

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 of -olefination protocols have been developed, only a small number of -olefinations are currently available. Importantly, the most common approach to -olefination, using a large -directing template, is not suitable for substrates such as fluorobenzenes, which cannot be derivatised. We report that the -selective olefination of fluoroarenes can be achieved the use of CO as 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 complete - over /-regioselectivity.