59th Annual Report on Research 2014

Results from Last Year of Support We focused PRF resources in detail on an exploration of the iron-catalyzed benzylic fluorination of substrates containing aromatic rings and electron-withdrawing groups positioned alpha to one another, thus providing direct access to a-fluorinated adducts. This operationally convenient process can be thought of not only as a contribution to the timely problem of benzylic fluorination, but also as a functional equivalent to a conjugate addition of fluoride, furnishing products in moderate to good yields and in excellent selectivity (Scheme 1).

Scheme 1.

In very fruitful work on difluorination, a dually activated ketene enolate, generated from an acid chloride, the unusual chelating nucleophile (1,8-naphthyridine) and a Lewis acid, reacts to afford a host of α,α-difluorinated products in the presence of a bench top stable fluorinating agent (Selectfluor). The use of this method to synthesize otherwise difficult to make products is highlighted in a publication along with computational and spectroscopic support for the proposed chelate (Scheme 2).

Scheme 2.

These results mark the end of funding for this grant. Although we deviated from the original proposed research, the end results were more important than the originals would have ever been. We are therefore grateful to the ACS-PRF for its support.