Hypervalent Iodine Catalyst Grants Access to 1,4-Difunctionalized Fluorinated Olefins

Contributors: Benjamin List, Margareta M. Poje

Significance

Gilmour and co-workers report an iodine(I)/iodine(III)-catalyzed 1,4-difluorination of trifluoromethyl-substituted 1,3-dienes. E,Z mixtures of dienes are converted into a single ­(E)-isomer ­in moderate to very good yields. The approach was further developed to enable heterodifunctionalization with a variety of nucleophiles, including ­nitriles, carboxylic acids, alcohols and water.

Comment

The reported method expands the well-established series of catalytic 1,1-, 1,2- and 1,3-difluorination strategies and facilitates access to highly functionalized structures. The regioselectivity (1,4:1,2 from 2:1.1 to >20:1) is dependent on the electronic properties of the aryl substituents, which supports the suggested stepwise mechanism. We look forward to a report on the authors’ efforts toward an enantioselective variant of the method.