Highly Regioselective Difluoroalkylarylation of Butadiene through a Nickel-Catalyzed Tandem Radical Process

A nickel-catalyzed
reaction of 1,3-butadiene with easily accessible
difluoroalkyl bromides and arylboronic acids has been realized, affording
the corresponding 1,4-difluoroalkylarylation products in good yields
with high regioselectivities. The procedure can also be successfully
extended to nonfluorinated alkyl bromides. A radical clock experiment
suggests that a key alkyl radical is involved in the catalysis. The
operational simplicity, excellent functional-group compatibility,
and high efficiency should make this nickel-catalyzed three-component
reaction highly promising for the cost-efficient synthesis of difluoroalkylated
compounds.