Palladium-catalyzed NHC ligand-controlled regiodivergent allyl-fluoroallyl cross-couplings

Abstract

The palladium-catalyzed cross-coupling of (E)-2-fluoroallyl carbonates and allylboronates is reported. The regioselectivity is susceptive to the steric requirements of the NHC ligand, with small IMes favoring linear fluorinated 1,5-dienes, while IPr^BIDEA featuring sterically-congested character benefits branched products. Control experiments revealed that either 2-fluoroallyl carbonates or gem-F₂CPs could undergo allylation with excellent regioselectivity, yet the former showed somewhat lower branched reactivity.