The development of cage phosphine 'DalPhos' ligands to enable nickel-catalyzed cross-couplings of (hetero)aryl electrophiles.

Nickel-catalyzed cross-couplings of (hetero)aryl electrophiles with a diversity of nucleophiles (nitrogen, oxygen, carbon, and others) have evolved into competitive alternatives to well-established palladium- and copper-based protocols for the synthesis of (hetero)aryl products, including (hetero)anilines and (hetero)aryl ethers. A survey of the literature reveals that the use of cage phosphine (CgP) 'DalPhos' (DALhousie PHOSphine) bisphosphine-type ligands operating under thermal conditions currently offers the most broad substrate scope in nickel-catalyzed cross-couplings of this type, especially involving (hetero)aryl chlorides and phenol-derived electrophiles. The development and application of these DalPhos ligands is described in a ligand-specific manner that is intended to serve as a guide for the synthetic chemistry end-user.
Competing Interests: The authors declare the following competing financial interests: Dalhousie University has filed patents on the DalPhos ancillary ligands and derived nickel pre-catalysts used in this work, from which royalty payments may be derived.
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