JohnPhos | CAS 224311-51-7 | ≥97%

Technical Specifications

Product Description & Scientific Applications

JohnPhos (2-(di-tert-butylphosphino)biphenyl; (2-biphenyl)di-tert-butylphosphine) is a sterically bulky, electron-rich monodentate dialkylbiaryl phosphine of the Buchwald-type ligand family. A di-tert-butylphosphino group is mounted at the 2-position of a biphenyl scaffold, combining strong σ-donation from the two tert-butyl groups with the steric profile of the biaryl backbone. This bulky, electron-rich architecture is characteristic of dialkylbiaryl phosphine ligands that promote reactive monoligated palladium species in many cross-coupling manifolds. JohnPhos is supplied as a crystalline solid that is convenient to weigh and handle; minimise prolonged air exposure to preserve the trivalent phosphine.

Palladium-catalysed C–N coupling (Buchwald–Hartwig amination)

JohnPhos is used as a supporting ligand in palladium-catalysed amination, forming aromatic C–N bonds from aryl chlorides, bromides or triflates and amine partners. It is especially relevant where a bulky, electron-rich monophosphine is needed to promote oxidative addition and productive C–N bond formation.

Palladium-catalysed C–C coupling

JohnPhos is used in palladium-catalysed C–C bond formation, including Suzuki–Miyaura coupling of aryl chlorides, bromides and triflates, and Stille-type cross-coupling. Reported applications also include arylation of heteroarenes and enolate-derived partners, such as silyl enol ether chemistry, where a bulky electron-rich monophosphine helps tune oxidative addition and reductive elimination.

Gold(I) catalysis

JohnPhos is a prominent ligand in homogeneous gold(I) catalysis. Well-defined complexes such as JohnPhosAuCl and cationic JohnPhos–gold(I) species generated from it are used for alkyne activation and cycloisomerisation chemistry, including aminocyclisation of 1,6-enynes. In selected gold-catalysed alkyne functionalisation reactions, the less encumbered JohnPhos environment can give different activity or selectivity from bulkier biaryl phosphines.

Coordination chemistry

As a strong σ-donor monophosphine, JohnPhos forms well-defined complexes with palladium and gold, and its biphenyl phosphine scaffold is useful for tuning steric and electronic effects across dialkylbiaryl phosphine ligand design.

Handling note

JohnPhos is a tertiary phosphine supplied as a crystalline solid. For demanding catalytic work, store cool and dry, minimise prolonged air exposure, and handle solutions under inert atmosphere where ligand purity is critical.

Shipping Destinations

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