Dppf (1,1'-Bis(diphenylphosphino)ferrocene) | CAS 12150-46-8 | ≥97%

DPPF (1,1′-Bis(diphenylphosphino)ferrocene; (ferrocene-1,1′-diyl)bis(diphenylphosphane)) is the canonical ferrocene-backbone bidentate diphosphine in homogeneous transition-metal catalysis. The two -PPh2 donors sit on opposite cyclopentadienyl rings of the ferrocene scaffold, and the conformational flexibility of the Cp–Fe–Cp axis allows the P–M–P bite angle to span from a calculated natural value of ~96° and a mean X-ray value of ~99° out to ~105° in five-coordinate complexes — intermediate between narrow-bite-angle diphosphines such as dppe (~85°) and dppp (~91°) and the rigid wide-bite-angle Xantphos (~111°). The supplied compound is an orange to amber crystalline solid with useful bench stability, but slowly oxidises to phosphine oxide on prolonged air exposure. It melts at 181–183 °C and dissolves in dichloromethane, chloroform, toluene, benzene and warm tetrahydrofuran. The Fe(II)/Fe(III) redox couple of the ferrocenyl backbone makes DPPF a benchmark redox-active diphosphine and a building block for redox-switchable transition-metal complexes.

Pd cross-coupling and (DPPF)MX2 precatalysts. The (dppf)PdCl2 precatalyst and its dichloromethane adduct are among the most widely used bench-stable Pd(II) sources for cross-coupling chemistry, generating catalytically active Pd(0)/DPPF species under the reducing conditions of the relevant coupling manifold. The system supports Pd-catalysed Suzuki–Miyaura coupling — particularly B-alkyl Suzuki–Miyaura couplings of alkylboranes, alkylboronic acids and alkyltrifluoroborates with aryl halides and triflates — together with Negishi alkyl–aryl coupling, Stille coupling, Sonogashira coupling and the Heck reaction. The closely related (DPPF)NiCl2 catalyst is a foundational catalyst class for Kumada–Tamao–Corriu cross-coupling of secondary and tertiary alkyl Grignard reagents with aryl and alkenyl halides, anchored to the pioneering work of Hayashi, Konishi, Kumada and co-workers in the early 1980s.

Pd-catalysed C–N coupling and α-arylation of carbonyls. DPPF was one of the earliest chelating diphosphines shown to support Pd-catalysed Buchwald–Hartwig coupling of primary and secondary amines with aryl bromides, and the (dppf)Pd system remains a reliable choice for amination of simpler aryl halide substrates. The ferrocenyl bite-angle profile was also pivotal in opening the field of Pd-catalysed α-arylation of carbonyl compounds: chelating bisphosphines such as DPPF and its di-o-tolyl analogue (DTPF) suppress β-hydride elimination from the intermediate aryl–Pd–enolate by enforcing a four-coordinate geometry, allowing reductive elimination to deliver α-aryl ketones, esters, amides, nitriles and cyanoacetates. More sterically demanding ferrocenyl phosphine analogues, in particular Q-Phos and the di-tert-butylphosphino variant DtBPF, have extended the substrate scope to less reactive aryl chlorides.

Redox-active ferrocenyl backbone and the chiral ferrocenyl bisphosphine family. The Fe(II)/Fe(III) redox couple of the ferrocenyl backbone is reversible and electrochemically well-defined, and oxidation of DPPF to the corresponding ferrocenium dication is used to modulate metal–phosphine donor properties for redox-switchable catalysis and as a mechanistic probe of phosphine binding to transition-metal centres. DPPF is itself achiral (planar cyclopentadienyl rings, no stereogenic elements), but serves as the achiral benchmark member of the broader ferrocenyl bisphosphine family that includes the 1,1′-disubstituted chiral diphosphines Walphos and Mandyphos and the planar-chiral 1,2-disubstituted Josiphos family developed as privileged ligands for industrial asymmetric hydrogenation.