Year: 2026
Type: article
Abstract: High Resolution Image Download MS PowerPoint Slide The low-valent cobalt complex Co(PMe 3 ) 4 was previously reported to catalyze the hydrophosphination of phenylacetylene with HPPh 2 to yield ( E )-PhCH═CH(PPh 2 ) exclusively. This work provides a more in-depth analysis of the catalytic system showing that Co(PMe 3 ) 4 is contaminated with HCo(PMe 3 ) 4 . The impurity undergoes a reversible ligand exchange reaction with HPPh 2 to form a series of new cobalt hydrides with the formula HCo(PMe 3 ) 4–x (HPPh 2 ) x ( x = 1–4). One of these hydride complexes, namely, HCo(PMe 3 ) 3 (HPPh 2 ), features a doublet of quartets for the hydride resonance, which was previously misassigned to the paramagnetic Co(II) complex, HCo(PMe 3 ) 3 (PPh 2 ). The contaminated Co(PMe 3 ) 4 reacts with HPPh 2, under heating, to generate a dinuclear cobalt complex, (Me 3 P) 2 Co(μ-PPh 2 ) 2 Co(PMe 3 ) 2 . In addition to “Co(PMe 3 ) 4 ”, the independently synthesized HCo(PMe 3 ) 4, HCo(HPPh 2 ) 4, and (Me 3 P) 2 Co(μ-PPh 2 ) 2 Co(PMe 3 ) 2 all prove to be catalytically competent. Regardless of the cobalt catalysts examined herein, both (Ph 2 P)CPh═CH 2 and ( Z )-PhCH═CH(PPh 2 ) are present as minor hydrophosphination products.
Source: Organometallics
Institution: University of Cincinnati
Language: English
Subfield: Organic Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,500
Awards: G2495953498, CAS: Catalysis with Cobalt Hydrides, G3419035569, G4000266643, MRI: SusChEM: Acquisition of a 400 MHz Nuclear Magnetic Resonance (NMR) Spectrometer for Research and Education, MRI: Acquisition of a Single-Crystal X-ray Diffractometer for Chemical Crystallography Research and Training, G7743108755, G8702519741, G8873201658
OpenAlex ID: W7140080670