Related Experiment Video
Updated: Apr 18, 2026
Preparation and Use of Carbonyl-decorated Carbenes in the Activation of White Phosphorus
Published on: October 3, 2014
A Revisit of Co(PMe3)4‑Catalyzed Hydrophosphination of Phenylacetylene with HPPh2
J P I Dulmini Jayawardhena1, Jeanette A Krause1, Hairong Guan1
1Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221-0172, United States.
Abstract:
The low-valent cobalt complex Co-(PMe3)4 was previously reported to catalyze the hydrophosphination of phenylacetylene with HPPh2 to yield (E)-PhCHCH-(PPh2) exclusively. This work provides a more in-depth analysis of the catalytic system showing that Co-(PMe3)4 is contaminated with HCo-(PMe3)4. The impurity undergoes a reversible ligand exchange reaction with HPPh2 to form a series of new cobalt hydrides with the formula HCo-(PMe3)4-x(HPPh2) x (x = 1-4). One of these hydride complexes, namely, HCo-(PMe3)3(HPPh2), features a doublet of quartets for the hydride resonance, which was previously misassigned to the paramagnetic Co-(II) complex, HCo-(PMe3)3(PPh2). The contaminated Co-(PMe3)4 reacts with HPPh2, under heating, to generate a dinuclear cobalt complex, (Me3P)2Co-(μ-PPh2)2Co-(PMe3)2. In addition to "Co-(PMe3)4", the independently synthesized HCo-(PMe3)4, HCo-(HPPh2)4, and (Me3P)2Co-(μ-PPh2)2Co-(PMe3)2 all prove to be catalytically competent. Regardless of the cobalt catalysts examined herein, both (Ph2P)-CPhCH2 and (Z)-PhCHCH-(PPh2) are present as minor hydrophosphination products.
More Related Videos
08:46Preparation and Reactivity of a Triphosphenium Bromide Salt: A Convenient and Stable Source of PhosphorusI
Published on: November 22, 2016
![Mizoroki-Heck Cross-coupling Reactions Catalyzed by Dichloro{bis[1,1',1''-phosphinetriyltripiperidine]}palladium Under Mild Reaction Conditions](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F51444.jpg&w=3840&q=50)
11:44Mizoroki-Heck Cross-coupling Reactions Catalyzed by Dichloro{bis[1,1',1''-phosphinetriyltripiperidine]}palladium Under Mild Reaction Conditions
Published on: March 20, 2014
Related Concept Videos
01:27Benzene to Phenol via Cumene: Hock Process
01:10Hydrolysis of Chlorobenzene to Phenol: Dow Process
02:24Reduction of Alkynes to cis-Alkenes: Catalytic Hydrogenation
Like alkenes, alkynes can be reduced to alkanes in the presence of transition metal catalysts such as Pt, Pd, or Ni. The reaction involves two sequential syn additions of hydrogen via a cis-alkene intermediate.
01:15α-Bromination of Carboxylic Acids: Hell–Volhard–Zelinski Reaction
01:14Aldehydes and Ketones to Alkenes: Wittig Reaction Mechanism
The reaction begins with the nucleophilic addition between a phosphorus ylide and the carbonyl compound. Due to its carbanionic character, phosphorus ylide acts as a strong nucleophile and attacks the electrophilic carbonyl group. This generates a charge-separated dipolar intermediate called betaine. The negatively charged oxygen atom...
02:47Alkynes to Aldehydes and Ketones: Hydroboration-Oxidation
One of the convenient methods for the preparation of aldehydes and ketones is via hydration of alkynes. Hydroboration-oxidation of alkynes is an indirect hydration reaction in which an alkyne is treated with borane followed by oxidation with alkaline peroxide to form an enol that rapidly converts into an aldehyde or a ketone. Terminal alkynes form aldehydes, whereas internal alkynes give ketones as the final product.