34478-62-1Relevant articles and documents
Reactions of Low-Coordinate Cobalt(0)-N-Heterocyclic Carbene Complexes with Primary Aryl Phosphines
Wang, Dongyang,Chen, Qi,Leng, Xuebing,Deng, Liang
supporting information, p. 15600 - 15609 (2019/01/04)
Aiming to get knowledge on the reactivity of low-coordinate cobalt(0) species toward primary phosphines, the reactions of [(IPr)Co(vtms)2] and [(ICy)2Co(vtms)] (IPr = 1,3-bis(2′,6′-diisopropylphenyl)imidazol-2-ylidene, ICy = 1,3-dicyclohexylimidazol-2-ylidene, and vtms = vinyltrimethylsilane) with several primary aryl phosphines have been examined. The reactions of [(IPr)Co(vtms)2] and [(ICy)2Co(vtms)] with H2PDmp (Dmp = 2,6-dimesitylphenyl) at 80 °C furnish the diamagnetic cobalt(I) phosphido complexes [(NHC)Co(PHDmp)] (NHC = IPr, 1; ICy, 2) that feature the Co-(η6-mesityl) interaction. Complex 1 can coordinate CO to generate the terminal phosphido complex [(IPr)Co(CO)3(PHDmp)] (3) and can be oxidized by [Cp2Fe][BArF4] to yield the cobalt(II) phosphido complex [(IPr)Co(PHDmp)][BArF4] (4, BArF4 = tetrakis(3,5-di(trifluoromethyl)phenyl)borate). For the reactions with sterically less-hindered primary phosphines, [(IPr)Co(vtms)2] is inert toward H2PC6H2-2,4,6-Me3 (H2PMes) at room temperature, whereas [(ICy)2Co(vtms)] can react with H2PMes at room temperature to produce the cobalt(II) phosphido alkyl complex trans-[(ICy)2Co(CH2CH2SiMe3)(PHMes)] (5). At 80 °C, the cobalt(0) alkene complexes [(IPr)Co(vtms)2] and [(ICy)2Co(vtms)] and also the cobalt phosphido complexes, 1, 2, and 5 can serve as precatalysts for the dehydrocoupling reaction of H2PMes to afford MesHPPHMes. NHC-Co(I)-phosphido species are proposed as the in-cycle intermediates for these cobalt-catalyzed dehydrocoupling reactions.
Facile, Catalytic Dehydrocoupling of Phosphines Using β-Diketiminate Iron(II) Complexes
King, Andrew K.,Buchard, Antoine,Mahon, Mary F.,Webster, Ruth L.
supporting information, p. 15960 - 15963 (2015/11/03)
Catalytic dehydrocoupling of primary and secondary phosphines has been achieved for the first time using an iron pre-catalyst. The reaction proceeds under mild reaction conditions and is successful with a range of diarylphosphines. A proton acceptor is not needed for the transformation to take place, but addition of 1-hexene does allow for turnover at 50°C. The catalytic system developed also facilitates the dehydrocoupling of phenylphosphane and dicyclohexylphosphane. A change in solvent switches off dehydrocoupling to allow hydrophosphination of alkenes.
Exploration of tin-catalyzed phosphine dehydrocoupling: Catalyst effects and observation of tin-catalyzed hydrophosphination
Erickson, Karla A.,Dixon, Lily S.H.,Wright, Dominic S.,Waterman, Rory
supporting information, p. 141 - 145 (2015/01/09)
The phosphine substrate scope in dehydrocoupling reactions catalyzed by Cp?2SnCl2 (Cp? = pentamethylcyclopentadienyl, 1) have been explored. Catalyst variants R2SnX2 (R = Cp?, Ph; X = Cl, Me, Ph) were also tested, which revealed that activity is dependent on the Cp? ligands as well as more electron withdrawing X ligands. Steric factors at the phosphine substrate are also important. Compound 1 was found to be a catalyst for hydrophosphination of styrene, 2,3-dimethylbutadiene, and diphenylacetylene with phenylphosphine, which is the first example of a p-block catalyst for hydrophosphination.
