- Hydrophosphination of Activated Alkenes by a Cobalt(I) Pincer Complex
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Herein we report the synthesis of three heteroleptic first-row transition metal(II) complexes containing carbazolido NNN pincer ligands and conversion to the corresponding metal(I)-carbonyl complexes via a reductive carbonylation route. These complexes are precatalysts for the hydrophosphination of activated alkenes, affording a cobalt-catalysed hydrophosphination process that solely and selectively yields the β addition (anti-Markovnikov) product. The scope of this transformation has been investigated using a variety of activated alkenes. Isolation and characterisation of substrate-coordinated intermediates reveal available coordination sites, which provide insight into the proposed catalytic cycle. (Figure presented.).
- Nolla-Saltiel, Roberto,Geer, Ana M.,Taylor, Laurence J.,Churchill, Olivia,Davies, E. Stephen,Lewis, William,Blake, Alexander J.,Kays, Deborah L.
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p. 3148 - 3157
(2020/06/08)
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- Lanthanum-Catalyzed Regioselective Anti-Markovnikov Hydrophosphinylation of Styrenes
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A useful and convenient method for sp3 C-P(O) bond formation via direct regioselective hydrophosphinylation of simple and readily available alkenes using a lanthanum-based N,N-dimethylbenzylamine complex (La(DMBA)3) as a precatalyst is demonstrated. The reaction proceeds with perfect atom economy for a wide range of styrenes with secondary phosphine oxides, giving moderate to excellent yields.
- Rina, Yesmin Akter,Schmidt, Joseph A. R.
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p. 4261 - 4270
(2019/10/28)
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- Direct C-OH/P(O)-H dehydration coupling forming phosphine oxides
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A t-BuONa-mediated C-OH/P(O)-H cross dehydration coupling to produce alkylphosphine oxides is developed. This reaction employed readily available alcohols and P(O)-H compounds as the starting materials, providing an efficient alternative method for constructing sp3 C-P bonds. A reasonable reaction path involving dehydration and subsequent regio-selective hydrophosphorylation of the resulting alkenes was proposed.
- Chen, Long,Zhu, Yueyue,Chen, Tieqiao,Liu, Long,Zhang, Ji-Shu,Han, Li-Biao
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supporting information
p. 5090 - 5093
(2018/07/29)
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- A silver-initiated free-radical intermolecular hydrophosphinylation of unactivated alkenes
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A scalable, operationally easy intermolecular hydrophosphinylation of various unactivated alkenes with H-P(O) compounds via an Ag(i)-initiated free radical process was developed. Mechanistic studies including electron-spin-resonance (ESR) and radical clock experiments suggest that atom transfer processes were involved in this system.
- Li, Zejiang,Fan, Fenghua,Zhang, Zengyan,Xiao, Yingxia,Liu, Dong,Liu, Zhong-Quan
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p. 27853 - 27856
(2015/03/31)
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- Copper-catalyzed hydrophosphinations of styrenes in water at room temperature
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Copper-catalyzed hydrophosphinations of styrenyl systems in water, at room temperature is herein reported, enabled by our 'designer' surfactant TPGS-750-M. This is an attractive alternative to the more common Pd and Pt catalyzed versions.
- Isley, Nicholas A.,Linstadt, Roscoe T. H.,Slack, Eric D.,Lipshutz, Bruce H.
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p. 13196 - 13200
(2014/11/08)
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- Air-induced anti-Markovnikov addition of secondary phosphine oxides and H-phosphinates to alkenes
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(Chemical Equation Presented) Air (oxygen) induces the addition of secondary phosphine oxides and H-phosphinates to alkenes to selectively produce the corresponding anti-Markovnikov adducts in good to high yields. Mechanistic studies show that the addition probably proceeds via a radical chain mechanism.
- Hirai, Takayoshi,Han, Li-Biao
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- Microwave-assisted regioselective addition of P(O)-H bonds to alkenes without added solvent or catalyst
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(Chemical Equation Presented) The addition of P(O)-H bonds to alkenes has been accomplished using microwave irradiation in the absence of added solvent and catalyst. In addition to single addition reactions, tandem hydrophosphinylation reactions with alky
- Stockland Jr., Robert A.,Taylor, Ross I.,Thompson, Laura E.,Patel, Priti B.
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p. 851 - 853
(2007/10/03)
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- PROTONATION OF PHOSPHINYLMETHYLPYRIDINES AND THEIR N-OXIDES IN NITROMETHANE
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The protonation of phosphinylmethylpyridines with different structures and their N-oxides differing both in the nature and the number of functional groups (pyridine nitrogen, N -> O, and P=O) was studied by potentiometric titration in nitromethane and IR spectroscopy.Regardless of the number of P=O groups, all the investigated phosphinylmethylpyridines were N bases, and their pK values changed in the range 10.4-4.7.In the case of N-oxides of phosphinylmethylpyridines, the oxygen atoms of N -> O and P=O groups participated simultaneously in protonation, and the pK values were 6.7-5.0.The structure of the protonation products is discussed.
- Matrosov, E. I.,Matveeva, A. G.,Bodrin, G. V.,Shcherbakov, B. K.,Polikarpov, Yu. M.,Kabachnik, M. I.
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p. 818 - 823
(2007/10/02)
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- A Functionalized Alkyldiphenylphosphine as an Efficient and Mild Reagent in CCl4-Promoted Substitution Reactions: Kinetics and Mechanism of the Reaction in CHCl3
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(Pyrid-2-ylethyl)diphenylphosphine can be used at 35-45 deg C in carbon tetrachloride-chloroform to give high yields of primary and secondary alkyl chlorides from the corresponding alcohols. The isolation of products is simplified by removal of the phosphorus-containing products by extraction into a dilute aqueous acid solution.The complex reaction was studied by 31P NMR.The rate constants based on the decay of phosphine are reported.The rapid conversion of alcohols proceeds equally via chlorination by CCl3 (path A) and by Cl (path B).The rates of formation and decay of an isobutoxyphosphonium intermediate, Cl, have been measured with 31P NMR.
- Toto, Susan D.,Doi, Joyce Takahashi
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p. 4999 - 5003
(2007/10/02)
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