Gallium‐Assisted Transfer Hydrogenation of Alkenes

Michelet, Bastien; Bour, Christophe; Gandon, Vincent

doi:10.1002/chem.201404139

Cited by 60 publications

(53 citation statements)

References 70 publications

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“…[14] The present approach relies on hydride abstraction from cyclohexa-1,4-dienes by the boron Lewis acid B(C 6 F 5 ) 3 ,a nd the whole process passes through cationic intermediates until terminated by hydride transfer from [HB(C 6 F 5 ) 3 ]…”

Section: Angewandte Chemiementioning

confidence: 99%

B(C₆F₅)₃‐Catalyzed Transfer of Dihydrogen from One Unsaturated Hydrocarbon to Another

Chatterjee

Grimme

et al. 2015

Angew Chem Int Ed

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A transition-metal-free transfer hydrogenation of 1,1-disubstituted alkenes with cyclohexa-1,4-dienes as the formal source of dihydrogen is reported. The process is initiated by B(C6 F5 )3 -mediated hydride abstraction from the dihydrogen surrogate, forming a Brønsted acidic Wheland complex and [HB(C6 F5 )3 ](-) . A sequence of proton and hydride transfers onto the alkene substrate then yields the alkane. Although several carbenium ion intermediates are involved, competing reaction channels, such as dihydrogen release and cationic dimerization of reactants, are largely suppressed by the use of a cyclohexa-1,4-diene with methyl groups at the C1 and C5 as well as at the C3 position, the site of hydride abstraction. The alkene concentration is another crucial factor. The various reaction pathways were computationally analyzed, leading to a mechanistic picture that is in full agreement with the experimental observations.

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Section: Angewandte Chemiementioning

confidence: 99%

B(C₆F₅)₃‐Catalyzed Transfer of Dihydrogen from One Unsaturated Hydrocarbon to Another

Chatterjee

Grimme

et al. 2015

Angew Chem Int Ed

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“…[7] Our research group is interested in the use of Lewis superacids [8] in molecular catalysis, notably N-heterocyclic carbene gallium complexes of type [(NHC)GaX 2 ][SbF 6 ]( X=Cl, Br,I ). [9,10] These compounds are typicallyp repared by mixing (NHC)GaX 3 and AgSbF 6 in 1,2-dichloroethane at room temperature. After applying this protocol to IPr·InBr 3 (IPr = 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene), [11] we unexpectedly observed the presence of HSbF 6 in the crystals grown from the reaction mixture.…”

mentioning

confidence: 99%

First Evidence for the Existence of Hexafluoroantimonic(V) Acid

Bour

Guillot

Gandon

2015

Chemistry A European J

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By reacting IPr⋅InBr3 with AgSbF6 in dichloroethane at room temperature, we could obtain single crystals comprising [{(IPr⋅InBr3 )(Ag⋅(CH2 Cl)2 )}2 ][SbF6 ]2 (1) and two identical HSbF6 units. It is presumed that the reaction gave rise to [IPr⋅InBr3-x ][SbF6 ]x (x=1, 2, or 3) which reacted with adventitious water to give HSbF6 and [IPr⋅InBr3-x (OH)][SbF6 ]x-1 . The experiment was reproduced at 60 °C, eventually leading to the indium hydroxide [{IPr⋅In(OH)0.5 (H2 O)4.5 }2 ][SbF6 ]5 (2).

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“…Cyclization of an alkyl terminated alkyne, 1q,w as achieved with BCl 3 ,b ut in addition to the borylated dihydronaphthalene product (2q)aborylated naphthalene and tetralin were produced, consistent with transfer hydrogenation proceeding under these reaction conditions. [18] When cyclization was repeated with BCl 3 and TBP, 2q was isolated in a6 7% yield, thus confirming that aryl groups for the stabilization of vinyl cations are not essential for BCl 3 -induced cyclization. TBP/BCl 3 also enabled the cyclization of alkynes substituted with naphthyl and vinyl groups to form 2r and 2s,respectively.Inthe absence of TBP lower yields were observed.…”

Section: Angewandte Zuschriftenmentioning

confidence: 78%

Formation of C(sp²)Boronate Esters by Borylative Cyclization of Alkynes Using BCl₃

et al. 2015

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BCl 3 is an inexpensive electrophile whichinduces the borylative cyclization of awide range of substituted alkynes to regioselectively form polycycles containing synthetically versatile C(sp 2 )Àboronate esters.I tp roceeds rapidly,w ith good yields and is compatible with arange of functional groups and substitution patterns.I ntermolecular 1,2-carboboration of alkynes is also achieved using BCl 3 to generate trisubstituted vinyl boronate esters.

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Gallium‐Assisted Transfer Hydrogenation of Alkenes

Cited by 60 publications

References 70 publications

B(C₆F₅)₃‐Catalyzed Transfer of Dihydrogen from One Unsaturated Hydrocarbon to Another

B(C₆F₅)₃‐Catalyzed Transfer of Dihydrogen from One Unsaturated Hydrocarbon to Another

First Evidence for the Existence of Hexafluoroantimonic(V) Acid

Formation of C(sp²)Boronate Esters by Borylative Cyclization of Alkynes Using BCl₃

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Gallium‐Assisted Transfer Hydrogenation of Alkenes

Cited by 60 publications

References 70 publications

B(C6F5)3‐Catalyzed Transfer of Dihydrogen from One Unsaturated Hydrocarbon to Another

B(C6F5)3‐Catalyzed Transfer of Dihydrogen from One Unsaturated Hydrocarbon to Another

First Evidence for the Existence of Hexafluoroantimonic(V) Acid

Formation of C(sp2)Boronate Esters by Borylative Cyclization of Alkynes Using BCl3

Contact Info

Product

Resources

About

B(C₆F₅)₃‐Catalyzed Transfer of Dihydrogen from One Unsaturated Hydrocarbon to Another

B(C₆F₅)₃‐Catalyzed Transfer of Dihydrogen from One Unsaturated Hydrocarbon to Another

Formation of C(sp²)Boronate Esters by Borylative Cyclization of Alkynes Using BCl₃