The application of monodentate secondary phosphine oxide ligands in rhodium- and iridium-catalyzed asymmetric hydrogenation

Jiang, Xiao-Bin; Berg, Michel van den; Minnaard, Adriaan J.; Feringa, Ben L.; Vries, Johannes G. de

doi:10.1016/j.tetasy.2004.05.002

Cited by 74 publications

(32 citation statements)

References 45 publications

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“…The superiority of the self assembling mono-anionic chelate O−anionic  1 -P(III)−phosph(in)ito ligands over non-assembled phosphane ligands in alkene hydroformylation [34,35,194,195] alkene, ketone and imine hydrogenation [196][197][198] and nitrile hydration [32,33,199] argues in favour of the bidentate coordination mode of the anionic phosph(in)ito/phosphinous acid chelate ligand being maintained during the catalytic process due to the strength of the intramolecular hydrogen bond. Lately, bidentate mono O−anionic  1 -P(III)−phosph(in)ite complexes have been involved in a large number of catalytic transformations [176,177,[200][201][202][203][204][205][206].…”

Section: Prevalent Activities In Catalysismentioning

confidence: 99%

Anionic phosph(in)ito (“phosphoryl”) ligands: Non-classical “actor” phosphane-type ligands in coordination chemistry

Sutra

Igau

2016

Coordination Chemistry Reviews

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Section: Prevalent Activities In Catalysismentioning

confidence: 99%

Anionic phosph(in)ito (“phosphoryl”) ligands: Non-classical “actor” phosphane-type ligands in coordination chemistry

Sutra

Igau

2016

Coordination Chemistry Reviews

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“…[34] N-or O-Substituted allyllithium compounds may be formed either by a-deprotonation of an allylamine/allyl alcohol derivative or alternatively by g-deprotonation of an enamine/enol derivative. [23] The corresponding N-aryl-(Z)-enol carbamates 19 were made by the method reported by Feringa et al: [35] the sodium enolates of the ketones 18 were O-acylated by addition of the carbamoyl chloride derivatives of N-methyl aniline or N-methyl-4-chloroaniline (Scheme 9). We had previously shown that asymmetric g-deprotonation of an N-carbamoyl enamine (an N-vinyl urea) with chiral lithium amides generates N-substituted allyllithium compounds enantioselectively.…”

mentioning

confidence: 99%

Lithium Choreography: Intramolecular Arylations of Carbamate‐Stabilised Carbanions and Their Mechanisms Probed by In Situ IR Spectroscopy and DFT Calculations

Fournier

Nichols

Vincent

et al. 2012

Chemistry A European J

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Deprotonation of O-allyl, O-propargyl or O-benzyl carbamates in the presence of a lithium counterion leads to carbamate-stabilised organolithium compounds that may be quenched with electrophiles. We now report that when the allylic, propargylic or benzylic carbamate bears an N-aryl substituent, an aryl migration takes place, leading to stereochemical inversion and C-arylation of the carbamate α to oxygen. The aryl migration is an intramolecular S(N) Ar reaction, despite the lack of anion-stabilising aryl substituents. Our in situ IR studies reveal a number of intermediates along the rearrangement pathway, including a "pre-lithiation complex," the deprotonated carbamate, the rearranged anion, and the final arylated carbamate. No evidence was obtained for a dearomatised intermediate during the aryl migration. DFT calculations predict that during the reaction the solvated Li cation moves from the carbanion centre, thus freeing its lone pair for nucleophilic attack on the remote phenyl ring. This charge separation leads to several alternative conformations. The one having Li(+) bound to the carbamate oxygen gives rise to the lowest-energy transition structure, and also leads to inversion of the configuration. In agreement with the IR studies, the DFT calculations fail to locate a dearomatised intermediate.

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“…[9] Our continued interest in the metal-catalyzed cycloaddition reactions between alkynes and norbornadiene [10] prompted us to investigate the catalytic behavior of palladium(ii) complexes coordinated by SPOs.…”

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confidence: 99%

[2+1] Cycloadditions of Terminal Alkynes to Norbornene Derivatives Catalyzed by Palladium Complexes with Phosphinous Acid Ligands

2005

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Secondary phosphine oxides (SPOs) have been widely used for the synthesis of tertiary phosphine oxides and have found applications as Wittig-Horner reagents [1][2] and, later, as effective ligands for transition-metal complexes.[3] Recently, Li et al. showed that SPOs form air-stable palladium complexes, such as POPd1, when they are mixed with PdCl 2 (MeCN) 2 and then treated with Et 3 N.[4] These complexes proved efficient as catalysts in several cross-coupling reactions [4][5] as well as in asymmetric allylic alkylations.[6] Recent reports showed also that these new ligands are suitable for other types of catalyzed reactions such as the hydrolysis of nitriles [7] and the asymmetric hydrogenation of imines [8] and alkenes.[9] Our continued interest in the metal-catalyzed cycloaddition reactions between alkynes and norbornadiene [10] prompted us to investigate the catalytic behavior of palladium(ii) complexes coordinated by SPOs.First, we developed an easier way to synthesize the palladium catalyst 1. Upon treatment of Pd(OAc) 2 with tertbutyl(phenyl)phosphane oxide (L 1), dihydrogen di-macetatotetrakis(tert-butylphenylphosphinito -k -P)dipalladate (1) was quantitatively obtained without further treatment (Scheme 1).[11] Second, as a model we examined the reaction of phenylethyne (3 a) with norbornadiene (2) in the presence of 2.5 mol % of 1 in toluene at 50 8C for 24 h. Unexpectedly, the palladium(ii) complex 1 coordinated by L 1 favored the formation of benzylidenecyclopropane (4 a) as a single diastereomer in 17 % yield (Scheme 2) and contaminated by an unidentified byproduct (5 %). Surprisingly, a similar reaction using the known chloro-bridged analogue 5[6a-12] as catalyst did not work. Furthermore, in the reaction catalyzed by 5, the addition of 10 mol % of AgOAc (4 equiv relative to

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The application of monodentate secondary phosphine oxide ligands in rhodium- and iridium-catalyzed asymmetric hydrogenation

Cited by 74 publications

References 45 publications

Anionic phosph(in)ito (“phosphoryl”) ligands: Non-classical “actor” phosphane-type ligands in coordination chemistry

Anionic phosph(in)ito (“phosphoryl”) ligands: Non-classical “actor” phosphane-type ligands in coordination chemistry

Lithium Choreography: Intramolecular Arylations of Carbamate‐Stabilised Carbanions and Their Mechanisms Probed by In Situ IR Spectroscopy and DFT Calculations

[2+1] Cycloadditions of Terminal Alkynes to Norbornene Derivatives Catalyzed by Palladium Complexes with Phosphinous Acid Ligands

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