Palladium-catalyzed Nucleophilic Substitution of Diarylmethyl Carbonates with Malonate Carbanions

Kuwano, Ryoichi; Kusano, Hiroki

doi:10.1246/cl.2007.528

Cited by 30 publications

(10 citation statements)

References 13 publications

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“…Specifically, we evaluated the parent xantphos ligands L2 and L2’ , containing diphenylphosphino groups (Table 4, entries 3 and 4),54 and Cy-xantphos L3 ,55 containing dicyclohexylphosphino groups (entry 5). Reactions catalyzed by complexes of these ligands occurred with lower conversions and selectivity than those catalyzed by the complex of bis(diethylamino) xantphos L1 or L1’ (entries 1 and 2).…”

Section: Effect Of Phosphine Ligand On Hydroamination Reactivitymentioning

confidence: 99%

Intramolecular Hydroamination of Unbiased and Functionalized Primary Aminoalkenes Catalyzed by a Rhodium Aminophosphine Complex

2010

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We report a rhodium catalyst that exhibits high reactivity for the hydroamination of primary aminoalkenes that are unbiased toward cyclization and that possess functional groups that would not be tolerated in hydroaminations catalyzed by more electrophilic systems. This catalyst contains an unusual diaminophosphine ligand that binds to rhodium in a κ 3 -P,O,P mode. The reactions catalyzed by this complex typically proceed at mild temperatures (room temperature to 70 °C), occur with primary aminoalkenes lacking substituents on the alkyl chain that bias the system toward cyclization, occur with primary aminoalkenes containing chloride, ester, ether, enolizable ketone, nitrile, and unprotected alcohol functionality, and occur with primary aminoalkenes containing internal olefins. Mechanistic data imply that these reactions occur with a turnover-limiting step that is different from that of reactions catalyzed by late transition metal complexes of Pd, Pt, and Ir. This change in the turnover-limiting step and resulting high activity of the catalyst stem from favorable relative rates for protonolysis of the M-C bond to release the hydroamination product vs reversion of the aminoalkyl intermediate to regenerate the acyclic precursor. Probes for the origin of the reactivity of the rhodium complex of L1 imply that the aminophosphine groups lead to these favorable rates by effects beyond steric demands and simple electron donation to the metal center.

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Section: Effect Of Phosphine Ligand On Hydroamination Reactivitymentioning

confidence: 99%

Intramolecular Hydroamination of Unbiased and Functionalized Primary Aminoalkenes Catalyzed by a Rhodium Aminophosphine Complex

2010

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“…Outstanding studies by the groups of Fiaud, Kwano, and Tunge provided some resolution to this restriction; [3] however, the generation of enantioenriched products remains a major challenge. Focusing on the generation of stereochemistry at the electrophilic carbon atom, noteworthy contributions from Fiaud and Hirano/Murai have described the use of secondary benzyl electrophiles in reactions that proceed by partial kinetic resolution or by a dynamic kinetic asymmetric transformation (DYKAT), respectively.…”

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confidence: 99%

Enantioselective α‐Benzylation of Acyclic Esters Using π‐Extended Electrophiles

et al. 2018

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The first asymmetric cooperative Lewis base/palladium catalyzed benzylic alkylation of acyclic esters is reported. This reaction proceeds via stereodefined C1-ammonium enolate nucleophiles. Critical to its success was the identification of benzylic phosphate electrophiles, which were uniquely reactive. Alkylated products were obtained with very high levels of enantioselectivity, and this method has been applied toward the synthesis of the thrombin inhibitor DX-9065a.

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“…[24] At 120°C in DMF, methyl diphenylmethyl carbonate reacted with malonate anion, mainly to afford a mixture of dimethyl 2-benzhydrylmalonate and bis(diphenylmethyl) ether, the ratio between these two products being highly dependent on the added ligand [Equation (13)]. The ether could be formed by addition of diphenylmethoxide, pro-oring this addition [Equation (13) [(η 3 -allyl)Pd(cod)]BF 4 /DPPF catalysis and basic conditions in THF [Equation (15)].…”

Section: Intermolecular Reactions A) Hydroxy Derivative As Leaving Groupmentioning

confidence: 99%

Production of Csp³–Csp³ Bonds through Palladium‐Catalyzed Tsuji–Trost‐Type Reactions of (Hetero)Benzylic Substrates

Bras

Мuzart

2016

Eur J Org Chem

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This review covers the formation of Csp 3 -Csp 3 bonds through Pd-catalyzed reactions of benzylic and heterobenzylic substrates bearing acetate, carbonate, phosphonate, or halide leaving groups, with malonate-type compounds, oxazoles, aldehydes, α, -unsaturated aldehydes, oxindoles, or azlactones. Some of these coupling reactions have been carried out efficiently under enantioselective conditions. In most cases the reaction involves nucleophilic addition to the η 3 -benzylpalladium intermediate formed by elimination of the leaving group. Before

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Palladium-catalyzed Nucleophilic Substitution of Diarylmethyl Carbonates with Malonate Carbanions

Abstract: The nucleophilic substitution of diarylmethyl carbonates with malonate carbanions proceeded in the presence of [Pd(π-C3H5)(cod)]BF4–Cy-Xantphos, giving the desired (diarylmethyl)malonates in up to 90% yield. The yield was extremely affected by choice of the phosphine ligand.

Cited by 30 publications

References 13 publications

Intramolecular Hydroamination of Unbiased and Functionalized Primary Aminoalkenes Catalyzed by a Rhodium Aminophosphine Complex

Intramolecular Hydroamination of Unbiased and Functionalized Primary Aminoalkenes Catalyzed by a Rhodium Aminophosphine Complex

Enantioselective α‐Benzylation of Acyclic Esters Using π‐Extended Electrophiles

Production of Csp³–Csp³ Bonds through Palladium‐Catalyzed Tsuji–Trost‐Type Reactions of (Hetero)Benzylic Substrates

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Palladium-catalyzed Nucleophilic Substitution of Diarylmethyl Carbonates with Malonate Carbanions

Abstract: The nucleophilic substitution of diarylmethyl carbonates with malonate carbanions proceeded in the presence of [Pd(π-C3H5)(cod)]BF4–Cy-Xantphos, giving the desired (diarylmethyl)malonates in up to 90% yield. The yield was extremely affected by choice of the phosphine ligand.

Cited by 30 publications

References 13 publications

Intramolecular Hydroamination of Unbiased and Functionalized Primary Aminoalkenes Catalyzed by a Rhodium Aminophosphine Complex

Intramolecular Hydroamination of Unbiased and Functionalized Primary Aminoalkenes Catalyzed by a Rhodium Aminophosphine Complex

Enantioselective α‐Benzylation of Acyclic Esters Using π‐Extended Electrophiles

Production of Csp3–Csp3 Bonds through Palladium‐Catalyzed Tsuji–Trost‐Type Reactions of (Hetero)Benzylic Substrates

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Production of Csp³–Csp³ Bonds through Palladium‐Catalyzed Tsuji–Trost‐Type Reactions of (Hetero)Benzylic Substrates