Chiral Pd-catalyzed enantioselective Friedel–Crafts reaction of indoles with γ,δ-unsaturated β-keto phosphonates

Kang, Youngcheol; Kwon, Bo Kyung; Mang, Joo Yang; Kim, Dae Young

doi:10.1016/j.tetlet.2011.04.084

Cited by 51 publications

(6 citation statements)

References 61 publications

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“…The Friedel–Crafts (F–C) alkylation reaction is one of the most powerful tools for carbon–carbon bond formation, , which has been widely used to generate important building blocks for organic transformations. − Since the first case of catalytic asymmetric F–C alkylation reaction was reported in the mid-1980s, it has received much attention. Some organocatalysts (such as chiral amines, , thiourea, phosphoric acid, ureas, , cinchona alkaloids, or bissulfonamide), Lewis acidic transition-metal complexes, ,,, as well as supramolecular metal-complexes/DNA catalysts , have been proved to be efficient for catalytic asymmetric F–C alkylation reactions. In these successful cases, the reports involving chalcone derivatives as electrophiles were very limited, owing to their low reactivity and the difficulty in controlling the enantiofacial differentiation. , …”

Section: Introductionmentioning

confidence: 99%

Mechanism and Origins of Stereoinduction in an Asymmetric Friedel–Crafts Alkylation Reaction of Chalcone Catalyzed by Chiral N,N′-Dioxide–Sc(III) Complex

et al. 2018

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The mechanism and selectivity of the asymmetric Friedel-Crafts (F-C) alkylation reaction between indole and chalcone catalyzed by chiral N, N'-dioxide-Sc(III) complexes were investigated at the M06/6-311+G(d,p)//M06/[LANL2DZ,6-31G(d)](SMD,CHCl) level. The reaction occurred via a three-step mechanism: (i) the C-C bond formation by interacting the most mucleophilic C center of indole with the most electrophilic C center of chalcone; (ii) the abstraction of the proton at the C atom of indole by counterion OTf; (iii) proton transfer from HOTf to the C atom of chalcone, generating the F-C alkylation product. The reaction preferred to occur along the favorable re-face attack pathway, producing the dominant R-product. The turnover frequency (TOF) of catalysis was predicted to be 1.59 × 10 s, with a rate constant of K( T) = 1.58 × 10 exp(-29057/ RT) dm·mol·s over the temperature range of 248-368 K. Activation strain model (ASM) and energy decomposition analysis (EDA), as well as noncovalent interaction (NCI) analysis, for the stereocontrolling transition state revealed that the substituent attached to the N atom of the amide subunits as well as the amino acid backbone of ligand played important roles in chiral inductivity. The benzyl group with structural flexibility tended to form strong π-π stacking with substrate as well as the terminal phenyl group of chalcone, stabilizing re-face attack transition state.

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Section: Introductionmentioning

confidence: 99%

Mechanism and Origins of Stereoinduction in an Asymmetric Friedel–Crafts Alkylation Reaction of Chalcone Catalyzed by Chiral N,N′-Dioxide–Sc(III) Complex

et al. 2018

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“…The asymmetric transition metal catalysis, employing transition metal in the presence of chiral ligands, is widely known in the construction of chiral-functionalized indoles. Kim et al disclosed the first utilization of chiral dicationic palladium complex L1 as an efficient catalyst in the asymmetric F–C reaction of indoles 1 with γ,δ-unsaturated β-keto phosphonates 2 . The synthetic strategy produced the corresponding alkylation adducts in fair to high yields and excellent enantioselectivities (up to 99% ee; Scheme a).…”

Section: Conjugate Addition To Electrophilic Cc Bondsmentioning

confidence: 72%

Recent Advances in the Catalytic Asymmetric Friedel–Crafts Reactions of Indoles

2022

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Functionalized chiral indole derivatives are privileged and versatile organic frameworks encountered in numerous pharmaceutically active agents and biologically active natural products. The catalytic asymmetric Friedel–Crafts reaction of indoles, catalyzed by chiral metal complexes or chiral organocatalysts, is one of the most powerful and atom-economical approaches to access optically active indole derivatives. Consequently, a wide range of electrophilic partners including α,β-unsaturated ketones, esters, amides, imines, β,γ-unsaturated α-keto- and α-ketiminoesters, ketimines, nitroalkenes, and many others have been successfully employed to achieve a plethora of functionalized chiral indole moieties. In particular, strategies for C–H functionalization in the phenyl of indoles require incorporation of a directing or blocking group in the phenyl or azole ring of indole. The discovery of chiral catalysts which can control enantiodiscrimination has gained a great deal of attention in recent years. This review will provide an updated account on the application of the asymmetric Friedel–Crafts reaction of indoles in the synthesis of diverse chiral indole derivatives, covering the timeframe from 2011 to today.

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“…In the framework of our research program for the development of synthetic methods for the enantioselective construction of stereogenic carbon centers [ 37 – 42 ], we recently reported the enantioselective Michael addition of active methines to nitroalkenes [ 43 – 44 ]. Herein, we describe the direct enantioselective Michael addition of 2-hydroxy-1,4-naphthoquinone with nitroalkenes, catalyzed by bifunctional organocatalysts ( Fig.…”

Section: Resultsmentioning

confidence: 99%

Enantioselective Michael addition of 2-hydroxy-1,4-naphthoquinones to nitroalkenes catalyzed by binaphthyl-derived organocatalysts

Woo¹,

Kim²

2012

Beilstein J. Org. Chem.

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Chiral Pd-catalyzed enantioselective Friedel–Crafts reaction of indoles with γ,δ-unsaturated β-keto phosphonates

Cited by 51 publications

References 61 publications

Mechanism and Origins of Stereoinduction in an Asymmetric Friedel–Crafts Alkylation Reaction of Chalcone Catalyzed by Chiral N,N′-Dioxide–Sc(III) Complex

Mechanism and Origins of Stereoinduction in an Asymmetric Friedel–Crafts Alkylation Reaction of Chalcone Catalyzed by Chiral N,N′-Dioxide–Sc(III) Complex

Recent Advances in the Catalytic Asymmetric Friedel–Crafts Reactions of Indoles

Enantioselective Michael addition of 2-hydroxy-1,4-naphthoquinones to nitroalkenes catalyzed by binaphthyl-derived organocatalysts

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