Catalytic Asymmetric Synthesis of Quaternary Carbon Centers. Exploratory Studies of Intramolecular Heck Reactions of (<i>Z</i>)-α,β-Unsaturated Anilides and Mechanistic Investigations of Asymmetric Heck Reactions Proceeding via Neutral Intermediates

Ashimori, Atsuyuki; Bachand, Benoit; Calter, c Michael A.; Govek, Steven P.; Overman, Larry E.; d, Daniel J. Poon

doi:10.1021/ja980787h

Cited by 201 publications

(127 citation statements)

References 51 publications

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“…[181][182][183] It is based on versatile, asymmetric preparation of HPIs having carbon substituents at C 3a , starting from (Z)-butenoic acid 151 and N-methyl-p-anisidine (154). The central step is catalytic asymmetric Heck cyclization of (Z)-2-methyl-2-butenanilide (155) to form oxindole aldehyde (S)-149.…”

Section: Wwwchemeurjorgmentioning

confidence: 99%

Structure, Bioactivity and Synthesis of Natural Products with Hexahydropyrrolo[2,3‐b]indole

Ruiz-Sanchis

Savina

Alberício

et al. 2011

Chemistry A European J

450

199

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Research on natural products containing hexahydropyrrolo[2,3-b]indole (HPI) has dramatically increased during the past few years. Newly discovered natural products with complex structures and important biological activities have recently been isolated and synthesized. This review summarizes the structures, biological activities, and synthetic routes for natural compounds containing HPI, emphasizing the different strategies for assembling this motif. It covers a broad range of molecules, from small alkaloids to complex peptides.

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Section: Wwwchemeurjorgmentioning

confidence: 99%

Structure, Bioactivity and Synthesis of Natural Products with Hexahydropyrrolo[2,3‐b]indole

Ruiz-Sanchis

Savina

Alberício

et al. 2011

Chemistry A European J

450

199

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“…In diesem Zusammenhang ist eine intramolekulare decarboxylierende allylische Amidierung [298,[307][308][309] auf der Basis des Iridium/Phosphoramidit-Katalysatorsystem zu erwähnen (Schema 59). [310,311] …”

Section: Asymmetrische Allylische Alkylierungenunclassified

Phosphoramidite: privilegierte Liganden in der asymmetrischen Katalyse

2010

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Die asymmetrische Katalyse mit Übergangsmetallkomplexen ist die Grundlage unzähliger stereoselektiver Umwandlungen und hat damit das Bild der modernen Synthesechemie gewandelt. Der Schlüssel zum Erfolg war die Entwicklung chiraler Liganden zur Kontrolle der Regio‐, Diastereo‐ und Enantioselektivität. Dabei haben sich Phosphoramidite als eine äußerst vielseitige und leicht zugängliche Klasse von chiralen Liganden erwiesen. Ihre modulare Struktur ermöglicht die Herstellung von Ligandenbibliotheken und erleichtert die Feinabstimmung für eine bestimmte katalytische Reaktion. Phosphoramidite bewirken oft außerordentlich hohe Stereoselektivitäten, und ihre einzähnige Natur ist in der kombinatorischen Katalyse, die gemischte Liganden verwendet, unverzichtbar. In diesem Aufsatz werden neue Entwicklungen in der asymmetrischen Katalyse mit Phosphoramiditen diskutiert, wobei der Schwerpunkt auf der Bildung von Kohlenstoff‐ Kohlenstoff‐ und Kohlenstoff‐Heteroatom‐Bindungen liegt.

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“…[21] Whereas examples of enantioselective Heck cyclization-anion capture of resulting p-allyl-Pd II complexes are known, [22] to the best of our knowledge, the corresponding enantioselective Heck cyclization-anion capture of the resulting s-alkyl-Pd II complex is unknown. Initial investigations into reaction conditions using (R)-BINAP (see Figure 1, below), a highly efficient ligand in oxindole synthesis, [23] are summarized in Table 3. The domino sequence of 5 k proceeded efficiently in the presence of (R)-BINAP to provide 1 k in 90 % yield although the enantioselectivities achieved remained low (entry 1).…”

Section: Introductionmentioning

confidence: 99%

Palladium‐Catalyzed Enantioselective Domino Heck–Cyanation Sequence: Development and Application to the Total Synthesis of Esermethole and Physostigmine

Pinto¹,

Jia²,

Neuville³

et al. 2007

Chemistry A European J

269

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An efficient synthesis of functionalized 3-alkyl-3-cyanomethyl-2-oxindole 1 by a palladium-catalyzed domino Heck-cyanation reaction has been developed. Reaction of ortho-iodoanilide 5 with potassium ferro(II)cyanide, K(4)[Fe(CN)(6)], dissolved in DMF in the presence of palladium acetate and sodium carbonate afforded oxindole 1 in good to excellent yields. An enantioselective domino Heck-cyanation process has been developed for the first time using (S)-DIFLUORPHOS as a chiral supporting ligand, and an enantioselectivity of up to 79 % ee in the enantiomerically enriched oxindole was obtained under optimized conditions. A concise total synthesis of esermethole and physostigmine, powerful inhibitors of acetyl- and butyryl-cholinesterase, is documented.

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Catalytic Asymmetric Synthesis of Quaternary Carbon Centers. Exploratory Studies of Intramolecular Heck Reactions of (Z)-α,β-Unsaturated Anilides and Mechanistic Investigations of Asymmetric Heck Reactions Proceeding via Neutral Intermediates

Cited by 201 publications

References 51 publications

Structure, Bioactivity and Synthesis of Natural Products with Hexahydropyrrolo[2,3‐b]indole

Structure, Bioactivity and Synthesis of Natural Products with Hexahydropyrrolo[2,3‐b]indole

Phosphoramidite: privilegierte Liganden in der asymmetrischen Katalyse

Palladium‐Catalyzed Enantioselective Domino Heck–Cyanation Sequence: Development and Application to the Total Synthesis of Esermethole and Physostigmine

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