Allylic Dearomatization Research Articles

Direct asymmetric dearomatization of pyridines and pyrazines by iridium-catalyzed allylic amination reactions.

The first iridium-catalyzed intramolecular asymmetric allylic dearomatization reaction of pyridines and pyrazines has been realized. 2,3-Dihydroindolizine and 6,7-dihydropyrrolo[1,2-a]pyrazine derivatives were obtained with excellent yields and enantioselectivity. This methodology features dearomatization by direct N-allylic alkylation of pyridines or pyrazines under mild reaction conditions.

Direct Asymmetric Dearomatization of Pyridines and Pyrazines by Iridium‐Catalyzed Allylic Amination Reactions

AbstractThe first iridium‐catalyzed intramolecular asymmetric allylic dearomatization reaction of pyridines and pyrazines has been realized. 2,3‐Dihydroindolizine and 6,7‐dihydropyrrolo[1,2‐a]pyrazine derivatives were obtained with excellent yields and enantioselectivity. This methodology features dearomatization by direct N‐allylic alkylation of pyridines or pyrazines under mild reaction conditions.

Palladium‐Catalyzed Intermolecular Allylic Dearomatization Reaction of α‐Substituted β‐Naphthol Derivatives: Scope and Mechanistic Investigation

AbstractA highly efficient dearomatization reaction of α‐substituted β‐naphthols with excellent chemoselectivity and regioselectivity has been developed. Mechanistic studies demonstrated that the dearomatized alkylation product is the thermodynamically more stable compound. The etherification product could be further transformed to the dearomatization product.magnified image

Highly regio- and enantioselective synthesis of polysubstituted 2H-pyrroles via Pd-catalyzed intermolecular asymmetric allylic dearomatization of pyrroles.

A highly efficient synthesis of chiral polysubstituted 2H-pyrrole derivatives via a Pd-catalyzed intermolecular asymmetric allylic dearomatization reaction of pyrroles is presented. With the commercially available palladium precursor and chiral ligand, the polysubstituted 2H-pyrrole products containing a chiral quaternary carbon center were obtained with up to 97% ee and >95/5 regioselectivity.

ChemInform Abstract: Palladium‐Catalyzed Intermolecular Asymmetric Allylic Dearomatization Reaction of Naphthol Derivatives.

AbstractThis is the first Pd‐catalyzed intermolecular asymmetric allylic dearomatization of β‐naphthol derivatives yielding products with all‐carbon quaternary stereocenters with good enantioselectivities.

Enantioselective Palladium-Catalyzed Allylic Dearomatization

Enantioselective Palladium-Catalyzed Allylic Dearomatization

ChemInform Abstract: Ruthenium‐Catalyzed Intramolecular Allylic Dearomatization Reaction of Indole Derivatives.

AbstractIndoles of type (I) bearing an unsaturated carbonate side chain undergo efficient spirocyclization via a Ru‐catalyzed intramolecular allylic dearomatization.

Ir-catalyzed intermolecular asymmetric allylic dearomatization reaction of indoles

An Ir-catalyzed intermolecular asymmetric dearomatization reaction of substituted indoles with allylic alcohols has been realized to afford the corresponding indoline derivatives in 71–97% yield with up to 98% ee in the presence of the Lewis acid Fe(OTf)2. This methodology features the enantioselective construction of all-carbon quaternary stereogenic centers of prochiral nucleophiles and its utility has been demonstrated in the asymmetric total synthesis of (−)-debromoflustramine B.

Enantioselective Palladium-Catalyzed Allylic Dearomatization

Enantioselective Palladium-Catalyzed Allylic Dearomatization

Palladium‐Catalyzed Intermolecular Asymmetric Allylic Dearomatization Reaction of Naphthol Derivatives

Baring all: The title reaction provides β-naphthalenones bearing an all-carbon quaternary center in good to excellent yields, as well as excellent chemo- and enantioselectivity.

Palladium‐Catalyzed Intermolecular Asymmetric Allylic Dearomatization Reaction of Naphthol Derivatives

Aufgabe erfüllt: Die Titelreaktion liefert β-Naphthalenone mit quartärem Kohlenstoffzentrum in guten bis exzellenten Ausbeuten (siehe Schema). Chemo- und Enantioselektivität sind ebenfalls hervorragend.

Ruthenium-Catalyzed Intramolecular Allylic Dearomatization Reaction of Indole Derivatives

An efficient synthesis of spiroindolenine derivatives via a ruthenium-catalyzed intramolecular allylic dearomatization reaction has been developed. This method features a wide substrate scope, mild reaction conditions, and an operationally simple procedure.

Diversity oriented synthesis of indole-based peri-annulated compounds via allylic alkylation reactions

Diverse indole-based peri-annulated compounds were synthesized via transition-metal-catalyzed allylic alkylation reaction. With palladium catalyst, indole-based nine-membered ring products were obtained in 40–70% yields. When iridium catalyst was used, highly enantioenriched seven-membered ring products were obtained in 40–78% yields and 91–97% ee. Meanwhile, when 3-substituted indole substrates were employed with a palladium catalyst, asymmetric allylic dearomatization of indoles occurred with products obtained in 48–78% yields and 35–78% ee with a chiral ferrocene-based Phox ligand. Interestingly, with an iridium catalyst, Friedel–Crafts type allylic alkylation reaction proceeded at the C5 position of indole, affording the products with 40–60% yields and 56–97% ee.

ChemInform Abstract: Enantioselective Synthesis of Spiro Cyclopentane‐1,3′‐indoles and 2,3,4,9‐Tetrahydro‐1H‐carbazoles by Iridium‐Catalyzed Allylic Dearomatization and Stereospecific Migration.

AbstractIn some cases, the imine functionality of the indolenines, which are obtained from the allylic dearomatization, causes purification difficulties.

Catalytic Asymmetric Allylic Dearomatization of Indoles

Catalytic Asymmetric Allylic Dearomatization of Indoles

Enantioselective Synthesis of Spiro Cyclopentane‐1,3′‐indoles and 2,3,4,9‐Tetrahydro‐1H‐carbazoles by Iridium‐Catalyzed Allylic Dearomatization and Stereospecific Migration

In some cases, the imine functionality of the indolenines, which are obtained from the allylic dearomatization, causes purification difficulties.

Enantioselective Synthesis of Spiro Cyclopentane‐1,3′‐indoles and 2,3,4,9‐Tetrahydro‐1H‐carbazoles by Iridium‐Catalyzed Allylic Dearomatization and Stereospecific Migration

Allyl greift an: Fünfgliedrige Spiroindolenine werden hoch enantioselektiv durch die iridiumkatalysierte intramolekulare allylierende Desaromatisierung von Indolen aufgebaut. Eine stereospezifische Umlagerung der resultierenden Spirocyclopentan-1,3′-indole ergibt enantiomerenangereicherte 2,3,4,9-Tetrahydro-1H-carbazole.

Iridium-Catalyzed Enantioselective Allylic Dearomatization of Phenols

In addition to previous research ­regarding asymmetric dearomatization of phenols (see: Q. Gu, Z.-Q. Rong, C. Zheng, S.-L. You J. Am. Chem. Soc. 2010, 132, 4056), the authors now report an iridium-catalyzed intramolecular ­allylic dearomatization, which provides a direct access to desired spirocyclohexadienones in good to excellent yields and enantioselectivities.

ChemInform Abstract: Iridium‐Catalyzed Intramolecular Asymmetric Allylic Dearomatization of Phenols.

AbstractSpirocyclohexadienone derivatives are obtained in high yields and enantioselectivities by intramolecular asymmetric allylic dearomatization of phenols bearing tethered allylic ethers.

Iridium‐Catalyzed Intramolecular Asymmetric Allylic Dearomatization of Phenols

Spirocyclohexadienone derivatives are obtained in high yields and enantioselectivities by intramolecular asymmetric allylic dearomatization of phenols bearing tethered allylic ethers.