Ir‐Catalyzed Enantioselective Synthesis of gem‐Diborylalkenes Enabled by 1,2‐Boron Shift

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(32)

Опубликована: Июнь 15, 2023

Abstract Asymmetric cross‐couplings based on 1,2‐carbon migration from B‐ate complexes have been developed efficiently to access valuable organoboronates. However, enantioselective reactions triggered by 1,2‐boron shift remained be unaddressed synthetic challenge. Here, Ir‐catalyzed asymmetric allylic alkylation enabled was developed. In this reaction, we disclosed that excellent enantioselectivities were achieved through an interesting dynamic kinetic resolution (DKR) process of carbonates at the elevated temperature. Notably, highly (bis‐boryl)alkenes array diversifications versatile molecules. Extensive experimental and computational studies conducted elucidate reaction mechanism DKR clarify origin enantioselectivities.

Язык: Английский

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Iridium-Catalyzed Diastereo- and Enantioselective [4 + 1] Cycloaddition of Hydroxyallyl Anilines with Sulfoxonium Ylides

Organic Letters, Год журнала: 2023, Номер 25(25), С. 4621 - 4626

Опубликована: Июнь 15, 2023

We present here an iridium-catalyzed diastereo- and enantioselective [4 + 1] cycloaddition reaction of hydroxyallyl anilines with sulfoxonium ylides under mild conditions, leading to 3-vinyl indolines in moderate good yields excellent enantioselectivities. Control experiments disclosed a plausible mechanism.

Язык: Английский

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Regioselective Formal β‐Allylation of Carbonyl Compounds Enabled by Cooperative Nickel and Photoredox Catalysis

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(37)

Опубликована: Май 4, 2023

The Tsuji-Trost reaction between carbonyl compounds and allylic precursors has been widely used in the synthesis of natural products pharmaceutical compounds. As α-C-H bond is far more acidic than β-C-H bond, undergo highly regioselective allylation at α-position their β-allylation therefore challenging. This innate α-reactivity conversely hampers diversity, especially if corresponding product targeted. Herein, we present a formal intermolecular β-C-C formation broad range aldehydes ketones with different allyl electrophiles through cooperative nickel photoredox catalysis. β-Selectivity achieved via initial transformation to silyl enol ethers. overall features mild conditions, excellent regioselectivity, wide functional group tolerance high efficiency. introduced facile proceeding catalysis allows preparation valuable building blocks that are difficult access from using existing methodology.

Язык: Английский

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Ir-Catalyzed Asymmetric Cascade Allylation/Spiroketalization Reaction for Stereoselective Synthesis of Oxazoline-Spiroketals

Organic Letters, Год журнала: 2023, Номер 25(2), С. 325 - 330

Опубликована: Янв. 6, 2023

An asymmetric cascade allylation/spiroketalization reaction between 2-(1-hydroxyallyl)phenols and 5-methyleneoxazolines is accomplished by using a chiral Ir(I) catalyst derived from commercially available iridium precursor the Carreira ligand. This protocol furnishes class of structurally novel unique oxazoline-spiroketals in up to 86% yield, >99% ee >20:1 dr. Moreover, control experiments reveal that 4,4-disubstitution on necessary avoid aromatization for spiroketalization occur. On basis this, plausible mechanism illustrated.

Язык: Английский

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Asymmetric cascades of the π-allyl complex: a journey from transition-metal catalysis to metallaphotocatalysis

Chemical Communications, Год журнала: 2023, Номер 59(76), С. 11298 - 11319

Опубликована: Янв. 1, 2023

The enantioselective catalytic cascade involving Tsuji-Trost allylation has provided a viable strategy for the construction of multiple asymmetric C-C and C-X centres numerous methods have been developed around it synthesis various vital scaffolds. synthetic utility this was enhanced by replacing customary allyl acetates with ethylene diacetates/dicarbonates, vinyl epoxides, oxetanes, carbonates, cyclopropanes, enynes, dienes using transition-metal catalysis. One more milestone achieved when metallaphotocatalysis necessary platform these cascades cheaper metal. This review will provide summary from 2015.

Язык: Английский

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Access to Chiral Oxindoles via Ir-Catalyzed Asymmetric Pudovik Addition/[1,2]-Phospha-Brook Rearrangement/Allylation Cascade

Organic Letters, Год журнала: 2025, Номер unknown

Опубликована: Май 2, 2025

An asymmetric catalytic Pudovik addition/[1,2]-phospha-Brook rearrangement/allylation reaction of readily available isatins, phosphites, and vinyl ethylene carbonate enabled by a chiral iridium catalyst was developed in one-pot fashion. A wide range enantioenriched oxindole derivatives containing two adjacent stereocenters could be obtained good to high yields with excellent diastereoselectivity enantioselectivity (65-99% yield, 7:1 >20:1 dr, generally 99% ee). This cascade protocol owned the advantages starting materials, regio-/diastereo-/enantioselectivity, substrate scope generality.

Язык: Английский

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Enantioselective Synthesis of Ten-Membered Lactones via Palladium-Catalyzed [5 + 5] Annulation

Organic Letters, Год журнала: 2023, Номер 25(12), С. 2030 - 2035

Опубликована: Март 20, 2023

Ten-membered lactones are the core units of many biologically active natural products but with a great synthetic challenge. Based on principle vinylogy, novel types cyclic vinylogous anhydrides have been designed as five-carbon carbonyl synthons, further applied in [5 + 5] annulation vinylethylene carbonates under chiral palladium catalysis. This strategy features excellent regioselectivity, mild conditions, and broad substrate scope, affording range spiro ten-membered bearing oxindole pyrrolidinone motif yield (up to 99%) moderate high enantioselectivity 89% ee).

Язык: Английский

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Iridium/Acid Dual-Catalyzed Enantioselective Aza-ene-type Allylic Alkylation of Nitro Ketene Aminals with Racemic Allylic Alcohols

Organic Letters, Год журнала: 2024, Номер 26(2), С. 508 - 513

Опубликована: Янв. 5, 2024

The enantioselective allylic alkylation of nitro ketene aminals with racemic alcohols was realized by iridium/acid dual catalysis. An allyl group installed on the α-position in a branched-selective manner high efficiency excellent enantioselectivities (93–99% ee). protocol applied to late-stage modification neonicotinoid insecticides, which directly furnished novel analogue good insecticidal activity against Aphis craccivora (LC50 = 6.40 mg/L). On basis control experiment, an aza-ene-type reaction mechanism proposed.

Язык: Английский

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Zinc-Catalyzed Asymmetric Cascade Michael/Acyl Transfer Reaction between α-Hydroxy Aryl Ketones and Enynones

Organic Letters, Год журнала: 2023, Номер 25(11), С. 1918 - 1923

Опубликована: Март 16, 2023

We described herein a neoteric enantioselective cascade Michael/acyl transfer reaction of enynones and α-hydroxy aryl ketones catalyzed by dinuclear zinc cooperative catalysis. A series structurally diverse chiral 1,5-dicarbonyl compounds were synthesized in good yields with excellent stereoselectivities. This strategy features broad substrate scope, high atom economy, as well efficient electrophilic acyl reagents asymmetric reactions for the first time.

Язык: Английский

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Asymmetric Retro-Claisen Reaction Catalyzed by Chiral Aza-Bisoxazoline–Zn(II) Complex: Enantioselective Synthesis of α-Arylated Ketones

Organic Letters, Год журнала: 2023, Номер 25(10), С. 1706 - 1710

Опубликована: Март 7, 2023

An asymmetric retro-Claisen reaction of α-monosubstituted β-diketones and quinones (or quinone imine) has been developed under the catalysis a chiral aza-bisoxazoline–Zn(II) complex. The proceeds via sequence conjugate addition, arylation, hemiketal anion-initiated C–C bond cleavage, enantioselective protonation enolate to provide various functionalized α-arylated ketones bearing tertiary stereogenic center with high enantioselectivities. Notably, biologically important benzofuran γ-butyrolactone derivatives could be synthesized by application protocol.

Язык: Английский

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