Palladium-Catalyzed Ligand-Controlled Switchable Hetero-(5 + 3)/Enantioselective [2σ+2σ] Cycloadditions of Bicyclobutanes with Vinyl Oxiranes

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(29), С. 19621 - 19628

Опубликована: Май 13, 2024

For nearly 60 years, significant research efforts have been focused on developing strategies for the cycloaddition of bicyclobutanes (BCBs). However, higher-order and catalytic asymmetric BCBs long-standing formidable challenges. Here, we report Pd-catalyzed ligand-controlled, tunable cycloadditions divergent synthesis bridged bicyclic frameworks. The dppb ligand facilitates formal (5+3) vinyl oxiranes, yielding valuable eight-membered ethers with scaffolds in 100% regioselectivity. Cy-DPEphos promotes selective hetero-[2σ+2σ] to access pharmacologically important 2-oxabicyclo[3.1.1]heptane (O-BCHeps). Furthermore, corresponding O-BCHeps 94–99% ee has achieved using chiral (S)-DTBM-Segphos, representing first cross-dimerization two strained rings. obtained are promising bioisosteres ortho-substituted benzenes.

Язык: Английский

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Three-dimensional saturated C(sp3)-rich bioisosteres for benzene

Nature Reviews Chemistry, Год журнала: 2024, Номер 8(8), С. 605 - 627

Опубликована: Июль 9, 2024

Язык: Английский

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Synthesis of Azabicyclo[3.1.1]heptenes Enabled by Catalyst-Controlled Annulations of Bicyclo[1.1.0]butanes with Vinyl Azides

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(27), С. 18565 - 18575

Опубликована: Июнь 27, 2024

Bridged bicyclic scaffolds are emerging bioisosteres of planar aromatic rings under the concept "escape from flatland". However, adopting this into exploration pyridines remains elusive due to challenge incorporating a N atom such bridged structures. Herein, we report practical routes for divergent synthesis 2- and 3-azabicyclo[3.1.1]heptenes (aza-BCHepes) as potential readily accessible vinyl azides bicyclo[1.1.0]butanes (BCBs) via two distinct catalytic annulations. The reactivity tailored with BCBs is key achieving transformations. Ti

Язык: Английский

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Lewis Acid Catalyzed Cycloaddition of Bicyclobutanes with Ynamides for the Synthesis of Polysubstituted 2‐Amino‐bicyclo[2.1.1]hexenes

Angewandte Chemie International Edition, Год журнала: 2024, Номер 63(32)

Опубликована: Май 24, 2024

Abstract Synthesis of bicyclic scaffolds has gained significant attention in drug discovery due to their potential mimic benzene bioisosteres. Here, we present a mild and scalable Sc(OTf) 3 ‐catalyzed [3+2] cycloaddition bicyclo[1.1.0]butanes (BCBs) with ynamides, yielding diverse array polysubstituted 2‐amino‐bicyclo[2.1.1]hexenes good excellent yields. These products offer valuable starting materials for the construction novel functionalized bicyclo[1.1.0]butanes. Preliminary mechanistic studies indicate that reaction involves nucleophilic addition ynamides bicyclo[1.1.0]butanes, followed by an intramolecular cyclization situ generated enolate keteniminium ion. We expect these findings will encourage utilization complex bioisosteres foster further investigation into BCB‐based chemistry.

Язык: Английский

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B(C₆F₅)₃-Catalyzed Formal (n + 3) (n = 5 and 6) Cycloaddition of Bicyclo[1.1.0]butanes to Medium Bicyclo[n.1.1]alkanes

Organic Letters, Год журнала: 2024, Номер 26(19), С. 4104 - 4110

Опубликована: Май 3, 2024

Herein, a B(C6F5)3-catalyzed formal (n + 3) = 5 and 6) cycloaddition of bicyclo[1.1.0]butanes (BCBs) with imidazolidines/hexahydropyrimidines is described. The reaction provides modular, atom-economical, efficient strategy to two libraries synthetically challenging medium-bridged rings, 2,5-diazabicyclo[5.1.1]nonanes 2,6-diazabicyclo[6.1.1]decanes, in moderate excellent yields. This also features simple operation, mild conditions, broad substrate scope. A scale-up experiment various synthetic transformations products further highlight the utility.

Язык: Английский

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Lewis acid catalyzed [4+2] annulation of bicyclobutanes with dienol ethers for the synthesis of bicyclo[4.1.1]octanes

Chemical Science, Год журнала: 2024, Номер 15(28), С. 10823 - 10829

Опубликована: Янв. 1, 2024

Bicyclo[4.1.1]octanes (BCOs) were synthesized in up to quantitative yields through the formal [4+2] cycloaddition of aryl and alkyl bicyclobutane (BCB) ketones with dienol silyl ethers using Al(OTf) 3 as a Lewis acid catalyst.

Язык: Английский

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Palladium-catalyzed decarboxylative (4 + 3) cycloadditions of bicyclobutanes with 2-alkylidenetrimethylene carbonates for the synthesis of 2-oxabicyclo[4.1.1]octanes

Chemical Science, Год журнала: 2024, Номер 15(34), С. 13942 - 13948

Опубликована: Янв. 1, 2024

While cycloaddition reactions of bicyclobutanes (BCBs) have emerged as a potent method for synthesizing (hetero-)bicyclo[

Язык: Английский

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Enantioselective formal (3 + 3) cycloaddition of bicyclobutanes with nitrones enabled by asymmetric Lewis acid catalysis

Nature Communications, Год журнала: 2024, Номер 15(1)

Опубликована: Сен. 12, 2024

Язык: Английский

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Copper-Catalyzed Enantioselective [4π + 2σ] Cycloaddition of Bicyclobutanes with Nitrones

Journal of the American Chemical Society, Год журнала: 2024, Номер unknown

Опубликована: Сен. 25, 2024

The selective construction of bridged bicyclic scaffolds has garnered increasing attention because their extensive use as saturated bioisosteres arene in pharmaceutical industry. However, sharp contrast to racemic counterparts, assembling chiral structures an enantioselective and regioselective manner remains challenging. Herein, we describe our protocol for constructing 2-oxa-3-azabicyclo[3.1.1]heptanes (BCHeps) by [4π + 2σ] cycloadditions bicyclo[1.1.0]butanes (BCBs) nitrones taking advantage a copper(II) complex Lewis acid catalyst. This method features mild conditions, good functional group tolerance, high yield (up 99%), excellent enantioselectivity 99% ee). Density theory (DFT) calculation elucidates the origin reaction's mechanism BCB activation Cu(II) complex.

Язык: Английский

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Facile access to bicyclo[2.1.1]hexanes by Lewis acid-catalyzed formal cycloaddition between silyl enol ethers and bicyclo[1.1.0]butanes

Nature Communications, Год журнала: 2024, Номер 15(1)

Опубликована: Июль 20, 2024

Abstract Saturated three-dimensional carbocycles have gained increasing prominence in synthetic and medicinal chemistry. In particular, bicyclo[2.1.1]hexanes (BCHs) been identified as the molecular replacement for benzenes. Here, we present facile access to a variety of BCHs via stepwise two-electron formal (3 + 2) cycloaddition between silyl enol ethers bicyclo[1.1.0]butanes (BCBs) under Lewis acid catalysis. The reaction features wide functional group tolerance ethers, allowing efficient construction two vicinal quaternary carbon centers silyl-protected tertiary alcohol unit streamlined fashion. Interestingly, with conjugated dienol can provide bicyclo[4.1.1]octanes (BCOs) equipped that facilitate further transformation. utilities this methodology are demonstrated by late-stage modification natural products, transformations units on bicyclo[2.1.1]hexane frameworks, derivatization bicyclo[4.1.1]octanes, delivering functionalized bicycles traditionally inaccessible.

Язык: Английский

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