Switchable Divergent Synthesis Using Photocatalysis

ACS Catalysis, Journal Year: 2022, Volume and Issue: 12(3), P. 1857 - 1878

Published: Jan. 20, 2022

A highly selective and divergent synthesis enables access to various molecules has garnered broad interest from not only organic chemists but also medicinal biologists who work with chemical libraries. Since the 20th century, such transformations have been achieved using transition-metal-catalyzed reactions, in which choice of catalyst or ligand crucially affects selectivity. Over past several decades, photocatalysts attracted a considerable amount attention because they provide additional ways control reaction intermediates product selectivity via electron energy transfer. From this perspective, we highlight recent development switchable syntheses photocatalysts, are difficult achieve classical catalytic transformations.

Language: Английский

---

Enantioselective desymmetrization reactions in asymmetric catalysis

Tetrahedron, Journal Year: 2022, Volume and Issue: 106-107, P. 132629 - 132629

Published: Jan. 1, 2022

Language: Английский

---

Visible‐Light‐Promoted Switchable Selective Oxidations of Styrene Over Covalent Triazine Frameworks in Water

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(15)

Published: Jan. 28, 2023

Using photocatalytic oxidation to convert basic chemicals into high value compounds in environmentally benign reaction media is a current focus catalytic research. The challenge lies gaining controllability over product formation selectivity. We design covalent triazine frameworks as heterogeneous, metal-free, and recyclable photocatalysts for visible-light-driven switchable selective of styrene pure water. Selectivity was achieved by activation or deactivation the specific photogenerated oxygen species. same photocatalyst, H2 O2 , benzaldehyde obtained with 99 % conversion selectivity single product. highly challenging sensitive epoxidation carried out creating peroxymonocarbonate an initial agent presence bicarbonate, which led oxide up 76 near quantitative conversion. This study demonstrates preliminary yet interesting example simple control reactions organic

Language: Английский

---

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

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(29), P. 19621 - 19628

Published: May 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.

Language: Английский

---

Switching between the [2π+2σ] and Hetero‐[4π+2σ] Cycloaddition Reactivity of Bicyclobutanes with Lewis Acid Catalysts Enables the Synthesis of Spirocycles and Bridged Heterocycles

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(29)

Published: May 11, 2024

Abstract The exploration of the complex chemical diversity bicyclo[n.1.1]alkanes and their use as benzene bioisosteres has garnered significant attention over past two decades. Regiodivergent syntheses thiabicyclo[4.1.1]octanes (S‐BCOs) highly substituted bicyclo[2.1.1]hexanes (BCHs) using a Lewis acid‐catalyzed formal cycloaddition bicyclobutanes (BCBs) 3‐benzylideneindoline‐2‐thione derivatives have been established. first hetero‐(4+3) BCBs, catalyzed by Zn(OTf) 2 , was achieved with broad substrate scope under mild conditions. In contrast, less electrophilic BCB ester undergoes Sc(OTf) 3 ‐catalyzed [2π+2σ] reaction 1,1,2‐trisubstituted alkenes, yielding BCHs spirocyclic quaternary carbon center. Control experiments preliminary theoretical calculations suggest that diastereoselective product formation may involve concerted between zwitterionic intermediate E ‐1,1,2‐trisubstituted alkenes. Additionally, nucleophilic ring‐opening mechanism.

Language: Английский

---

Divergent Synthesis of Fluoroalkyl Ketones through Controlling the Reactivity of Organoboronate Complexes

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(6), P. 4026 - 4035

Published: Feb. 1, 2024

Herein, we report a divergent synthesis of fluoroalkyl ketones through visible-light-induced reactions between readily available organoboronic esters and acylsilanes. Selective control the reactivity in situ generated organoboronate complexes is key to achieving transformations. Under basic conditions, undergo deboronative fluoride elimination, resulting formation enol silyl ethers as intermediates that react with various electrophiles generate defluorinated products. Moreover, combination peroxide, 1,2-shift group favored over elimination ketal intermediates, leading This transition-metal-free reaction operationally simple, aryl, alkenyl, alkyl boronic are all suitable substrates. The synthetic potential has been demonstrated by gram-scale facile bioactive molecules including zifrosilone its analogs.

Language: Английский

---

Switchable divergent di- or tricarboxylation of allylic alcohols with CO2

Chem, Journal Year: 2024, Volume and Issue: 10(3), P. 938 - 951

Published: Jan. 10, 2024

Language: Английский

---

Visible-Light-Induced Chemodivergent Synthesis of Tetracyclic Quinazolinones and 3-Iminoisoindoliones via the Substrate Control Strategy

The Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 89(7), P. 4395 - 4405

Published: March 19, 2024

A visible-light-induced chemodivergent synthesis of tetracyclic quinazolinones and 3-iminoisoindoliones has been developed. This reaction afforded two kinds different products by substrate control. detailed investigation the mechanism revealed that this consecutive photoinduced electron transfer (ConPET) cascade cyclization involved a radical process, aryl was crucial intermediate. method employed 4-DPAIPN as photocatalyst i-Pr2NEt sacrificial donor leading to metal-free conditions.

Language: Английский

---

Ni-catalyzed ligand-controlled divergent and selective synthesis

Science China Chemistry, Journal Year: 2023, Volume and Issue: 66(11), P. 2951 - 2976

Published: May 5, 2023

Language: Английский

---

Enantioselective Chemodivergent Three-Component Radical Tandem Reactions through Asymmetric Photoredox Catalysis

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(36), P. 20141 - 20148

Published: Aug. 28, 2023

Chemodivergent synthesis has been achieved in asymmetric photocatalysis. Under a dual catalyst system consisting of chiral phosphoric acid and DPZ as photosensitizer, different inorganic bases enabled the formation two sets valuable products from three-component radical tandem transformations 2-bromo-1-arylenthan-1-ones, styrenes, quinoxalin-2(1H)-ones. The key to success was distinct pKa environment, which radicals that formed on quinoxalin-2(1H)-one rings after addition processes underwent either single-electron oxidation or reduction. In addition, this work represents first use quinoxalin-2(1H)-ones photoredox catalysis.

Language: Английский

---