Photoisomerization of “Partially Embedded Dihydropyridazine” with a Helical Structure DOI Open Access
Kazuteru Usui,

Ami Amano,

Kasumi Murayama

et al.

Chemistry - A European Journal, Journal Year: 2023, Volume and Issue: 29(62)

Published: Aug. 24, 2023

Herein, we report the synthesis of two "partially embedded fused-dihydropyridazine N-aryl aza[5]helicene derivatives" (PDHs) and demonstration their intrinsic photo-triggered multi-functional properties based on a Kekulé biradical structure. Introducing bulky electron-withdrawing trifluoromethyl or pentafluoroethyl groups into framework (PDH-CF3 -C2 F5 ) gives PDH axial chirality helicity P M forms, even at room temperature. Upon photo-irradiation PDH-CF3 in frozen solution, an ESR signal from triplet with zero-field splitting values, generated by N-N bond dissociation, was observed. However, when irradiation turned off, became silent, thus indicating existence equilibria: between quinoidal forms structure, cleavage recombination. The observed photo- thermally induced behaviors indicate that T-type photochromic molecules are involved photoisomerization mechanism involving equilibria. Inspired photoisomerization, control photoracemization achieved. Multiple functionalities, such as photochromism, photo-excitation-mediated formation, photoracemization, which attributed to dihydropyridazine" demonstrated.

Language: Английский

Iron-catalysed stereoselective NH transfer enables dynamic kinetic resolution of sulfoxides DOI Creative Commons

Fang-Xu Fan,

Hui Xu,

Sheng Tang

et al.

Nature Communications, Journal Year: 2025, Volume and Issue: 16(1)

Published: Feb. 8, 2025

Transition metal-catalysed asymmetric nitrene transfer provides a powerful means to access various bioactive N-containing compounds as single enantiomers. However, enantioselective NH that allows concise assembly of unprotected enantioenriched amines remains an enduring challenge. We report here iron-catalysed stereoselective imidation sulfoxide, which is integrated with photocatalytic racemisation enabling dynamic kinetic resolution (DKR) strategy for direct and synthesis NH-sulfoximines. This approach distinct from the existing methods by avoiding protecting group manipulations and/or use chiral substrates. Computational studies on reaction suggest involvement iron-aminyl radical intermediate, its sulfoxide proceeds through synchronous nucleophilic addition nitrogen center ligand-to-metal electron process form N–S bond. In addition, stereoselectivity primarily dictated difference in dispersion interactions transition states. Enantioselective Here, authors

Language: Английский

Citations

0
Photocatalytic deracemisation of cobalt(iii) complexes with fourfold stereogenicity DOI Creative Commons

Tanno A. Schmidt,

Christof Sparr

Chemical Communications, Journal Year: 2022, Volume and Issue: 58(87), P. 12172 - 12175

Published: Jan. 1, 2022

The deracemisation of fourfold stereogenic cobalt( iii ) diketonates with a chiral photocatalyst is described.

Language: Английский

Citations

10
Synthesis of Chiral Sulfoxides by A Cyclic Oxidation‐Reduction Multi‐Enzymatic Cascade Biocatalysis DOI
Jin Tian,

Shihuan Zhou,

Yanli Chen

et al.

Chemistry - A European Journal, Journal Year: 2024, Volume and Issue: 30(19)

Published: Jan. 30, 2024

Optically pure sulfoxides are valuable organosulfur compounds extensively employed in medicinal and organic synthesis. In this study, we present a biocatalytic oxidation-reduction cascade system designed for the preparation of enantiopure sulfoxides. The involves cooperation low-enantioselective chimeric oxidase SMO (styrene monooxygenase) with high-enantioselective reductase MsrA (methionine sulfoxide A), facilitating "non-selective oxidation selective reduction" cycles prochiral sulfide oxidation. regeneration requisite cofactors was achieved via catalysis process involving three auxiliary enzymes, sustained by cost-effective D-glucose. Under optimal reaction conditions, series heteroaryl alkyl, aryl alkyl dialkyl R configuration were synthesized through "one-pot, one step" reaction. obtained exhibited high yields >90 % demonstrated enantiomeric excess (ee) values exceeding 90 %. This study represents an unconventional efficient way utilizing synthesis

Language: Английский

Citations

1
Photo Energy Transfer-Enabled Thiosulfinylation of Alkynes for Asymmetric Synthesis of Sultims DOI
Zhiming Zhu,

Yuanyuan Zhao,

Ziyang Li

et al.

Organic Letters, Journal Year: 2024, Volume and Issue: unknown

Published: Nov. 25, 2024

An asymmetric and highly practical thiosulfinylation of alkynes is established for the synthesis sultim derivatives. The disclosed platform featured broad substrate scope group tolerance diverse biologically important molecules under mild operationally simple conditions. Notably, obtained chiral sulfinyl derivatives have demonstrated their potential application in further gram-scale product derivatizations, providing a chance drug discovery.

Language: Английский

Citations

1
Conversion of Racemic Alkyl Aryl Sulfoxides into Pure Enantiomers Using a Recycle Photoreactor: Tandem Use of Chromatography on Chiral Support and Photoracemization on Solid Support DOI Creative Commons

Kumi Tozawa,

Kosho Makino, Yuki Tanaka

et al.

The Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 88(11), P. 6955 - 6961

Published: May 8, 2023

Chiral sulfoxides are valuable in the fields of medicinal chemistry and organic synthesis. A recycle photoreactor utilizing concept deracemization, where a racemate is converted into pure enantiomer, developed successfully applied syntheses chiral alkyl aryl sulfoxides. The recycling system consists rapid photoracemization using an immobilized photosensitizer separation enantiomers via high-performance liquid chromatography, desired obtained after 4-6 cycles. key to success site, wherein 2,4,6-triphenylpyrylium on resin irradiated (405 nm) enable photoracemizations As green requires no components, it should be useful alternative for application producing compounds.

Language: Английский

Citations

3
Isomerization of E-Cinnamamides into Z-Cinnamamides Using a Recycling Photoreactor DOI Creative Commons

Mayuko Suga,

Saki Fukushima,

Kosho Makino

et al.

The Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 89(12), P. 8836 - 8844

Published: June 5, 2024

The photocatalytic synthesis of thermodynamically less-stable Z-alkenes has received considerable research attention in recent years. In this study, a recycling photoreactor was applied to the photoisomerization E-alkenes (cinnamamide and Weinreb amide derivatives) produce Z-alkenes. closed-loop system comprises an immobilized photosensitizer achieve rapid high-performance liquid chromatography instrument for separation Z/E diastereomers. After 4–10 cycles, desired pure were obtained efficiently. system, (thioxanthone) covalently on silica gel via bonding, which led enhanced activity compared parent thioxanthone. This shows promise as alternative production

Language: Английский

Citations

0
Photoisomerization of “Partially Embedded Dihydropyridazine” with a Helical Structure DOI Open Access
Kazuteru Usui,

Ami Amano,

Kasumi Murayama

et al.

Chemistry - A European Journal, Journal Year: 2023, Volume and Issue: 29(62)

Published: Aug. 24, 2023

Herein, we report the synthesis of two "partially embedded fused-dihydropyridazine N-aryl aza[5]helicene derivatives" (PDHs) and demonstration their intrinsic photo-triggered multi-functional properties based on a Kekulé biradical structure. Introducing bulky electron-withdrawing trifluoromethyl or pentafluoroethyl groups into framework (PDH-CF3 -C2 F5 ) gives PDH axial chirality helicity P M forms, even at room temperature. Upon photo-irradiation PDH-CF3 in frozen solution, an ESR signal from triplet with zero-field splitting values, generated by N-N bond dissociation, was observed. However, when irradiation turned off, became silent, thus indicating existence equilibria: between quinoidal forms structure, cleavage recombination. The observed photo- thermally induced behaviors indicate that T-type photochromic molecules are involved photoisomerization mechanism involving equilibria. Inspired photoisomerization, control photoracemization achieved. Multiple functionalities, such as photochromism, photo-excitation-mediated formation, photoracemization, which attributed to dihydropyridazine" demonstrated.

Language: Английский

Citations

0