2,2’‐Biquinoline‐Based Recyclable Electroauxiliaries for the Generation of Alkyl Radicals via C−C Bond Cleavage DOI Creative Commons
Shahilan Ratnam,

Shreya Unone,

Daniel Janßen-Müller

et al.

Chemistry - A European Journal, Journal Year: 2023, Volume and Issue: 29(50)

Published: June 2, 2023

Alkyl radical precursors are essential for a wide variety of photocatalytic and 3d-metal-catalyzed C-C bond forming reactions. Neutral organic heterocycles as electroauxiliaries such 4-alkyl Hantzsch esters have become reliable tools alkyl formation. Here we show that 2,2'-biquinoline-derived alkyl-substituted dihydroquinolines act competent with the ability to form primary, secondary tertiary radicals. Hydroalkylation benzalmalononitriles N-Boc protected diazenes has been achieved through copper catalysis under mild conditions 50 °C good very yields up 85 %. Furthermore, dihydroquinolines' reactivity towards denitrative alkylation nitroolefins β-nitrostyrene was discovered. Most importantly, released biquinoline can be recycled, which greatly improves overall atom-economy these in comparison previous N-heterocyclic electroauxiliaries.

Language: Английский

Construction of C−S and C−Se Bonds from Unstrained Ketone Precursors under Photoredox Catalysis DOI Creative Commons
Hao Wu, Shuguang Chen,

Chunni Liu

et al.

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(8)

Published: Jan. 8, 2024

A mild photoredox catalyzed construction of sulfides, disulfides, selenides, sulfoxides and sulfones from unstrained ketone precursors is introduced. Combination this deacylative process with S

Language: Английский

Citations

24
Aromatization-driven deconstructive functionalization of spiro dihydroquinazolinones via dual photoredox/nickel catalysis DOI Creative Commons

Hong-Jie Miao,

Jinhua Zhang, Wenke Li

et al.

Chemical Science, Journal Year: 2024, Volume and Issue: 15(23), P. 8993 - 8999

Published: Jan. 1, 2024

The aromatization-driven deconstructive coupling of spiro carbocycles with organic halides via dual photoredox/nickel catalysis is developed. An in-depth mechanism study revealed that this reaction proceeded a radical-metal crossover pathway.

Language: Английский

Citations

20
Molecular Editing of Ketones through N-Heterocyclic Carbene and Photo Dual Catalysis DOI
Qing‐Zhu Li,

Mei-Hao He,

Rong Zeng

et al.

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(32), P. 22829 - 22839

Published: Aug. 1, 2024

The molecular editing of ketones represents an appealing strategy due to its ability maximize the structural diversity ketone compounds in a straightforward manner. However, developing efficient methods for arbitrary modification ketonic molecules, particularly those integrated within complex skeletons, remains significant challenge. Herein, we present unique recasting that involves radical acylation

Language: Английский

Citations

19
Copper‐Catalyzed C(sp3)‐Amination of Ketone‐Derived Dihydroquinazolinones by Aromatization‐Driven C−C Bond Scission DOI Creative Commons
Xin‐Yang Lv, Roman Abrams, Rubén Martı́n

et al.

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 62(8)

Published: Dec. 28, 2022

Herein, we describe the development of a copper-catalyzed C(sp3 )-amination proaromatic dihydroquinazolinones derived from ketones. The reaction is enabled by intermediacy open-shell species arising homolytic C-C bond-cleavage driven aromatization. protocol characterized its operational simplicity and generality, including chemical diversification advanced intermediates.

Language: Английский

Citations

47
Visible-Light-Photocatalyzed Dicarbofunctionalization of Conjugated Alkenes with Ketone-Based Dihydroquinazolinones DOI
Pinku Prasad Mondal, Subham Das,

Sreelakshmi Venugopalan

et al.

Organic Letters, Journal Year: 2023, Volume and Issue: 25(9), P. 1441 - 1446

Published: Feb. 23, 2023

A visible-light-photocatalyzed 1,2-arylalkylation of N-(arylsulfonyl)acrylamides with ketone-based dihydroquinazolinones is described. The formal C-C bond cleavage aliphatic ketones unified tandem radical alkylation/1,4-aryl migration/desulfonylation to forge two different types vicinal bonds and construct an all-carbon quaternary α-stereocenter, thus enhancing the carbogenic complexity tolerating diverse functionalities. Additional telescopic synthesis product diversification, this method features a dicarbofunctionalization conjugated nucleophilic alkyl precursor (dihydroquinazolinone) utilizing oxygen as green oxidant at ambient temperature.

Language: Английский

Citations

28
Deacylative arylation and alkynylation of unstrained ketones DOI Creative Commons
B. L. Zhang,

Hui Bai,

Bei‐Bei Zhan

et al.

Science Advances, Journal Year: 2024, Volume and Issue: 10(17)

Published: April 26, 2024

Ketones are ubiquitous in bioactive natural products, pharmaceuticals, chemical feedstocks, and synthetic intermediates. Hence, deacylative coupling reactions enable the versatile elaboration of a plethora chemicals to access complex drug candidates products. Here, we present arylation alkynylation strategies for synthesis wide range alkyl-tethered arenes alkynes from cyclic ketones methyl under dual nickel/photoredox catalysis. This reaction begins by generating pre-aromatic intermediate (PAI) through condensation ketone

Language: Английский

Citations

11
Photocatalytic C–C bond thio(seleno)esterification of 1,2-diketone-derived pro-aromatic intermediates DOI Creative Commons
Amit Pal, Soumya Sarkar,

Aaron Shibu

et al.

Chemical Communications, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 1, 2025

We report an organophotocatalyst-enabled oxidant-free C–S/C–Se bond coupling of (un)symmetrical 1,2-diketones via pro-aromatic dihydroquinazolinones/benzothiazolines, employing readily accessible disulfides/diselenides.

Language: Английский

Citations

2
Methyl Ketones as Alkyl Halide Surrogates: A Deacylative Halogenation Approach for Strategic Functional Group Conversions DOI
Zining Zhang,

Qi Zhu,

Daniel Pyle

et al.

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(38), P. 21096 - 21103

Published: Sept. 15, 2023

Alkyl halides are versatile precursors to access diverse functional groups (FGs). Due their lability, the development of surrogates for alkyl is strategically important complex molecule synthesis. Given stability and ease derivatization inherent in common ketones, here we report a deacylative halogenation approach convert various methyl ketones corresponding chlorides, bromides, iodides. The reaction driven by forming an aromatic byproduct, i.e., 1,2,4-triazole, which N′-methylpicolinohydrazonamide (MPHA) employed form prearomatic intermediate halogen atom-transfer (XAT) reagents used quench radical intermediate. efficient yielding primary secondary from wide range with broad FG tolerance. It also works natural-product-derived fluoro-containing substrates. In addition, one-pot conversions other FGs annulations alkenes alkynes through realized. Moreover, unusual iterative homologation iodides demonstrated. Finally, mechanistic studies reveal intriguing double XAT process iodination reaction, could have implications beyond this work.

Language: Английский

Citations

18
Photocatalytic C–C Bond Azidation and Cyanation of Acyclic Ketones via a Pro-aromatic Intermediate DOI
Sandip Bag,

Amit Dhibar,

Shruti Moorthy

et al.

Organic Letters, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 10, 2025

Herein, we report a formal C–C bond azidation and cyanation of unactivated aliphatic ketones using commercially available tosyl azide cyanide, respectively. A visible-light-mediated organophotocatalyst enables radical ketone-derived pro-aromatic dihydroquinazolinones (under mostly redox-neutral conditions) as supported by preliminary mechanistic studies. These metal-free scalable protocols can be used to synthesize tertiary, secondary, primary alkyl azides nitriles with good functional group tolerance postsynthetic diversification the group, including bioconjugation.

Language: Английский

Citations

1
Photocatalytic Alkylation/Arylative Cyclization of N-Acrylamides of N-Heteroarenes and Arylamines with Dihydroquinazolinones from Unactivated Ketones DOI
Sandip Bag, Shubham Ojha,

Sreelakshmi Venugopalan

et al.

The Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 88(16), P. 12121 - 12130

Published: July 29, 2023

We describe a visible-light photoredox-catalyzed alkylation/arylative cyclization of N-acrylamides─from 2-arylindoles, 2-arylbenzimidazoles, or N-substituted anilines─with ketone-derived dihydroquinazolinones, accessing indolo- and benzimidazolo[2,1-a]isoquinolines 2-oxindoles. The consecutive incorporation alkyl- aryl-carbogenic motifs across C=C bond via formal cleavage ketone α-C-C arene C-H bonds leads to the formation five- six-membered rings, with an all-carbon quaternary stereocenter. This dicarbofunctionalization elaborates aromatization-driven radical C-C functionalization unactivated aliphatic ketones construct diverse cyclic structures functionality tolerance.

Language: Английский

Citations

17