Photocatalytic Synthesis of Polycyclic Indolones

Saget, Tanguy; König, Burkhard

doi:10.1002/chem.202001324

Cited by 36 publications

(8 citation statements)

References 56 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The data that supports the findngs of this study including characterization data and NMR spectra for all compounds are available in the supplemental material of this article. The authors have cited additional references within the supplemental material [24–59] …”

Section: Data Available Statementmentioning

confidence: 99%

Redox‐Neutral Multicatalytic Cerium Photoredox‐Enabled Cleavage of O−H Bearing Substrates

Morris,

Barriault

2024

Chemistry A European J

View full text Add to dashboard Cite

The need for synthetic methodologies capable of rapidly altering molecular structure are in high demand. Most existing methods to modify scaffolds rely on net exothermicity to drive the desired transformation. We sought to develop a general strategy for the cleavage of C–C bonds b to hydroxyl groups independent of inherent substrate strain. To this end we have applied a multicatalytic cerium photoredox‐based system capable of activating O–H bonds in lactols to deliver formate esters. The same system is also capable of effecting hydrodecarboxylation and hydrodecarbonylation reactions. Initial mechanistic probes demonstrate atomic chlorine (Cl•) is generated under the reaction conditions, but substrate activation through cerium‐alkoxides or ‐carboxylates cannot be ruled out.

show abstract

Section: Data Available Statementmentioning

confidence: 99%

Redox‐Neutral Multicatalytic Cerium Photoredox‐Enabled Cleavage of O−H Bearing Substrates

Morris,

Barriault

2024

Chemistry A European J

View full text Add to dashboard Cite

show abstract

“…In the recent past, König and Saget reported a photoredox-catalyzed de novo synthesis of polycyclic indolones 112 through decarboxylative intramolecular annulation employing RAEs of 111 (Scheme ). Starting from readily available indoles 111 , the corresponding NHPI esters were synthesized in situ and exposed to visible light in the presence of Ir(ppy) 3 as the photocatalyst. The alkyl radical generated after decarboxylation undergoes intramolecular cyclization, followed by SET oxidation and re-aromatization, leading to polycyclic indolones 112 in moderate to good yields.…”

Section: C–c Bond Formationmentioning

confidence: 99%

Single Electron Transfer-Induced Redox Processes Involving N-(Acyloxy)phthalimides

et al. 2021

View full text Add to dashboard Cite

The past decade has witnessed the emergence of N-(acyloxy)phthalimides (NHPI esters) and its derivatives at the forefront of synthetic methods facilitating the construction of diverse molecular frameworks from the readily available carboxylic acid feedstock. The NHPI esters are predisposed to undergo reductive fragmentation via a single electron transfer (SET) process under thermal, photochemical, or electrochemical conditions to generate the corresponding carbon-or nitrogencentered radicals that participate in a multitude of synthetic transformations to forge carbon−carbon and carbon−heteroatom bonds. The chemistry involving NHPI esters has received broad applicability not only in well-designed cascade annulations but also in medicinal chemistry and natural product synthesis. This comprehensive Review, broadly categorized according to the nature of the bond formation, details the progress made in this field since the initial discovery by providing representative examples with mechanistic details, with an emphasis on challenges and future directions.

show abstract

“…Encouraged by these results, the two-phase annulation strategy was further applied to the late-stage construction of complex N-heteroarene-based polycyclic compounds (Fig. 4C) 19 . This process requires consecutive and orthogonal N─H and C─H alkylations in the presence of multiple FGs including olefins, nitriles, electron-rich arenes, and reactive carbonyls, which are hard to be all tolerated under strongly Lewis acidic, oxidative, or reductive conditions.…”

Section: Synthetic Utilitymentioning

confidence: 99%

“…1B) [5][6][7][8] . However, a long-standing challenge of this strategy arises from limited choices of reactive moieties at the alkyl terminus, regardless through either a polar-or radicaladdition pathway [9][10][11][12][13][14][15][16][17][18][19][20] . The typical alkylative annulation relies on the use of special or very reactive coupling partners, such as alkyl halides 9-13 , xanthates 14,15 , phenyl selenides 16 , allyl sulfones 17 , redox-active esters 18,19 , etc.…”

mentioning

confidence: 99%

Deacylation-aided C–H alkylative annulation through C–C cleavage of unstrained ketones

Zhou

Dong

2021

Nat Catal

View full text Add to dashboard Cite

Arene-and heteroarene-fused rings are pervasive in biologically active molecules. Direct annulation between a C─H bond on the aromatic core and a tethered alkyl moiety provides a straightforward approach to access these scaffolds; however, such a strategy is often hampered by the need of special reactive groups and/or less compatible cyclization conditions. It would be synthetically appealing if a common native functional group can be used as a handle to enable a general C─H annulation with diverse aromatic rings. Here, we show a deacylative annulation strategy for preparing a large variety of aromatic-fused rings from linear simple ketone precursors. The reaction starts with homolytic cleavage of the ketone α C─C bond via a pre-aromatic intermediate, followed by a radical-mediated dehydrogenative cyclization. Using widely available ketones as the robust radical precursors, this deconstructive approach allows streamlined assembly of complex polycyclic structures with broad functional group tolerance.Arenes and heteroarene-fused rings are commonly found in structures of drugs, natural products, and other bioactive compounds (Fig. 1A). 1-4 Among many possible synthetic approaches, the direct intramolecular C─H alkylation of the aromatic core from a linear precursor, namely C─H alkylative annulation, provides a straightforward approach to access these fused scaffolds, as pre-functionalization of arenes could be avoided (Fig. 1B) [5][6][7][8] . However, a long-standing challenge of this strategy arises from limited choices of reactive moieties at the alkyl terminus, regardless through either a polar-or radicaladdition pathway [9][10][11][12][13][14][15][16][17][18][19][20] . The typical alkylative annulation relies on the use of special or very reactive coupling partners, such as alkyl halides 9-13 , xanthates 14,15 , phenyl selenides 16 , allyl sulfones 17 , redox-active esters 18,19 , etc.; it is generally not a trivial task to introduce these high-energy functional groups (FGs) with tolerating existing FGs 21,22 . In addition, carrying out multi-step operations with these sensitive FGs could also be difficult, which hinders implementation of convergent synthetic approaches. Hence, from the viewpoint of synthetic *

show abstract

Photocatalytic Synthesis of Polycyclic Indolones

Abstract: Scheme3.Scope of the reaction.Scheme4.Gram-scale reaction and synthetic applications.Scheme5.Synthesis of azepinoindolones.

Cited by 36 publications

References 56 publications

Redox‐Neutral Multicatalytic Cerium Photoredox‐Enabled Cleavage of O−H Bearing Substrates

Redox‐Neutral Multicatalytic Cerium Photoredox‐Enabled Cleavage of O−H Bearing Substrates

Single Electron Transfer-Induced Redox Processes Involving N-(Acyloxy)phthalimides

Deacylation-aided C–H alkylative annulation through C–C cleavage of unstrained ketones

Contact Info

Product

Resources

About