C–H activation-initiated spiroannulation reactions and their applications in the synthesis of spirocyclic compounds

Organic & Biomolecular Chemistry, Journal Year: 2024, Volume and Issue: 22(12), P. 2324 - 2338

Published: Jan. 1, 2024

This review summarizes the most recent progress made in C–H bond activation-initiated spiroannulation reactions and their applications construction of structurally diverse biologically valuable spirocyclic scaffolds.

Language: Английский

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Rhodium(iii)-catalyzed intermolecular [3+3] annulation of benzoxazines with quinone compounds: access to spiro-heterocyclic scaffolds

Chemical Communications, Journal Year: 2023, Volume and Issue: 59(77), P. 11520 - 11523

Published: Jan. 1, 2023

A rhodium(III)-catalyzed redox-neutral spiroannulation approach to access the spiro[benzo[b][1,4]oxazine-benzo[c]chromene skeleton is described in this contribution. variety of spiro[5.5]-heterocyclic scaffolds were obtained moderate excellent yields under mild conditions. Key features protocol are good substrate scope, silver-free conditions, low catalyst loadings, easy handling air and 100% atom economy. Furthermore, scale-up reactions late-stage derivatizations highlight potential synthetic utility methodology.

Language: Английский

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Transition Metal‐Catalyzed Transformations of Chalcones

The Chemical Record, Journal Year: 2024, Volume and Issue: 24(8)

Published: July 15, 2024

Chalcones are a class of naturally occurring flavonoid compounds associated to variety biological and pharmacological properties. Several reviews have been published describing the synthesis properties vast array analogues. However, overviews on reactivity chalcones has only explored in few accounts. To fill this gap, systematic survey most recent developments transition metal-catalyzed transformation was performed. The chemistry copper, palladium, zinc, iron, manganese, nickel, ruthenium, cobalt, rhodium, iridium, silver, indium, gold, titanium, platinum, among others, as versatile catalysts will be highlighted, covering literature from year 2000 2023, more than 380 publications.

Language: Английский

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Substrate‐Controlled Product Divergence in Iron(III)‐Catalyzed Reactions of Propargylic Alcohols: Easy Access to Spiro‐indenyl 1,4‐Benzoxazines and 2‐(2,2‐Diarylvinyl)quinoxalines

Chemistry - A European Journal, Journal Year: 2023, Volume and Issue: 29(13)

Published: Jan. 18, 2023

We report herein unprecedented cascade reactions of O-propargyl-N-tosyl-amino phenols with 10 mol% FeCl3 in DCE at room temperature for 0.67-3 h to form spiro-indenyl 1,4-benzoxazines 38-89 % yield. Replacing the substrates' oxygen atom by a N-tosylimine group followed treatment same catalyst and solvent 80 °C produced 2-(2,2-diarylvinyl)quinoxalines 12-20 up 62 Mechanistic understanding provided an insight into transformations. The use simple substrates environmentally benign low-cost catalyst, broad substrate scope tolerance diverse functional groups makes methodology inherently attractive.

Language: Английский

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Synthesis of spiropyrans via Ru(ii)-catalyzed coupling of 3-aryl-2H-benzo[b][1,4]oxazines with benzoquinones

Organic & Biomolecular Chemistry, Journal Year: 2023, Volume and Issue: 22(5), P. 998 - 1009

Published: Dec. 26, 2023

An efficient Ru( ii )-catalyzed C–H activation-based spiroannulation of benzoxazines with easily available benzoquinone and N -sulfonyl quinone monoimine has been realized, providing a straightforward strategy to access NH-containing spiropyrans.

Language: Английский

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Diastereoselective Intramolecular Spirocyclization via C(sp3)‐H Bond Functionalization Towards the Synthesis of 2,7‐Diazaspiro[4.5]decane‐1,3‐diones

Advanced Synthesis & Catalysis, Journal Year: 2024, Volume and Issue: unknown

Published: Oct. 29, 2024

Abstract The C( sp 3 )−H functionalization via intramolecular hydride transfer initiated cascade annulation for the synthesis of spiro‐fused succinimide‐containing tetrahydroquinolines induced by iminium intermediates is described. A series diastereoselective 2,7‐diazaspiro[4.5]decanes‐1,3‐diones were achieved using ortho ‐amino‐benzylidene‐succinimide Lewis acid catalysis. This scandium triflate Sc(OTf) catalysed, oxidant‐free protocol leads to a class derivatives with 48–98% yield in single step.

Language: Английский

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Synergistic [4 + 1] Spiroannulation and Selective Ring-Opening Strategy toward γ-Spirolactams

Organic Letters, Journal Year: 2024, Volume and Issue: 26(46), P. 9859 - 9864

Published: Nov. 8, 2024

A unique and propitious [4 + 1] spiroannulation of 2-aryl-4

Language: Английский

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