Homologation of Alkenyl Carbonyls via a Cyclopropanation/Light‐Mediated Selective C‐C Cleavage Strategy DOI
Tin V. T. Nguyen, Duncan K. Brownsey, André Bossonnet

et al.

Angewandte Chemie, Journal Year: 2024, Volume and Issue: unknown

Published: Oct. 31, 2024

Abstract We report herein our studies on the direct photoactivation of carbonyl cyclopropanes to give biradical intermediates, leading selective cleavage more substituted carbon‐carbon bond. Depending substrate structure, extended alkenes were isolated or directly reacted in a photo‐Nazarov process bicyclic products. Based these results, unified reductive ring‐opening reaction was developed by using diphenyl disulfide as hydrogen atom transfer (HAT) reagent. By performing sequential cyclopropanation/selective ring opening reaction, we achieved CH 2 insertion into α,β bond both acyclic and cyclic unsaturated compounds. Our protocol provides further tool for modification carbon framework organic compounds, complementing recent progress “skeletal editing”.

Language: Английский

Merging Ketyl Radical Chemistry and Allylboration via Strain Release: One-Pot Multicomponent Access to Sterically Congested Ketone-Functionalized Organoborons DOI

Aiswarya Mini,

Het Vyas, Ashvin J. Gangani

et al.

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

Published: March 17, 2025

Ketyl radical-mediated ring opening and [2σ+2π] cycloaddition of cyclopropyl ketones (CPKs) with alkynes typically require activation by alkyl, aryl, or carbonyl groups yielding cyclopentenes having one two non-adjacent stereocenters. We developed a one-pot multicomponent reaction diboryl-activated CPKs aldehydes that merges ketyl radical chemistry allylboration. This method enabled highly diastereoselective access to densely functionalized featuring homoallylic alcohol, ketone, alkenyl boronate motifs on adjacent quaternary, tertiary, secondary stereogenic centers. Additionally, diboryl also allowed the synthesis rare ketone-functionalized γ,γ-disubstituted allylic diborons.

Language: Английский

Citations

2
Regio‐ and Diastereoselective Synthesis of Polysubstituted Piperidines Enabled by Boronyl Radical‐Catalyzed (4+2) Cycloaddition DOI
Zhengwei Ding, Zhijun Wang, Yingying Wang

et al.

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(38)

Published: June 26, 2024

Piperidines are widely present in small molecule drugs and natural products. Despite many methods have been developed for their synthesis, new approaches to polysubstituted piperidines highly desirable. This work presents a radical (4+2) cycloaddition reaction synthesis of featuring dense substituents at 3,4,5-positions that not readily accessible by known methods. Using commercially available diboron(4) compounds 4-phenylpyridine as the catalyst precursors, boronyl radical-catalyzed between 3-aroyl azetidines various alkenes, including previously unreactive 1,2-di-, tri-, tetrasubstituted has delivered generally high yield diastereoselectivity. The also features modularity, atom economy, broad substrate scope, metal-free conditions, simple catalysts operation. utilization products demonstrated selective transformations. A plausible mechanism, with ring-opening azetidine rate-limiting step, proposed based on experimental computational results.

Language: Английский

Citations

4
Broad-Scope (3 + 2) Cycloaddition of Cyclopropanes and Alkynes Enabled by Boronyl Radical Catalysis DOI

Jingru Wen,

Zhengwei Ding, Pengfei Li

et al.

Organic Letters, Journal Year: 2024, Volume and Issue: 26(33), P. 7021 - 7025

Published: Aug. 14, 2024

Cyclopentene skeletons are ubiquitous in natural products and small molecule drugs. The (3 + 2) cycloaddition of cyclopropanes alkynes represents an efficient atom-economic strategy for synthesizing these structures. However, the types substituents on cyclopropane alkyne used previous works show evident limitations, restricting application this type reaction to some extent. Herein, we report a broad-scope catalyzed by boronyl radicals. In method, various substrates, such as mono-, di-, tri-, tetrasubstituted cyclopropanes, well mono- disubstituted alkynes, were compatible with up 98% isolated yield.

Language: Английский

Citations

4
Photodriven Sm(III)-to-Sm(II) Reduction for Catalytic Applications DOI Creative Commons
Christian M. Johansen, Emily A. Boyd,

Drew E. Tarnopol

et al.

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(37), P. 25456 - 25461

Published: Sept. 3, 2024

The selectivity of SmI

Language: Английский

Citations

4
Homologation of Alkenyl Carbonyls via a Cyclopropanation/Light‐Mediated Selective C‐C Cleavage Strategy DOI Creative Commons
Tin V. T. Nguyen, Duncan K. Brownsey, André Bossonnet

et al.

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: unknown

Published: Oct. 31, 2024

We report herein our studies on the direct photoactivation of carbonyl cyclopropanes to give biradical intermediates, leading selective cleavage more substituted carbon-carbon bond. Depending substrate structure, extended alkenes were isolated or directly reacted in a photo-Nazarov process bicyclic products. Based these results, unified reductive ring-opening reaction was developed by using diphenyl disulfide as hydrogen atom transfer (HAT) reagent. By performing sequential cyclopropanation/selective ring opening reaction, we achieved CH

Language: Английский

Citations

1
Photocatalyst for Visible-Light-Driven Sm(II)-Mediated Reductions DOI Creative Commons
Monika Tomar,

Caroline Bosch,

Jules Everaert

et al.

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

Published: Dec. 11, 2024

Commercially available coumarin 343 in combination with reducible Sm(III) ions catalyzed divalent lanthanide-mediated C═O, C-halogen, P-Cl, and N═N reductions at ambient temperature aqueous solvent mixtures. The catalyst absorbs visible light efficiently. active species is formed by photoinduced electron transfer from to the stable trivalent precursor, could be regenerated strictly 1 equiv of ascorbic acid.

Language: Английский

Citations

1
Regio‐ and Diastereoselective Synthesis of Polysubstituted Piperidines Enabled by Boronyl Radical‐Catalyzed (4+2) Cycloaddition DOI
Zhengwei Ding, Zhijun Wang, Yingying Wang

et al.

Angewandte Chemie, Journal Year: 2024, Volume and Issue: 136(38)

Published: June 26, 2024

Abstract Piperidines are widely present in small molecule drugs and natural products. Despite many methods have been developed for their synthesis, new approaches to polysubstituted piperidines highly desirable. This work presents a radical (4+2) cycloaddition reaction synthesis of featuring dense substituents at 3,4,5‐positions that not readily accessible by known methods. Using commercially available diboron(4) compounds 4‐phenylpyridine as the catalyst precursors, boronyl radical‐catalyzed between 3‐aroyl azetidines various alkenes, including previously unreactive 1,2‐di‐, tri‐, tetrasubstituted has delivered generally high yield diastereoselectivity. The also features modularity, atom economy, broad substrate scope, metal‐free conditions, simple catalysts operation. utilization products demonstrated selective transformations. A plausible mechanism, with ring‐opening azetidine rate‐limiting step, proposed based on experimental computational results.

Language: Английский

Citations

0
Computational Study of SmI2-Catalyzed Intermolecular Couplings of Cyclopropyl Ketones: Links between the Structure and Reactivity DOI Creative Commons
Song Yu, Ciro Romano, David J. Procter

et al.

The Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: unknown

Published: Oct. 22, 2024

SmI

Language: Английский

Citations

0
Homologation of Alkenyl Carbonyls via a Cyclopropanation/Light‐Mediated Selective C‐C Cleavage Strategy DOI
Tin V. T. Nguyen, Duncan K. Brownsey, André Bossonnet

et al.

Angewandte Chemie, Journal Year: 2024, Volume and Issue: unknown

Published: Oct. 31, 2024

Abstract We report herein our studies on the direct photoactivation of carbonyl cyclopropanes to give biradical intermediates, leading selective cleavage more substituted carbon‐carbon bond. Depending substrate structure, extended alkenes were isolated or directly reacted in a photo‐Nazarov process bicyclic products. Based these results, unified reductive ring‐opening reaction was developed by using diphenyl disulfide as hydrogen atom transfer (HAT) reagent. By performing sequential cyclopropanation/selective ring opening reaction, we achieved CH 2 insertion into α,β bond both acyclic and cyclic unsaturated compounds. Our protocol provides further tool for modification carbon framework organic compounds, complementing recent progress “skeletal editing”.

Language: Английский

Citations

0