Photocatalytic Phosphine-Mediated Deoxygenative [3 + 2] Cycloaddition of α,β-Unsaturated Carbonyls and Alkenes DOI

Jiayan Qiu,

Xuemei Zhang,

Hanliang Zheng

et al.

Journal of the American Chemical Society, Journal Year: 2025, Volume and Issue: unknown

Published: May 22, 2025

Tertiary phosphine is a powerful nucleophile that enables numerous synthetically important reactions. However, the exclusive reliance on two-electron pathway has restricted development of chemistry. We report here visible light photocatalytic phosphine-mediated deoxygenative [3 + 2] cycloaddition α,β-unsaturated carbonyls and activated alkenes, providing facile access to polysubstituted cyclopentenes from readily accessible starting materials in promising yields with good substrate scope. Mechanistic investigations corroborate transient involvement radical cation consequent α-addition (α electron-withdrawing groups) C-C double bonds due inherent electrophilicity cation, as opposed traditional nucleophilic β-addition phosphine. The ensuing single electron transfer reduction, Michael addition, 1,4-proton cascade furnish phosphorus ylide, which undergoes an intramolecular Wittig reaction finish construction cyclopentenes. This work demonstrates tertiary can serve convenient reagent for carbonyl deoxygenation act traceless directing group controllable cross-coupling two distinct new avenues expand frontiers chemistry synthetic

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
A Radical Precursor Based on the Aromatization of p-Quinol Esters Enabled by Pyridine-Boryl Radical DOI
Xiaoli Huang,

Ruji Xiong,

Yi Cui

et al.

The Journal of Organic Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 13, 2025

A class of prearomatic carboxylic acid p-quinol ester radical precursors has been developed successfully, which could undergo homolytic cleavage the para C-O bond esters via pyridine-boryl radical-induced aromatization in presence pyridines and diboron reagents, affording corresponding alkyl decarboxylation from carboxyl situ. In addition, were further applied substitution with phenylsulfonyl compounds self-coulpings. This method not only provides a new approach to generation intermediate but also expands application boron radicals.

Language: Английский

Citations

0
Synthesis of gem-Diborylcyclopropyl Ketones via Conjugate Addition of Chlorodiborylmethane to α,β-Unsaturated Ketones DOI
Shuang Xu,

Peng‐Fei Ning,

Yi Wei

et al.

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

Published: April 3, 2025

The carbanion derived from chlorodiborylmethane can act as a soft nucleophile, while the halogen substituent subsequently function leaving group. Taking advantage of this feature, we herein have developed an efficient synthesis gem-diborylcyclopropyl ketones diverse range enone substrates. We also demonstrated synthetic utility protocol by leveraging highly transformable nature cyclopropyl moiety and C-B bonds.

Language: Английский

Citations

0
Photocatalytic Phosphine-Mediated Deoxygenative [3 + 2] Cycloaddition of α,β-Unsaturated Carbonyls and Alkenes DOI

Jiayan Qiu,

Xuemei Zhang,

Hanliang Zheng

et al.

Journal of the American Chemical Society, Journal Year: 2025, Volume and Issue: unknown

Published: May 22, 2025

Tertiary phosphine is a powerful nucleophile that enables numerous synthetically important reactions. However, the exclusive reliance on two-electron pathway has restricted development of chemistry. We report here visible light photocatalytic phosphine-mediated deoxygenative [3 + 2] cycloaddition α,β-unsaturated carbonyls and activated alkenes, providing facile access to polysubstituted cyclopentenes from readily accessible starting materials in promising yields with good substrate scope. Mechanistic investigations corroborate transient involvement radical cation consequent α-addition (α electron-withdrawing groups) C-C double bonds due inherent electrophilicity cation, as opposed traditional nucleophilic β-addition phosphine. The ensuing single electron transfer reduction, Michael addition, 1,4-proton cascade furnish phosphorus ylide, which undergoes an intramolecular Wittig reaction finish construction cyclopentenes. This work demonstrates tertiary can serve convenient reagent for carbonyl deoxygenation act traceless directing group controllable cross-coupling two distinct new avenues expand frontiers chemistry synthetic

Language: Английский

Citations

0