Chiral Phosphoric Acid-Catalyzed Enantioselective Synthesis of 2,2-Disubstituted 2,3-Dihydro-4-quinolones from Isatins and 2′-Aminoacetophenones DOI

Hidenori Andatsu,

Yuto Terashima,

Ryota Kawamura

et al.

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

Published: Dec. 24, 2024

Herein, we present the enantioselective synthesis of 2,3-dihydro-4-quinolones bearing chiral tetrasubstituted carbons from isatins and 2′-aminoacetophenones. The transformation is mediated by a phosphoric acid catalyst proceeds via an in situ generated ketimine subsequent intramolecular cyclization. methodology features broad scope functional group tolerance with yields enantioselectivities up to 99% 98% ee. Detailed density theory (DFT) calculations support proposed reaction mechanism origin asymmetric induction.

Language: Английский

Lewis Acid-Enabled Chemodivergent Cycloadditions of Donor–Acceptor Cyclopropanes with Indoline-2-Thiones DOI

Chen-Ying Zhai,

Bing Zhao, Xuelong Wang

et al.

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

Published: Feb. 20, 2025

Lewis acid-enabled reactions of donor-acceptor cyclopropanes (DACs) with indoline-2-thiones are reported. The reaction exhibits tunable annulation depending on the acid and substituent at N1 indoline-2-thiones. With AlCl3 as 1-isopropylindoline-2-thiones reactants, a direct ring opening DACs, followed by intramolecular nucleophilic addition/dehydration takes place leading to formation dihydro-2H-thiepino[2,3-b]indoles in moderate good yields. Using Yb(OTf)3 promoter 1-unsubstituted (3 + 2) cycloaddition DACs accompanied sulfur rearrangement give 3-indolyl-4,5-dihydrothiophenes In addition, synthetic transformation 3-indolyl-4,5-dihydrothiophene sulfone indole-based axially chiral scaffolds further extends utility structural complexity.

Language: Английский

Citations

1
P(═O)R2-Directed Asymmetric Catalytic C–H Olefination Leading to C–N Axially Chiral Targets DOI

Shengzhou Jin,

Yu Wang, Jun Yan

et al.

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

Published: March 11, 2025

A novel P(═O)R2-directed asymmetric catalytic olefination has been developed, enabling efficient access to carbon–nitrogen axially chiral products with excellent yields (up 92%) and enantioselectivity 99% enantiomeric excess). The synergistic coordination of phosphine oxide functionality l-pGlu-OH the Pd metal center, serving as an directing group ligand, was key success this C–H functionalization system. reaction demonstrated a broad substrate scope, yielding 33 distinct C–N axial products. absolute configuration unambiguously confirmed via X-ray diffraction analysis. Additionally, three representative applications were showcased, involving reduction oxidation produce phosphines related derivatives. plausible cycle mechanism proposed, supported by detailed experimental studies. Aggregates in system identified aggregation-induced polarization experiments.

Language: Английский

Citations

0
Palladium-Catalyzed (3 + 2) Annulation of Azaborines with Vinyl Epoxides for Constructing Polycyclic Oxazaborolidines DOI

Ziqi Zhu,

Ding-Hao Ge,

Zhijie Cao

et al.

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

Published: March 25, 2025

A palladium-catalyzed (3 + 2) annulation of azaborines with vinyl epoxides has been established. By this strategy, various polycyclic oxazaborolidines structural diversity were synthesized in generally high yields (up to 99%). The can be scaled up and the further functionalized through olefin metathesis Heck reaction, which demonstrated good feasibility for downstream transformations. Moreover, catalytic asymmetric version accomplished under catalysis palladium/chiral phosphoramidite ligand, producing chiral overall enantioselectivities 98:2 er). This work not only represents first 1,2-azaborines but also offers an efficient strategy constructing benzooxazaborolidine skeletons, particularly those enantioenriched fashion.

Language: Английский

Citations

0
Enantioselective Desymmetrization of Biaryls via Cooperative Photoredox/Brønsted Acid Catalysis and Its Application to the Total Synthesis of Ancistrobrevolines DOI

Junsoo Moon,

Eun Joo Shin, Yongseok Kwon

et al.

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

Published: April 5, 2025

Photoredox catalysis has emerged as a powerful tool for forming and breaking chemical bonds, further taking hold with its integration asymmetric catalysis. While the dual-catalytic approach led to successful examples of control stereogenic centers, axes remained underexplored. In this study, an acylimine intermediate was generated through photoredox catalysis, symmetric substrate, 2-arylresorcinol, desymmetrized aid chiral phosphoric acid Using approach, center axis were successfully controlled provide natural-product-driven compound. The origins enantioselectivity diastereoselectivity investigated density functional theory study four possible enantiodetermining transition states. Consequently, first total syntheses ring-contracted naphthylisoquinoline alkaloid ancistrobrevolines A B accomplished concisely. This provides not only novel methodology strategy synthesize alkaloids but also direction advance catalytic research synthesis studies.

Language: Английский

Citations

0
Remote Copper-Catalyzed Atroposelective Synthesis of N–N Axially Chiral Compounds Bearing Minimally Different Alkyl Groups DOI

Zhaoliang Ge,

Cuiju Zhu,

Guang Xu

et al.

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

Published: May 25, 2025

Herein, we report a copper-catalyzed remote asymmetric [4+1] annulation/aromatization between yne-allylic esters and N-aminoindoles, providing axially chiral N,N'-indolepyrroles that contain sterically comparable ortho substituents, such as methyl ethyl. This reaction proceeds smoothly under mild conditions, affording products with excellent regio- enantioselectivities while demonstrating broad functional group compatibility. The synthetic utility of this approach is further showcased through the late-stage modification biologically relevant scaffolds. Additionally, preliminary mechanistic investigations indicate nucleophilic substitution enantio-determining step.

Language: Английский

Citations

0
Enantioselective Synthesis of Benzodihydrofurans Bearing Axial and Central Stereogenic Elements DOI Creative Commons

Antoine Domain,

Xiaoze Bao,

Jean Rodriguez

et al.

Chemistry - A European Journal, Journal Year: 2024, Volume and Issue: 30(69)

Published: Sept. 27, 2024

Abstract The enantioselective synthesis of chiral compounds containing multiple stereogenic elements via a single catalytic step is challenging process. In the presence α‐chloronitrostyrenes and squaramide catalyst, C−C or C−N pro‐axially 2‐naphthol substrates, featuring low barriers to enantiomerization, underwent remote diastereo‐ domino Michael/ O ‐alkylation. It provided desired benzodihydrofurans bearing two carbon atoms configurationally stable bond, thanks high increase barrier rotation upon dihydrofurannulation.

Language: Английский

Citations

2
Bro̷nsted Acid-Catalyzed Regioselective [5 + 1] Annulation for the Synthesis of Indole-Fused Dihydrochromanes DOI
Siyi Liu, Lu Fan,

Ziqi Zhu

et al.

The Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 89(22), P. 16791 - 16803

Published: Nov. 3, 2024

A Bro̷nsted acid-catalyzed [5 + 1] annulation of 2-(1

Language: Английский

Citations

2
Photo-Promoted Construction of 3-Spiro-2-sulfonylimino-indoline Skeletons via Cascade Reaction DOI

Yuliang Wei,

Jiaxi Xu

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

Published: Dec. 25, 2024

The cascade reaction of 3-diazo-2-sulfonyliminoindolines and N-methoxymethyl-N-[(trimethylsilyl)methyl]benzylamines generates 2-sulfonylimino-1′,3′,4′,6′-tetrahydro-2'H-spiro[indoline-3,5′-pyrimidine] spiro[indoline-3,3′-pyrrolidine] derivatives simultaneously under the catalysis TFA blue light irradiation. Their formation mechanisms were proposed on basis isotope-labeled experiments HRMS analysis controlled experiment mixture, showing new pathways. current provides a strategy for synthesis biologically important spiro[indoline-3,3′-pyrrolidine]-2-one derivatives.

Language: Английский

Citations

1
Site-Selective Electrophilic Trifluoromethylthiolation for the Synthesis of C5- or C7-SCF3-Substituted Indolines DOI
Xiaolong Wang, Yan Fu,

Zhenshan Guo

et al.

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

Published: Dec. 23, 2024

We report herein an efficient and site-selective electrophilic trifluoromethylthiolation of indolines. In the absence any catalyst or additive, C5-selective could proceed at room temperature. With palladium used as catalyst, selectivity was reversed completely, giving C7-selecive trifluoromethylthiolated products. This reaction features good functional group tolerance, simple operation, mild conditions, scale-up application. The potential utilities products were shown by further transformations.

Language: Английский

Citations

0
Chiral Phosphoric Acid-Catalyzed Enantioselective Synthesis of 2,2-Disubstituted 2,3-Dihydro-4-quinolones from Isatins and 2′-Aminoacetophenones DOI

Hidenori Andatsu,

Yuto Terashima,

Ryota Kawamura

et al.

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

Published: Dec. 24, 2024

Herein, we present the enantioselective synthesis of 2,3-dihydro-4-quinolones bearing chiral tetrasubstituted carbons from isatins and 2′-aminoacetophenones. The transformation is mediated by a phosphoric acid catalyst proceeds via an in situ generated ketimine subsequent intramolecular cyclization. methodology features broad scope functional group tolerance with yields enantioselectivities up to 99% 98% ee. Detailed density theory (DFT) calculations support proposed reaction mechanism origin asymmetric induction.

Language: Английский

Citations

0