Stereoretentive Catalytic [3+2]-Cycloaddition/Rearrangement/Decarboxylation Reactions of Indoles with Non-Racemic Donor–Acceptor Cyclopropanes DOI
Ming Bao,

Karlos Lopez,

Raj K. Gurung

et al.

ACS Catalysis, Journal Year: 2023, Volume and Issue: 13(3), P. 1621 - 1629

Published: Jan. 12, 2023

A highly enantioselective synthesis of chiral dihydro-3H-carbazole-2-carboxylate derivatives is reported via a "one-pot" cyclopentannulation-rearrangement cascade reaction that sequentially catalyzed by nickel(II) perchlorate hexahydrate and scandium(III) trifluoromethanesulfonate with 3-methylindole non-racemic donor–acceptor cyclopropanes in high yields enantioretention under mild conditions. Highly diastereoselective [3+2]-cycloaddition dependent on substituents. In addition, further transformation these dihydro-3H-carbazole-2-carboxylates hydrolysis decarboxylation unexpectedly conditions provides straightforward access to the decarboxylated compounds moderate retention enantiomeric purity.

Language: Английский

Catalytic (3 + 2) annulation of donor–acceptor aminocyclopropane monoesters and indoles DOI Creative Commons
Vincent Pirenne, Emma G. L. Robert, Jérôme Waser

et al.

Chemical Science, Journal Year: 2021, Volume and Issue: 12(25), P. 8706 - 8712

Published: Jan. 1, 2021

A catalytic dearomatization of indoles with D–A aminocyclopropane monoesters for the synthesis highly substituted indolines.

Language: Английский

Citations

46
A novel type of donor–acceptor cyclopropane with fluorine as the donor: (3 + 2)-cycloadditions with carbonyls DOI Creative Commons
Haidong Liu, Lifang Tian, Hui Wang

et al.

Chemical Science, Journal Year: 2022, Volume and Issue: 13(9), P. 2686 - 2691

Published: Jan. 1, 2022

A new type of donor–acceptor cyclopropane with gem -difluorine as an unconventional donor group undergoes (3 + 2)-cycloadditions various aldehydes/ketones, affording densely functionalized -difluorotetrahydrofurans.

Language: Английский

Citations

33
1,3-Oxyalkynylation of Aryl Cyclopropanes with Ethylnylbenziodoxolones Using Photoredox Catalysis DOI
Zhijun Zuo, Armido Studer

Organic Letters, Journal Year: 2022, Volume and Issue: 24(3), P. 949 - 954

Published: Jan. 13, 2022

Alkynes and cyclopropanes are vital motifs in chemistry. Herein, a photoredox catalyzed 1,3-oxyalkynylation of aryl with ethylnylbenziodoxolones (EBXs) an atom-economic fashion is described. This cascade comprises single-electron oxidation the cyclopropane nucleophilic ring opening followed by radical alkynylation at benzylic position. The EBX compounds act as bifunctional reagents providing acid well alkynyl entity. introduced method features mild conditions wide substrate scope.

Language: Английский

Citations

30
Donor‐Acceptor Cyclopropanes: Activation Enabled by a Single, Vinylogous Acceptor DOI Creative Commons
Nils L. Ahlburg,

Oliver Hergert,

Peter G. Jones

et al.

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 62(1)

Published: Nov. 2, 2022

A novel class of highly activated donor-acceptor cyclopropanes bearing only a single, vinylogous acceptor is presented. These strained moieties readily undergo cycloadditions with aldehydes, ketones, thioketones, nitriles, naphth-2-ols and various other substrates to yield the corresponding carbo- heterocycles. Diastereocontrol can be achieved through choice catalyst (Brønsted or Lewis acid). The formation tetrahydrofurans was shown enantiospecific when chiral are employed. series mechanistic kinetic experiments conducted elucidate plausible catalytic cycle rationalize stereochemical outcome.

Language: Английский

Citations

29
Sterically Hindered and Deconjugative α‐Regioselective Asymmetric Mannich Reaction of Meinwald Rearrangement‐Intermediate DOI
Jinxiu Xu,

Yanji Song,

Jia Yang

et al.

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(13)

Published: Jan. 26, 2023

Compared to γ-addition, the α-addition of α-branched β,γ-unsaturated aldehydes faces larger steric hindrance and disrupts π-π conjugation, which might be why very few examples are reported. In this article, a highly diastereo- enantioselective α-regioselective Mannich reaction isatin-derived ketimines with α-, β- or γ-branched aldehydes, generated in situ from Meinwald rearrangement vinyl epoxides, is realized by using chiral N,N'-dioxide/ScIII catalysts. A series α-quaternary allyl homoallylic alcohols vicinal multisubstituted stereocenters constructed excellent yields, good d.r. ee values. Experimental studies DFT (density functional theory) calculations reveal that large ligand Boc (tButyloxy carbonyl) protecting group imines critical factors for α-regioselectivity.

Language: Английский

Citations

22
Cobalt-Catalyzed Asymmetric Dearomative [3 + 2] Annulation of Quinolines, Isoquinolines, and Pyridines DOI
Xingyu Wang, Xiaobing Wang, Tian Yin

et al.

ACS Catalysis, Journal Year: 2023, Volume and Issue: 13(17), P. 11528 - 11540

Published: Aug. 16, 2023

A highly enantioselective dearomative [3 + 2] annulation of quinolines, isoquinolines, and pyridines with donor–acceptor aminocyclopropanes was achieved. With C1-symmetric imidazoline-pyrroloimidazolone pyridine as the tridentate ligand Co(OTf)2 Lewis acid, diverse chiral indolizidine benzo-fused derivatives were obtained in good yields (up to 98% yield), excellent diastereoselectivities (>20:1 dr), enantioselectivities ee). Mechanistic experiments density functional theory (DFT) calculations revealed that nitrogen acted a bifunctional ligand. The not only coordinated Co(II) salt activate aminocyclopropane via bidentate coordination, but also formed H-bond oxygen atom succinimide moiety fix orientation aminocyclopropane, thus facilitating nucleophilic attack N-heteroaromatics. Additionally, high enantioselectivity reaction governed by steric factors.

Language: Английский

Citations

21
Synthesis of Cyclobutanes and Cyclobutenes by Strain-Release-Driven Ring-Opening of Bicyclo[1.1.0]butanes DOI

Xuan Zhan,

Heng-Xian He,

Quanxin Peng

et al.

Synthesis, Journal Year: 2024, Volume and Issue: 56(24), P. 3829 - 3848

Published: Aug. 23, 2024

Abstract Cyclobutanes and cyclobutenes exhibit intriguing structures demonstrate significant biological activities diverse synthetic applications. This review aims to summarize recent progress in strain-release-driven ring-opening reactions of bicyclo[1.1.0]butanes (BCBs) synthesize these four-membered carbon rings. It outlines the strategies, regio- stereoselectivity, scope reactions, mechanistic implications catalytic process, providing a supplementary perspective existing reviews. 1 Introduction 2 Thermally Driven Nucleophilic Ring-Opening 3 Rearrangement Isomerization Reaction 4 Light-Driven 5 Transition-Metal/Lewis Acid Catalyzed 6 Conclusion Outlook

Language: Английский

Citations

7
Organocatalytic Enantioselective (4+2) Annulation of Cyclopropane Carbaldehydes with 2‐Mercapto‐1‐Arylethanones DOI
Neeraj Yadav, Arijit Hazra, Priyanka Singh

et al.

Advanced Synthesis & Catalysis, Journal Year: 2024, Volume and Issue: 366(5), P. 1113 - 1119

Published: Jan. 23, 2024

Abstract Here, we report the organocatalytic enantioselective synthesis of dihydrothiopyran derivatives from trans racemic donor–acceptor cyclopropane carbaldehydes (DACCs) and 2‐mercapto‐1‐arylethanone via formal thio (4+2) cycloaddition involving thia‐Michael aldol condensation annulation. Mechanistic studies indicate a typical kinetic resolution (KR) is involved in this transformation, which results moderate yields enantiomeric ratios. Remarkably, method characterized by its one‐pot simplicity, mild reaction conditions, resilience towards air moisture interference.

Language: Английский

Citations

6
Sn(OTf)2-Catalyzed (3 + 2) Cycloaddition/Sulfur Rearrangement Reaction of Donor–Acceptor Cyclopropanes with Indoline-2-thiones DOI
Yan Jiang, Haojie Ma,

Chen-Ying Zhai

et al.

Organic Letters, Journal Year: 2024, Volume and Issue: 26(8), P. 1672 - 1676

Published: Feb. 15, 2024

The (3 + 2) cycloaddition/sulfur rearrangement reaction of donor–acceptor cyclopropanes bearing a single keto acceptor with indoline-2-thiones has been realized. Under the catalysis Sn(OTf)2, series functionalized 3-indolyl-4,5-dihydrothiophenes were synthesized moderate to excellent yields.

Language: Английский

Citations

6
Recent Advances in Stereoselective Ring Expansion of Spirocyclopropanes: Access to the Spirocyclic Compounds DOI Creative Commons
Tanumay Sarkar,

Bijay Ketan Das,

Kangkan Talukdar

et al.

ACS Omega, Journal Year: 2020, Volume and Issue: 5(41), P. 26316 - 26328

Published: Oct. 7, 2020

Spirocyclopropane represents a privileged structural scaffold for accessing synthetic libraries of densely functionalized spirocarbo- and heterocyclic compounds. Due to the ubiquity spirocyclic motifs as potent pharmacophore in natural products pharmaceuticals, recent years have witnessed significant advances developing strategies that exploits carbon–carbon bond scission spirocyclopropanes. This paper summarizes developments stereoselective ring expansion spirocyclopropanes diversity-oriented synthesis highlights well mechanistic rationale those methodologies. review also encompasses applicability protocols bioactive product syntheses.

Language: Английский

Citations

42