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

Exploiting Heavier Organochalcogen Compounds in Donor–Acceptor Cyclopropane Chemistry DOI
André U. Augustin, Daniel B. Werz

Accounts of Chemical Research, Journal Year: 2021, Volume and Issue: 54(6), P. 1528 - 1541

Published: March 4, 2021

ConspectusDonor–acceptor (D–A) cyclopropanes have gained increased momentum over the past two decades. The use of these highly strained three-membered entities paved way to innovative and original transformations yielding complex cyclic acyclic architectures that otherwise might be difficult address. Since fundamentals were laid by Wenkert Reissig in late 1970s, field has flourished impressively including asymmetric as well elegant synthetic applications construction natural occurring products. In this Account, we aim highlight especially our efforts context an efficient access sulfur- selenium-containing compounds, either or open-chain nature, exploiting D–A cyclopropane chemistry. Light will shed on three fundamental transformations: ring-opening reactions, cycloadditions, rearrangements.Our endeavors started back 2011 guided quantum chemical studies obtain 3,3′-linked bisthiophenes along with unprecedented rearrangement delivering cagelike scaffolds. Inspired surprising results, further deepened new sulfur–carbon selenium–carbon bonds within first instance, capitalized great versatility organosulfur organoselenium compounds regarding their amphiphilic character act nucleophilic electrophilic species. By such approach, ring-openings via a attack sulfenyl selenyl halides furnished 1,3-bishalochalcogenated A similar protocol led us desymmetrization reaction meso-cyclopropyl carbaldehydes employing novel chiral imidazolidinone organocatalysts. contrast, sulfur was supplied N-(arylthio)succinimide substrates thiolated γ-amino acid derivatives selenium equivalents.Combining reactive thiocarbonyl vicinal donor–acceptor substituted opened vistas atom-economic cycloaddition reactions build up sulfur-containing heterocycles various sizes. systematic study made group 2017 leading decorated thiolanes, whereas intramolecular approach thia-[n.2.1]bicyclic ring systems. Our investigations then successfully extended synthesis tetrahydroselenophenes using capricious selenoketones. Recently, able yield unsaturated analogues, selenophenes, (3 + 2)-cycloaddition ammonium selenocyanates followed oxidation. formal insertion thioketenes realized 3-thioxocyclobutanones surrogates for disubstituted 2-substituted tetrahydrothiophenes bearing semicyclic double bond 2) spiroannulation/(2 cycloreversion sequence. Even formation seven-membered S-heterocycles (4 3)-cycloaddition processes. 2016, demonstrated benzo-fused dithiepines from situ generated ortho-bisthioquinones, utilization thia-Michael systems hetero-4π-component delivered tetrahydrothiepine containing just one atom embedded system.

Language: Английский

Citations

131
Cooperative NHC/Photoredox Catalyzed Ring‐Opening of Aryl Cyclopropanes to 1‐Aroyloxylated‐3‐Acylated Alkanes DOI
Zhijun Zuo, Constantin G. Daniliuc, Armido Studer

et al.

Angewandte Chemie International Edition, Journal Year: 2021, Volume and Issue: 60(48), P. 25252 - 25257

Published: Sept. 28, 2021

Cyclopropanes are an important class of building blocks in organic synthesis. Herein, a ring-opening/arylcarboxylation/acylation cascade reaction for the 1,3-difunctionalization aryl cyclopropanes enabled by cooperative NHC and organophotoredox catalysis is reported. The works on monosubstituted that contrast to heavily investigated donor-acceptor more challenging be difunctionalized. key step radical/radical cross coupling benzylic radical generated photoredox cycle with ketyl from cycle. transformation features metal-free conditions tolerates diverse range functionalities.

Language: Английский

Citations

116
High-order dipolar annulations with metal-containing reactive dipoles DOI
Mao‐Mao Zhang,

Bao‐Le Qu,

Bin Shi

et al.

Chemical Society Reviews, Journal Year: 2022, Volume and Issue: 51(10), P. 4146 - 4174

Published: Jan. 1, 2022

The advances on metal-catalysed high-order dipolar annulations were comprehensively summarized in this review. To further exploit the potential of unique annulation strategy, a research outlook was also proposed.

Language: Английский

Citations

88
Intermolecular Formal Cycloaddition of Indoles with Bicyclo[1.1.0]butanes by Lewis Acid Catalysis DOI Open Access
Dongshun Ni,

Sai Hu,

Xiangyu Tan

et al.

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(48)

Published: Aug. 16, 2023

Abstract Herein, we develop a new approach to directly access architecturally complex polycyclic indolines from readily available indoles and bicyclo[1.1.0]butanes (BCBs) through formal cycloaddition promoted by commercially Lewis acids. The reaction proceeded stepwise pathway involving nucleophilic addition of BCBs followed an intramolecular Mannich form rigid indoline‐fused structures, which resemble indole alkaloids. This tolerated wide range BCBs, thereby allowing the one‐step construction various indoline polycycles containing up four contiguous quaternary carbon centers.

Language: Английский

Citations

78
Enantioselective formal (3 + 3) cycloaddition of bicyclobutanes with nitrones enabled by asymmetric Lewis acid catalysis DOI Creative Commons
Wen‐Biao Wu, Bing Xu, Xue-Chun Yang

et al.

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: Sept. 12, 2024

Language: Английский

Citations

21
Zinc‐Catalyzed Enantioselective Formal (3+2) Cycloadditions of Bicyclobutanes with Imines: Catalytic Asymmetric Synthesis of Azabicyclo[2.1.1]hexanes DOI Open Access
Feng Wu, Wen‐Biao Wu, Yuanjiu Xiao

et al.

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(48)

Published: Sept. 2, 2024

Abstract The cycloaddition reaction involving bicyclo[1.1.0]butanes (BCBs) offers a versatile and efficient synthetic platform for producing C(sp 3 )‐rich rigid bridged ring scaffolds, which act as phenyl bioisosteres. However, there is scarcity of catalytic asymmetric cycloadditions BCBs to fulfill the need enantioenriched saturated bicycles in drug design development. In this study, an synthesis valuable azabicyclo[2.1.1]hexanes (aza‐BCHs) by enantioselective zinc‐catalyzed (3+2) with imines reported. proceeds effectively novel type BCB that incorporates 2‐acyl imidazole group diverse array alkynyl‐ aryl‐substituted imines. target aza‐BCHs, consist α‐chiral amine fragments two quaternary carbon centers, are efficiently synthesized up 94 % 96.5:3.5 er under mild conditions. Experimental computational studies reveal follows concerted nucleophilic ring‐opening mechanism This distinct from previous on Lewis acid‐catalyzed BCBs.

Language: Английский

Citations

20
Hexafluoroisopropanol Promoted Ring‐Opening‐Cyclization of Donor–Acceptor Cyclopropanes with Primary Amines DOI
Srinivasarao Yaragorla,

Rajeshwari Tangellapally,

Doma Arun

et al.

European Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 27(22)

Published: March 19, 2024

Abstract We reveal here a catalyst‐free, ring‐opening‐cyclization of donor‐acceptor cyclopropanes with primary amines to synthesize functionalized dihydropyrroles. This protocol avoids inert conditions and solvents promoted by hexafluoroisopropanol (HFIP). The reaction is quite general aryl, alkyl, alicyclic amines. A good number bearing keto groups reacted excellently produce the desired products. Further, we complemented this method Meldrum's acid‐derived for synthesizing γ‐lactams. have demonstrated post‐synthetic applications products gram‐scale synthesis highlight adaptability synthetic protocol.

Language: Английский

Citations

9
Ring Expansion toward Fused Diazabicyclo[3.1.1]heptanes through Lewis Acid Catalyzed Highly Selective C−C/C−N Bond Cross‐Exchange Reaction between Bicyclobutanes and Diaziridines DOI
Heng-Xian He, Feng Wu, Xu Zhang

et al.

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

Published: Nov. 13, 2024

Abstract The synthesis of bicyclic scaffolds has garnered considerable interest in drug discovery because their ability to mimic benzene bioisosteres. Herein, we introduce a new approach that utilizes Lewis acid (Sc(OTf) 3 )‐catalyzed σ‐bond cross‐exchange reaction between the C−C bond bicyclobutanes and C−N diaziridines produce multifunctionalized medicinally interesting azabicyclo[3.1.1]heptane derivatives. proceeds well with different broad range aryl‐ as alkenyl‐, but also alkyl‐substituted (up 98 % yield). Conducting scale‐up experiment exploring synthetic transformations cycloadducts emphasized practical application synthesis. Furthermore, zinc‐based chiral catalytic system was developed for enantioselective version this 96 ee ).

Language: Английский

Citations

9
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
Palladium-catalyzed enantioselective [2σ + 2π] cycloadditions of vinyl-carbonyl-bicyclo[1.1.0]butanes with arylidenemalononitriles DOI

Tianzhu Qin,

Weiwei Zi

Chinese Chemical Letters, Journal Year: 2025, Volume and Issue: unknown, P. 111072 - 111072

Published: March 1, 2025

Language: Английский

Citations

1