Rhodium(III)‐Catalyzed Asymmetric [4+1] and [5+1] Annulation of Arenes and 1,3‐Enynes: A Distinct Mechanism of Allyl Formation and Allyl Functionalization DOI
Jiaqiong Sun, Weiliang Yuan, Rong Tian

et al.

Angewandte Chemie, Journal Year: 2020, Volume and Issue: 132(50), P. 22895 - 22902

Published: Sept. 4, 2020

Abstract We report chiral Rh III cyclopentadienyl‐catalyzed enantioselective synthesis of lactams and isochromenes through oxidative [4+1] [5+1] annulation, respectively, between arenes 1,3‐enynes. The reaction proceeds a C−H activation, alkenyl‐to‐allyl rearrangement, nucleophilic cyclization cascade. mechanisms the annulations were elucidated by combination experimental computational methods. DFT studies indicated that, following activation alkyne insertion, alkenyl intermediate undergoes δ ‐hydrogen elimination allylic via six‐membered ring transition state to produce enallene hydride intermediate. Subsequent insertion allyl rearrangement affords several rhodium(III) intermediates, rare η 4 ene‐allyl species with π‐agostic interaction SN 2 ′‐type external attack nitrogen nucleophile, instead C−N reductive elimination, as stereodetermining step.

Language: Английский

Lossen Rearrangement vs C–N Reductive Elimination Enabled by Rh(III)-Catalyzed C–H Activation/Selective Lactone Ring-Opening: Chemodivergent Synthesis of Quinolinones and Dihydroisoquinolinones DOI

Mengyao Bian,

Hamdulla Mawjuda,

Hui Gao

et al.

Organic Letters, Journal Year: 2020, Volume and Issue: 22(24), P. 9677 - 9682

Published: Dec. 4, 2020

An unprecedented Rh(III)-catalyzed cascade C–H activation/Lossen rearrangement of aromatic amides with methyleneoxetanones has been realized along a tunable C–N bond reductive elimination/trans esterification, giving divergent access to quinolinones and dihydroisoquinolinones via selective ring-opening the four-membered lactone unit. Combined computational experimental mechanistic studies defined solvent-involved distinguished reaction paths, origin observed chemodivergence, as well role substituent attached at oxidizing directing group in tuning outcomes.

Language: Английский

Citations

25
Construction of Rings via Metal‐Catalyzed C−H Annulation with Unsymmetrical Internal Alkynes: Selectivity and Applications DOI

Qiaoya Zhang,

Ci Chen,

Bairong Liu

et al.

ChemCatChem, Journal Year: 2023, Volume and Issue: 15(21)

Published: Aug. 19, 2023

Abstract Selective and concise construction of ring systems that are ubiquitous skeletons across chemistry, drugs materials, is indispensable for human life. Of note, directed C−H annulation with alkynes the expedient delivery holds great importance, featuring step‐ atom‐economy, mild conditions, broad substrate scope. However, regioselectivity issues remained when using unsymmetrical annulation. Herein, we summarized recent achievements towards solving this problem by developing directing groups, metal catalysts, versatile traceless functionality ensure overall regioselectivity, enantioselectivity, efficiency, synthetic application. We hope concept will promote further development precise functional molecules alkynes.

Language: Английский

Citations

8
Harnessing Rhodium-Catalyzed C–H Activation: Regioselective Cascade Annulation for Fused Polyheterocycles DOI
Maneesh Kumar Reddy Singam,

Undamatla Suri Babu,

Attunuri Nagireddy

et al.

The Journal of Organic Chemistry, Journal Year: 2021, Volume and Issue: 86(12), P. 8069 - 8077

Published: May 28, 2021

In the realm of transition-metal catalyzed arene functionalization, rhodium(III) catalysis is considered as exemplary due to its propensity activate C–H bonds obtain comprehensive molecular assembly. Herein, we demonstrate a new assembly polyheterocyclic scaffolds via activation and regioselective annulation 4-arylbut-3-yn-1-amines with 4-hydroxy-2-alkynoates. Heterocyclization trans-metalation prior key for initiation this relay redox-neutral catalytic cascade.

Language: Английский

Citations

20
Rhodium-catalyzed arylative cyclization of alkynyl malonates by 1,4-rhodium(i) migration DOI
Luke O’Brien,

Somnath Narayan Karad,

William Lewis

et al.

Chemical Communications, Journal Year: 2019, Volume and Issue: 55(76), P. 11366 - 11369

Published: Jan. 1, 2019

The synthesis of functionalized 1-tetralones by the rhodium(i)-catalyzed reaction alkynyl malonates with arylboronic acids is described. These arylative cyclizations proceed via an alkenyl-to-aryl 1,4-Rh(i) migration as a key step. Preliminary results enantioselective variant these reactions are also presented.

Language: Английский

Citations

21
A rhodium(iii)-catalyzed tunable coupling reaction of indole derivatives with alkylidenecyclopropanesviaC–H activation DOI

Ruixing Liu,

Yin Wei, Min Shi

et al.

Chemical Communications, Journal Year: 2019, Volume and Issue: 55(52), P. 7558 - 7561

Published: Jan. 1, 2019

A Rh(iii)-catalyzed coupling reaction of pyrimidineindoles with alkylidenecyclopropanes has been developed in the presence potassium chloride, affording functionalized alkenes moderate to good yields withE-configuration.

Language: Английский

Citations

19
Three-Component Iminolactonization Reaction via Bifunctionalization of Olefins Using Molecular Iodine and Visible Light DOI
Saki Maejima, Eiji Yamaguchi,

Akichika Itoh

et al.

The Journal of Organic Chemistry, Journal Year: 2020, Volume and Issue: 85(16), P. 10709 - 10718

Published: July 29, 2020

A novel three-component γ-iminolactonization reaction was developed, which relied on the C–C/C–O bond-forming bifunctionalization of olefins using molecular iodine and visible light. This strategy did not require any (heavy) metal reagents for double-bond activation because acted as a rare-metal-alternative reagent through light irradiation. In addition, preactivation amines other substrates is required. The mechanistic investigation revealed that generated radicals under irradiation reacted with alkenes to form highly reactive intermediate; then, diiodide, malonate, amine furnished iminolactone. Of note, developed simple realized diversity-oriented synthesis innovative methodology γ-iminolactone derivatives in drug discovery chemistry.

Language: Английский

Citations

18
Construction of Benzoxazinones from Anilines and Their Derivatives DOI
Tengfei Zhao,

Xiao-Li Xu,

Wei‐Yin Sun

et al.

Organic Letters, Journal Year: 2023, Volume and Issue: 25(27), P. 4968 - 4973

Published: July 3, 2023

Herein we report a strategy concerning Rh(III)-catalyzed direct ortho-C–H bond carbonylation to construct benzoxazinones from anilines and their derivatives with high atom economy. Interestingly, the corresponding amides were generated in situ when excess Ac2O was added directed following C–H form benzoxazinones. Extensive functional group tolerance can be achieved alkyl amide directing groups installed. Moreover, this method allows convenient derivatization of some drugs aryl amine show its potential application.

Language: Английский

Citations

6
Base-Promoted Chemodivergent Formation of 1,4-Benzoxazepin-5(4H)-ones and 1,3-Benzoxazin-4(4H)-ones Switched by Solvents DOI Creative Commons
Qian Chen, Yunpeng Wang, Ruimao Hua

et al.

Molecules, Journal Year: 2019, Volume and Issue: 24(20), P. 3773 - 3773

Published: Oct. 19, 2019

The KOH-promoted chemodivergent benzannulation of ortho-fluorobenzamides with 2-propyn-1-ol can afford either 1,4-benzoxazepin-5(4H)-ones or 1,3-benzoxazin-4(4H)-ones in good yields high selectivity, depending greatly upon the use solvents. In case using DMSO, intermolecular produced seven-membered benzo-fused heterocycles 1,4-benzoxazepin-5(4H)-ones, whereas MeCN, six-membered were formed. proceeded most probably through C–F nucleophilic substitution to give intermediate ortho-[(2-propynyl)oxy]benzamide, which underwent intramolecular hydroamidation a different manner seven- heterocycles.

Language: Английский

Citations

14
A Formal [3+2] Annulation of β‐Oxoamides and 3‐Alkyl‐ or 3‐Aryl‐Substituted Prop‐2‐Ynyl Sulfonium Salts: Substrate‐Controlled Chemoselective Synthesis of Substituted γ‐Lactams and Furans DOI

Bicheng Deng,

Chitturi Bhujanga Rao, Rui Zhang

et al.

Advanced Synthesis & Catalysis, Journal Year: 2019, Volume and Issue: 361(19), P. 4549 - 4557

Published: Aug. 6, 2019

Abstract A substrate‐controlled synthesis of substituted γ ‐lactams and furans has been developed via a formal [3+2] annulation β ‐oxoamides 3‐alkyl/arylprop‐2‐ynyl sulfonium salts in the presence cesium carbonate chemoselective manner. This novel protocol features easily available starting materials, mild reaction conditions, simple execution, good to excellent yields products. magnified image

Language: Английский

Citations

13
Rh-Catalyzed oxidative homo-coupling cyclization of 2,3-allenols to conjugated furylenones DOI
Xiaoyan Wu, Junjie Fan, Xin Huang

et al.

Organic Chemistry Frontiers, Journal Year: 2021, Volume and Issue: 8(16), P. 4432 - 4437

Published: Jan. 1, 2021

An unexpected rhodium-catalyzed highly regio- and stereo-selective bimolecular nucleophilic oxyrhodation/insertion/1,4-Rh migration/β-H elimination reaction of 2,3-allenols affording (2,5-dihydrofuran-3-yl)but-2(E)-en-1-one derivatives is reported.

Language: Английский

Citations

11