Tandem Synthesis of 2-Azaspiro[4.5]deca-1,6,9-trien-8-ones Based on Tf2O-Promoted Activation of N-(2-Propyn-1-yl) Amides DOI

Lidong Shan,

Hongchen Li, Weiping Zheng

et al.

The Journal of Organic Chemistry, Journal Year: 2022, Volume and Issue: 88(1), P. 525 - 533

Published: Dec. 16, 2022

Structurally novel 2-azaspiro[4.5]deca-1,6,9-trien-8-ones were synthesized from N-(2-propyn-1-yl) amides and 1,3,5-trimethoxybenzenes by a tandem method consisting of Tf2O-promoted amide activation TfOH-promoted Friedel-Crafts ipso-cyclization. The offered the first example using as substrates in both secondary synthesis azaspiro[4.5]deca-6,9-diene-8-ones.

Language: Английский

Rhodium-Catalyzed Asymmetric C–H Functionalization Reactions DOI
Chen‐Xu Liu,

Si‐Yong Yin,

Fangnuo Zhao

et al.

Chemical Reviews, Journal Year: 2023, Volume and Issue: 123(16), P. 10079 - 10134

Published: Aug. 1, 2023

This review summarizes the advancements in rhodium-catalyzed asymmetric C–H functionalization reactions during last two decades. Parallel to rapidly developed palladium catalysis, rhodium catalysis has attracted extensive attention because of its unique reactivity and selectivity reactions. In recent years, Rh-catalyzed have been significantly many respects, including catalyst design, reaction development, mechanistic investigation, application synthesis complex functional molecules. presents an explicit outline catalysts ligands, mechanism, scope coupling reagents, applications.

Language: Английский

Citations

122

C–H activation-initiated spiroannulation reactions and their applications in the synthesis of spirocyclic compounds DOI

Qianting Zhou,

Bin Li, Xinying Zhang

et al.

Organic & Biomolecular Chemistry, Journal Year: 2024, Volume and Issue: 22(12), P. 2324 - 2338

Published: Jan. 1, 2024

This review summarizes the most recent progress made in C–H bond activation-initiated spiroannulation reactions and their applications construction of structurally diverse biologically valuable spirocyclic scaffolds.

Language: Английский

Citations

22

Synthesis of Spiro[benzo[d][1,3]oxazine-4,4′-isoquinoline]s via [4+1+1] Annulation of N-Aryl Amidines with Diazo Homophthalimides and O2 DOI

Qianting Zhou,

Xia Song,

Xinying Zhang

et al.

Organic Letters, Journal Year: 2022, Volume and Issue: 24(6), P. 1280 - 1285

Published: Feb. 7, 2022

Synthesis of spiro[benzo[d][1,3]oxazine-4,4'-isoquinoline]s through a unique [4+1+1] annulation N-aryl amidines with diazo homophthalimides and O2 is presented. This unprecedented spirocyclization reaction features readily obtainable substrates, structurally pharmaceutically attractive products, cost-free clean oxygen source, sustainable medium, tolerance broad spectrum functional groups, an interesting mechanism based on sequential C(sp2)-H/C(sp3)-H bond cleavage insertion.

Language: Английский

Citations

49

Tunable Key [3 + 2] and [2 + 1] Cycloaddition of Enaminones and α-Diazo Compounds for the Synthesis of Isomeric Isoxazoles: Metal-Controlled Selectivity DOI
Wenli Song, Yunyun Liu, Nan Yan

et al.

Organic Letters, Journal Year: 2023, Volume and Issue: 25(12), P. 2139 - 2144

Published: March 22, 2023

The three-component reactions of enaminones, α-diazo esters/ketones, and t-butyl nitrite (TBN) for the switchable synthesis isomeric isoxazoles have been realized. catalysis with Cu(II) salt provides 3,4-disubsituted via [3 + 2] cycloaddition. On other hand, Ag(I) identical substrates leads to reversed C3 C4 substitution based on a key [2 1]

Language: Английский

Citations

41

Expeditious Synthesis of Spiroindoline Derivatives via Tandem C(sp2)–H and C(sp3)–H Bond Functionalization of N-Methyl-N-nitrosoanilines DOI

Wang Kelin,

Yu‐Qian Sun, Bin Li

et al.

Organic Letters, Journal Year: 2024, Volume and Issue: 26(15), P. 3091 - 3096

Published: April 3, 2024

Presented herein is a novel synthesis of pharmaceutically privileged spiroindoline derivatives via cascade reactions N-methyl-N-nitrosoanilines with diazo homophthalimides. A group mechanistic studies disclosed that the formation product involves an unusual reaction mode N-methyl-N-nitrosoaniline featuring initial C(sp2)–H bond activation/alkylation followed by C(sp3)–H activation/spiroannulation. To our knowledge, this first example in which acts as C3N1 synthon to accomplish formal [4+1] spiroannulation participation N-methyl unit rather than previously reported C2N1 undergo [3+2] annulation without unit. In general, newly developed synthetic protocol features simple and readily accessible starting materials, valuable products, unique mechanism, high efficiency atom-economy, excellent compatibility diverse functional groups, ready scalability.

Language: Английский

Citations

17

Synthesis of homophthalimide spironaphthalenones through [5 + 1] spiroannulation of aryl/alkenyl enaminones with diazo homophthalimides DOI

Chun Xia Yang,

Xinying Zhang, Xuesen Fan

et al.

Organic Chemistry Frontiers, Journal Year: 2023, Volume and Issue: 10(17), P. 4282 - 4288

Published: Jan. 1, 2023

Presented herein is a novel synthesis of homophthalimide spironaphthalenones from the cascade reaction enaminones with diazo homophthalimides.

Language: Английский

Citations

21

Recent Advances in N-O Bond Cleavage of Oximes and Hydroxylamines to Construct N-Heterocycle DOI Creative Commons
Huimin Jiang, Yilin Zhao, Qing Sun

et al.

Molecules, Journal Year: 2023, Volume and Issue: 28(4), P. 1775 - 1775

Published: Feb. 13, 2023

Oximes and hydroxylamines are a very important class of skeletons that not only widely exist in natural products drug molecules, but also synthon, which have been used industrial production. Due to weak N-O σ bonds oximes hydroxylamines, they can be easily transformed into other functional groups by bond cleavage. Therefore, the synthesis N-heterocycle using as nitrogen sources has attracted wide attention. Recent advances for through transition-metal-catalyzed radical-mediated cyclization classified type rings summarized. In this paper, recent cleavage reviewed. We hope review provides new perspective on field, reference develop environmentally friendly sustainable methods.

Language: Английский

Citations

18

Asymmetric catalysis with chiral cyclopentadienyl complexes to access privileged scaffolds DOI
Caitlin Davies, Saad Shaaban, Herbert Waldmann

et al.

Trends in Chemistry, Journal Year: 2022, Volume and Issue: 4(4), P. 318 - 330

Published: Feb. 5, 2022

Language: Английский

Citations

27

Catalytic Stereoselective Multicomponent Reactions for the Synthesis of Spiro Derivatives: Recent Progress DOI

Divyang M. Patel,

Paras J. Patel,

Hitendra M. Patel

et al.

European Journal of Organic Chemistry, Journal Year: 2022, Volume and Issue: 2022(46)

Published: Nov. 16, 2022

Abstract Spiro derivatives are important scaffolding substances found in many natural products and pharmaceuticals. In the last decade, numerous new approaches based on multicomponent reactions have been explored for selective efficient development of spiro using various organocatalytic transition metal‐based catalytic systems. This Review discusses pioneering advances field stereoselective preparation derivatives. These include Michael cascade cyclization reactions, cycloadditions, diastereoselective miscellaneous synthesis spiro‐hetero/carbocycles. Advances decade made it possible to synthesize compounds with good excellent stereoselectivity under appropriate reaction conditions. However, achieving high regioselectivity several described remains a challenge. Organocatalysts transition‐metal‐based catalysts play crucial role this milestone. Proposed mechanisms supporting evidence highlighted Review. The progress is immense. expected that synthetic methods will soon be developed can widely used spiro‐heterocycles/carbocycles.

Language: Английский

Citations

20

A Stereodivergent–Convergent Chiral Induction Mode in Atroposelective Access to Biaryls via Rhodium-Catalyzed C–H Bond Activation DOI
Panjie Hu, Bingxian Liu, Fen Wang

et al.

ACS Catalysis, Journal Year: 2022, Volume and Issue: 12(22), P. 13884 - 13896

Published: Oct. 27, 2022

Understanding the reaction mechanisms, particularly chiral induction mode, is critical for development of new asymmetric catalytic reactions. Rhodium(III)-catalyzed C–H activation en route to atroposelective [4 + 2] annulative coupling with α-diazo β-ketoesters has been realized, affording axially phenanthrenes in good excellent enantioselectivity. A combination experimental and computational studies revealed a nontraditional stereodivergent–convergent mode. The proceeded rhodafluorene intermediate, followed by competitive, constructive, stereodivergent migratory insertions two Rh–C(aryl) bonds into carbene species give β-ketoester intermediates. Then, other bond migratorily inserts ketone carbonyl group. Following this stereodetermining insertion, an ester-chelated rhodium(III) alkoxide bearing poorly controlled centers well-controlled C(sp2)–C(sp3) axis generated. final product delivered via stereoconvergent elimination retention axial chirality loss central chirality.

Language: Английский

Citations

18