Highly Efficient Synthesis of 1H-Indazole-3-carboxylic Acid Derivatives via Diazotization Reaction DOI Open Access
Changming Xu, Jincheng Huang

Chinese Journal of Organic Chemistry, Journal Year: 2021, Volume and Issue: 41(8), P. 3256 - 3256

Published: Jan. 1, 2021

Direct conversion of ortho-aminobenzacetamides and ortho-aminobenzacetates to the corresponding 1H-indazole-3-carboxylic acid derivatives under action diazotization reagents was reported.This method features operational simplicity, mild reaction conditions, rapid rates, high yields, wide substrate scope, offering an efficient concise route synthesis derivatives.The drugs granisetron lonidamine were synthesized successfully using this protocol with 46% 60% total respectively.Preliminary mechanistic study suggests that diazonium salt is a key intermediate.

Language: Английский

Synthesis of functionalized spiro[indanone-benzazepine] scaffolds via [4 + 3] annulation reaction of N-(o-chloromethyl)aryl amides with ninhydrin-derived Morita−Baylis−Hillman carbonates DOI Open Access
Kai‐Kai Wang, Junwei Ye,

Jun Jia

et al.

Tetrahedron, Journal Year: 2023, Volume and Issue: 150, P. 133772 - 133772

Published: Dec. 1, 2023

Language: Английский

Citations

4
Strategy to Construct Polycyclic Scaffolds via Formal Aza‐Diels‐Alder Reaction of Dihydro‐β‐Carboline with Heterodiene Precursor DOI
Xiaoke Zhang,

Jinding Wei,

Minghong Zhu

et al.

Advanced Synthesis & Catalysis, Journal Year: 2023, Volume and Issue: 365(22), P. 3996 - 4001

Published: July 8, 2023

Abstract The formal aza‐Diels‐Alder reaction of dihydro‐ β ‐carboline with heterodiene mediated by caesium carbonate has been described. This pathway provided a mild approach to functionalized polycyclic frameworks in 41%–91% yields.

Language: Английский

Citations

3
Strategy to Construct 1,2,3‐Triazoles by K2CO3‐Mediated [4+1] Annulation Reactions of N‐Acetyl Hydrazones with Bifunctional Amino Reagents DOI
Xiaoke Zhang,

Yang Pan,

Haibo Wang

et al.

Advanced Synthesis & Catalysis, Journal Year: 2020, Volume and Issue: 363(2), P. 459 - 463

Published: Dec. 1, 2020

Abstract K 2 CO 3 ‐mediated [4+1] annulation reactions of N ‐acetyl hydrazones with bifunctional amino reagents are described, which provide an environmental‐friendly strategy to construct 1,2,3‐triazoles that does not employ metals, azides, organocatalysis, or oxidants. A series substituted 1,2,3‐triazole derivatives was prepared good yields. magnified image

Language: Английский

Citations

6
Synthesis of Functionalized Tetrahydroquinoline Containing Indole Scaffold via Chemoselective Annulation of Aza-ortho-quinone Methide Precursor DOI Creative Commons
Xiaoke Zhang,

Qianlu Xing,

Zhengxing Gou

et al.

ACS Omega, Journal Year: 2023, Volume and Issue: 8(25), P. 22352 - 22360

Published: June 13, 2023

The chemoselective annulation of aza-ortho-quinone methide generated by in situ o-chloromethyl sulfonamide has been achieved with bifunctional acyclic olefin. This efficient approach provides access to the diastereoselective synthesis functionalized tetrahydroquinoline derivatives containing indole scaffolds through inverse-electron-demand aza-Diels-Alder reaction under mild conditions excellent results (up 93% yield, > 20:1 dr). Moreover, this article realized cyclization α-halogeno hydrazone electron-deficient alkene affording tetrahydropyridazine derivatives, which had never reported.

Language: Английский

Citations

2
[4+2]-Cycloaddition Reactions of Aza-o-quinone Methides with Fulvenes: Construction of Tetrahydroquinoline Derivatives DOI
Gang Wang, Zhao‐Lin He,

Hang Cheng

et al.

Synlett, Journal Year: 2022, Volume and Issue: 33(08), P. 795 - 799

Published: March 13, 2022

Abstract An efficient [4+2] cycloaddition reaction of fulvenes with aza-o-quinone methides, generated in situ from N-(o-chloromethyl)aryl sulfonamides the assistance a base, has been developed to afford series tetrahydroquinoline derivatives. The tolerates wide range methides and bearing four- seven-membered rings corresponding tetrahydroquinolines moderate good yields. Based on literature analysis, plausible mechanism for this is proposed.

Language: Английский

Citations

4
Chemodivergent Synthesis of Aza-Heterocycles with a Quarternary Carbon Center via [4 + 1] Annulation between Azoalkenes and α-Bromo Carbonyl Compounds DOI Creative Commons
Xiaoke Zhang, Haibo Wang,

Ziwei Li

et al.

ACS Omega, Journal Year: 2022, Volume and Issue: 7(45), P. 40963 - 40972

Published: Nov. 1, 2022

An efficient [4 + 1] annulation reaction between in situ generated azoalkene intermediates and α-bromocarbonyls has been established. A series of skeletally diverse aza-heterocycles with a functionalized quaternary center were obtained up to 89% yield under mild conditions.

Language: Английский

Citations

4
Investigations on Superbase Mediated Reactivity of N‐Tosylhydrazones with Aza‐ortho‐Quinone Methide Precursors DOI

P Rahul,

T. K. Arunkumar,

Seena Sebastian

et al.

European Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 27(18)

Published: March 16, 2024

Abstract We have encountered a superbase‐mediated chemoselective reaction of N ‐tosylhydrazones with aza‐ ortho ‐quinone methide precursors. When tosylhydrazone was treated ‐aminobenzyl alcohol in super basic conditions (KOH+DMSO), we observed the formation 2‐substituted quinoline. The found to be general, and by this method, mono‐, di‐ tri‐substituted quinolines could made. prove experimentally theoretically that proceeded via an azine from decomposition ‐tosylhydrazones. Finally, ‐(2‐(chloromethyl)phenyl)‐4‐methylbenzenesulfonamide (aza‐ precursor) under afforded hydrazine substituted sulfonamides.

Language: Английский

Citations

0
One Pot Tandem P-Michael Addition/SN2/Intramolecular Wittig Reaction of aza-o-Quinone Methides: Construction of 2,3-Disubstituted Dihydroquinoline Derivatives DOI

Y. C. Liu,

Hang Cheng,

Zhao‐Lin He

et al.

Chinese Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 44(7), P. 2241 - 2241

Published: Jan. 1, 2024

Language: Английский

Citations

0
Dearomatization of Halonaphthols via an Intermolecular [4＋1] Spiroannulation with in situ Formed Aza-ortho-quinone Methides DOI Open Access

Junxiu Liang,

Yazhou Liu, Amu Wang

et al.

Chinese Journal of Organic Chemistry, Journal Year: 2023, Volume and Issue: 43(11), P. 3888 - 3888

Published: Jan. 1, 2023

A base promoted dearomatization strategy for [4＋1] spiroannulation of halonaphthols with N-(o-chloromethyl) aryl amides is reported, which used to efficiently synthesize azaspirocycles.A range azaspirocycles were obtained in satisfactory excellent yield high diastereoselectivity under mild conditions.Variety functional groups including aldehyde and free hydroxyl group, different N-protecting groups, such as Bz Ts are compatibility.The transformation the product a possible mechanism also provided.

Language: Английский

Citations

1
A Novel Method to Construct 2-Aminobenzofurans via [4 + 1] Cycloaddition Reaction of In Situ Generated Ortho-Quinone Methides with Isocyanides DOI Creative Commons

Huaxin Lin,

Senling Tang,

Yang Pan

et al.

Molecules, Journal Year: 2022, Volume and Issue: 27(23), P. 8538 - 8538

Published: Dec. 4, 2022

A new approach for the synthesis of 2-aminobenzofurans has been described via Sc(OTf)3 mediated formal cycloaddition isocyanides with in situ generated ortho-quinone methides (o-QMs) from o-hydroxybenzhydryl alcohol. Notably, as a class readily available and highly active intermediates, o-QMs were first used construction benzofurans. This [4 + 1] reaction provides straightforward efficient methodology scaffold good yield (up to 93% yield) under mild conditions.

Language: Английский

Citations

2