N-Bromosuccinimide (NBS)-Catalyzed C–H Bond Functionalization: An Annulation of Alkynes with Electron Withdrawing Group (EWG)-Substituted Acetyl Indoles for the Synthesis of Carbazoles DOI
Han Wang, Zhen Wang, Yilong Wang

и другие.

Organic Letters, Год журнала: 2017, Номер 19(22), С. 6140 - 6143

Опубликована: Ноя. 2, 2017

An N-bromosuccinimide-catalyzed intermolecular annulation of acetyl indoles with alkynes was developed, allowing for regioselective formation valuable carbazoles through direct C-H bond functionalization. The readily available catalyst, wide substrate scope, gram scale synthesis, and mild conditions make this method practical. Mechanistic investigations indicate that the bromination indole takes place to generate a bromide intermediate, followed by coupling an alkyne intramolecular cycloaromatization furnish carbazole products.

Язык: Английский

Assembly of 2-Arylbenzothiazoles through Three-Component Oxidative Annulation under Transition-Metal-Free Conditions DOI

Xingzong Che,

Jingjing Jiang, Fuhong Xiao

и другие.

Organic Letters, Год журнала: 2017, Номер 19(17), С. 4576 - 4579

Опубликована: Авг. 17, 2017

Highly efficient methods for the synthesis of 2-arylbenzothiazoles and 2-arylnaphtho[2,1-d]thiazoles have been developed. Readily available aromatic amines, benzaldehydes, elemental sulfur were directly assembled through oxidative annulation C–H functionalization under transition-metal-free conditions, where DMSO or oxygen served as oxidant. NH4I KI catalyst was found to be effective promote transformations give products in good excellent yields with wide functional group tolerance.

Язык: Английский

Процитировано

101

Electrooxidative dearomatization of biaryls: synthesis of tri- and difluoromethylated spiro[5.5]trienones DOI Creative Commons
Yan Zhang,

Chanchan Ma,

Julia Struwe

и другие.

Chemical Science, Год журнала: 2021, Номер 12(29), С. 10092 - 10096

Опубликована: Янв. 1, 2021

Radical spirocyclization via dearomatization has emerged as an attractive strategy for the rapid synthesis of structurally diverse spiro molecules. We report use electrochemistry to perform oxidative biaryls leading tri- and difluoromethylated spiro[5.5]trienones in a user friendly undivided cell set-up constant current mode. The catalyst- chemical oxidant-free procedure features ample scope, employs electricity green sole oxidant.

Язык: Английский

Процитировано

86

Recent advances in the synthesis of carbazoles from indoles DOI

Trapti Aggarwal,

Sushmita Sushmita,

Akhilesh K. Verma

и другие.

Organic & Biomolecular Chemistry, Год журнала: 2019, Номер 17(36), С. 8330 - 8342

Опубликована: Янв. 1, 2019

Synthesis of carbazoles using indoles as precursors through CH activation/annulation.

Язык: Английский

Процитировано

80

Benzannulation strategies for the synthesis of carbazoles, indolocarbazoles, benzocarbazoles, and carbolines DOI
Ankush Banerjee,

Samrat Kundu,

Arya Bhattacharyya

и другие.

Organic Chemistry Frontiers, Год журнала: 2021, Номер 8(11), С. 2710 - 2771

Опубликована: Янв. 1, 2021

This review presents a critical and authoritative analysis of several exciting benzannulation approaches developed in the past decade for construction carbazoles, indolocarbazoles, benzocarbazoles, carbolines.

Язык: Английский

Процитировано

71

Three-component synthesis of 2-heteroaryl-benzothiazoles under metal-free conditions DOI
Guozheng Li, Hao Xie, Jinjin Chen

и другие.

Green Chemistry, Год журнала: 2017, Номер 19(17), С. 4043 - 4047

Опубликована: Янв. 1, 2017

2-Heteroaryl-benzothiazole derivatives were selectively prepared from anilines, 2-methylquinolines and elemental sulfur under metal-free conditions.

Язык: Английский

Процитировано

80

One-Pot Cascade Synthesis of Substituted Carbazoles from Indoles, Ketones, and Alkenes Using Oxygen as the Oxidant DOI
Shanping Chen, Yuxia Li, Penghui Ni

и другие.

The Journal of Organic Chemistry, Год журнала: 2017, Номер 82(6), С. 2935 - 2942

Опубликована: Фев. 21, 2017

An efficient one-pot two-step indole-to-carbazole strategy has been developed. This transition metal-free methodology uses oxygen as the sole oxidant and starts from cheap readily available indoles, ketones, alkenes. The present protocol efficiently enables assembly of a diverse array substituted carbazole products with good regioselectivity broad tolerance functional groups.

Язык: Английский

Процитировано

69

Gold-Catalyzed Synthesis of 1-(Indol-3-yl)carbazoles: Selective 1,2-Alkyl vs 1,2-Vinyl Migration DOI

Anisley Suárez,

Samuel Suárez‐Pantiga, Olalla Nieto Faza

и другие.

Organic Letters, Год журнала: 2017, Номер 19(19), С. 5074 - 5077

Опубликована: Сен. 18, 2017

Gold(III)-catalyzed cycloisomerization of α-bis(indol-3-yl)methyl alkynols selectively affords 1-(indol-3-yl)carbazoles, in a transformation that takes place through selective 1,2-alkyl vs 1,2-vinyl migration step the vinyl-gold intermediate generated from initial 5-endo-spirocyclization. The reaction proceeds well with either tertiary or secondary starting as wide variety alkyne substituents. key role other indol-3-yl substituent for unexpected selectivity 1,2 rearrangement has also been supported by DFT calculations reveal low barrier, two-step mechanism alkyl path where second indole significantly stabilizes carbocationic intermediate.

Язык: Английский

Процитировано

64

Transition-Metal-Free N–O Reduction of Oximes: A Modular Synthesis of Fluorinated Pyridines DOI
Huawen Huang, Jinhui Cai, Hao Xie

и другие.

Organic Letters, Год журнала: 2017, Номер 19(14), С. 3743 - 3746

Опубликована: Июнь 29, 2017

An NH4I-based reductive system has been explored to promote the oxime N–O bond cleavage and thereby enable a modular synthesis of broad range pharmacologically significant fluorinated pyridines. Compared with traditional condensation methods for pyridine assembly, this protocol was found be highly regio- chemoselective presented functional group tolerance.

Язык: Английский

Процитировано

63

A General Carbazole Synthesis via Stitching of Indole–Ynones with Nitromethanes: Application to Total Synthesis of Carbazomycin A, Calothrixin B, and Staurosporinone DOI
Shweta Singh, Ramesh Samineni, Srihari Pabbaraja

и другие.

Organic Letters, Год журнала: 2019, Номер 21(9), С. 3372 - 3376

Опубликована: Апрель 23, 2019

A new, one-pot domino benzannulation reaction between indole-3-ynones and various nitromethane derivatives has been explored for a general entry to diversely functionalized carbazole frameworks (28 examples). The scope of this new extended variants like 2-chloroindole-3-ynones eventuate in chemo-differentiated 1,2,3,4-tetrasubstituted carbazoles with retention the nitro group. efficacy strategy demonstrated through concise total synthesis natural products, viz. carbazomycin A, calothrixin B, staurosporinone (K252c).

Язык: Английский

Процитировано

59

Rh(III)-Catalyzed [5 + 1] Annulation of Indole-enaminones with Diazo Compounds To Form Highly Functionalized Carbazoles DOI
Zhidong Jiang, Jianhui Zhou, Haoran Zhu

и другие.

Organic Letters, Год журнала: 2021, Номер 23(11), С. 4406 - 4410

Опубликована: Май 21, 2021

A novel Rh(III)-catalyzed C–H activation/annulation cascade of indole-enaminones with diazo compounds was reported to construct diversely functionalized carbazole frameworks. The most notable characteristic is that this transformation could smoothly furnish a [5 + 1] cyclization product good excellent yields (up 95%), accompanied by the thorough removal acetyl and N,N-dimethyl groups two substrates from target products, rather than normally expected [4 2] products.

Язык: Английский

Процитировано

50