Synthesis of 2-substituted-benzothiazoles by palladium-catalyzed intramolecular cyclization of o-bromophenylthioureas and o-bromophenylthioamides

Benedı́, Carolina; Bravo, Fernando; Uriz, Pedro; Fernández, Elena; Claver, Carmen; Castillón, Sergio

doi:10.1016/s0040-4039(03)01469-2

Cited by 171 publications

(61 citation statements)

References 41 publications

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“…(1) in Scheme 1]. [6] For example, Castillón and co-workers firstly reported a procedure for the synthesis of benzothiazoles using obromoarylthioamide substrates and the 2 catalytic system. Very recently, Wu and co-workers described a practical copper-catalyzed tandem reaction between 2-halobenzenamines and isothiocyanates to prepare 2-aminobenzothiozoles.…”

Section: Iron-catalyzed Tandem Reactions Of 2-halobenzenamines With Imentioning

confidence: 99%

Iron‐Catalyzed Tandem Reactions of 2‐Halobenzenamines with Isothiocyanates Leading to 2‐Aminobenzothiazoles

et al. 2009

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Section: Iron-catalyzed Tandem Reactions Of 2-halobenzenamines With Imentioning

confidence: 99%

Iron‐Catalyzed Tandem Reactions of 2‐Halobenzenamines with Isothiocyanates Leading to 2‐Aminobenzothiazoles

et al. 2009

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“…The palladium-or copper-catalyzed cyclization of N-(2-halophenyl)-thiobenzamides provides another route to benzothiazoles. [49][50][51][52] It is necessary to prefunctionalize starting materials in these reactions, which significantly limits the utility and applicability of this approach. To test the feasibility of C-S bond formation via C-H functionalization, we chose the reaction of thiobenzanilide (15a), which would result in a new approach a) The reaction mixture was first stirred at 100°C for 1 h and then stirred at 120°C for 10 h. for the construction of a benzothiazole nucleus.…”

Section: -46)mentioning

confidence: 99%

Synthesis of Heterocyclic Compounds through Palladium-Catalyzed C–H Cyclization Processes

Inamoto

2013

CHEMICAL & PHARMACEUTICAL BULLETIN

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Herein, we describe our development of synthetic methods for heterocyclic compounds based on the palladium-catalyzed carbon-hydrogen bond (C-H) functionalization/intramolecular carbon-heteroatom (nitrogen or sulfur) bond formation process. By this C-H cyclization method, we efficiently prepared various N-heterocycles, including indazoles, indoles, and 2-quinolinones, as well as S-heterocycles such as benzothiazoles and benzo[b]thiophenes. Yields are typically good to high and good functional-group tolerance is observed for each process, thereby indicating that the method provides a novel, highly applicable synthetic route to the abovementioned biologically important heterocyclic frameworks. As an application of this approach, an auto-tandem-type, one-pot process involving the oxidative Heck reaction and subsequent C-H cyclization using cinnamamides and arylboronic acids as starting materials in the presence of a palladium catalyst was also developed for the rapid construction of the 2-quinolinone nucleus.

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“…Castillon et al reported Pd-catalyzed cyclization of 2-bromophenylthioamides using Pd 2 (dba) 3 /(2-biphenyl)P(t-Bu) 2 catalytic system (Scheme 5) [19]. …”

Section: Introductionmentioning

confidence: 99%

Mechanistic Study on the Formation of Compounds from Thioureas

Laitonjam¹,

Nahakpam²

2018

Density Functional Calculations - Recent Progresses of Theory and Application

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Formation of 2-(N-arylamino)benzothiazole takes place, when N,N 0 -diphenylthioureas are treated with polymer-supported tribromide or with iodine-alumina as catalyst under solvent free conditions. However, when N-substituted-N 0 -benzoylthioureas are treated with polymer-supported tribromide or with iodine-alumina as catalyst either under various conditions or under solvent free conditions, decomposition takes place to give the respective benzamides and thiobenzamides. Mechanistic study of the formation of these compounds is studied using DFT calculations. It is found that electron donating group at the para-position of the aryl group of benzoylthiourea favors the formation of benzamide whereas the presence of electron withdrawing group at para-position of the aryl group of benzoylthiourea, formation of thiobenzamide takes place. When the catalyst is changed to diacetoxyiodobenzene (DIB) under similar reaction conditions, benzoxazole amides are formed; expected benzothiazoles or the decomposition products are not obtained. Mechanistic study of the reaction using DFT calculation again shows that the reaction followed through carbodiimide intermediate undergoes the formation of C-O bond in benzoxazole moiety, instead of the expected C-S bond formation of benzothiazole moiety via a sequential acylation and deacylation process.

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Synthesis of 2-substituted-benzothiazoles by palladium-catalyzed intramolecular cyclization of o-bromophenylthioureas and o-bromophenylthioamides

Cited by 171 publications

References 41 publications

Iron‐Catalyzed Tandem Reactions of 2‐Halobenzenamines with Isothiocyanates Leading to 2‐Aminobenzothiazoles

Iron‐Catalyzed Tandem Reactions of 2‐Halobenzenamines with Isothiocyanates Leading to 2‐Aminobenzothiazoles

Synthesis of Heterocyclic Compounds through Palladium-Catalyzed C–H Cyclization Processes

Mechanistic Study on the Formation of Compounds from Thioureas

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