Catalyst-free one-pot synthesis of benzimidazoles from 1,2-diaminoarenes and alcohols

Reddy, Marri Mahender; Swamy, Peraka; Macharla, Arun Kumar; Mameda, Naresh; Kodumuri, Srujana; Narender, Nama

doi:10.1016/j.tetlet.2014.09.081

Cited by 23 publications

(16 citation statements)

References 41 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Benzimidazoles have been synthesized by a number of processes involving condensation of 1,2‐phenylenediamines with aldehydes, carboxylic acids, esters and amides in the presence of different oxidants and metal catalysts . Aromatic and long chain (≥C 3 ) alcohols easily get oxidized into corresponding carbonyls and utilized for different benzimidazoles synthesis using 1,2‐phenylenediamines under different catalytic conditions . Aliphatic alcohols such as ethanol/methanol are difficult to oxidize due to their higher oxidation potential than aromatic or long chain (≥C 3 ) alcohols under reported catalytic conditions.…”

Section: Methodsmentioning

confidence: 99%

Supported Rhodium (Rh@PS) Catalyzed Benzimidazoles Synthesis Using Ethanol/Methanol as C₂H₃/CH Source

Sharma

Yamini

et al. 2018

Adv Synth Catal

View full text Add to dashboard Cite

An effective and stable polystyrene supported rhodium (Rh@PS) nano-catalyst has been synthesized by following reduction-deposition approach and applied for the selective benzimidazoles synthesis from 1,2-phenylenediamines and ethanol/ methanol as C 2 H 3 /CH source. The ethanol/methanol in the presence of trace amounts of aerobic oxygen under Rh@PS catalysed condition, first participated in oxidation of alcohol followed by consecutive condensation, cyclization and hydrogen elimination reactions with 1,2-phenylenediamine gave the desired products in good yields. The Rh@PS catalyst in a single system performed both oxidation and reduction reactions in a selective/ specific manner and applied for large substrate scope. Easy recovery, handling, stability, recyclability of the catalyst and less chance of metal contamination with the products are the added advantages of the process.

show abstract

Section: Methodsmentioning

confidence: 99%

Supported Rhodium (Rh@PS) Catalyzed Benzimidazoles Synthesis Using Ethanol/Methanol as C₂H₃/CH Source

Sharma

Yamini

et al. 2018

Adv Synth Catal

View full text Add to dashboard Cite

show abstract

“…2‐(2‐Bromophenyl)‐1 H ‐benzo[ d ]imidazole (2a′): White solid (37 mg, 73 %). R f = 0.4 (hexane/ethyl acetate, 4:1).…”

Section: Methodsmentioning

confidence: 99%

An Intramolecular C(sp²)–H Amidation Using N‐Iodosuccinimide

2018

View full text Add to dashboard Cite

An N‐iodosuccinimide (NIS) mediated intramolecular dehydrogenative C(sp2)–H amidation is reported for easy and convenient access to 1,2‐disubstituted benzimidazoles. The nonprefunctionalized C(sp2)–H and N(sp3)–H bonds were directly coupled using NIS in trifluoroethanol, which proved to be mild alternative to strong oxidative iodine(III) reagents. The reaction worked at room temperature, under an air atmosphere, and in the absence of any base additive.

show abstract

“…Yield: 70%; colourless liquid; 1 H NMR (400 MHz, CDCl 3 ) δ (ppm) 7.69 (dd, J = 8.0Hz, 1.2 Hz, 1H), 7.30-7.40 (m, 4H), 7.33-7.27 (m, 1H), 7.16 (t, J = 7.2 Hz, 1H), 6.55 (d, J = 8.0 Hz, 1H), 6.46 (td, J = 7.8 Hz, 1.2 Hz, 1H), 4.64 (s, 1H), 4.41 (d, J = 5.6 Hz, 2H); 13 C NMR (100 MHz, CDCl 3 ) δ (ppm) 147.0, 138.9, 138.6, 129. 4, 128.7, 127.3, 127.1, 118.8, 110.9, 85.3, 48.3.…”

Section: N-benzyl-2-iodoaniline (1a)mentioning

confidence: 99%

Copper-Catalyzed Double C–N Bond Formation for the Synthesis of Diverse Benzimidazoles from N-Alkyl-2-iodoaniline and Sodium Azide

Chen

Liu

Cao

et al. 2016

Synlett

View full text Add to dashboard Cite

An efficient approach to the synthesis of benzimidazole derivatives has been achieved by copper-catalyzed double C-N bonds formation of N-alkyl-2-iodoaniline and sodium azide. The reaction was supposed to proceed through copper-catalyzed tandem reaction of S N Ar reaction, aerobic oxidation of C(sp 3 )-H bond and intramolecular C-N bond formation sequence. Structurally diverse 2-aryl, alkenyl and alkyl benzoimidazole derivatives were assembled by this methodology.

show abstract

Catalyst-free one-pot synthesis of benzimidazoles from 1,2-diaminoarenes and alcohols

Cited by 23 publications

References 41 publications

Supported Rhodium (Rh@PS) Catalyzed Benzimidazoles Synthesis Using Ethanol/Methanol as C₂H₃/CH Source

Supported Rhodium (Rh@PS) Catalyzed Benzimidazoles Synthesis Using Ethanol/Methanol as C₂H₃/CH Source

An Intramolecular C(sp²)–H Amidation Using N‐Iodosuccinimide

Copper-Catalyzed Double C–N Bond Formation for the Synthesis of Diverse Benzimidazoles from N-Alkyl-2-iodoaniline and Sodium Azide

Contact Info

Product

Resources

About

Catalyst-free one-pot synthesis of benzimidazoles from 1,2-diaminoarenes and alcohols

Cited by 23 publications

References 41 publications

Supported Rhodium (Rh@PS) Catalyzed Benzimidazoles Synthesis Using Ethanol/Methanol as C2H3/CH Source

Supported Rhodium (Rh@PS) Catalyzed Benzimidazoles Synthesis Using Ethanol/Methanol as C2H3/CH Source

An Intramolecular C(sp2)–H Amidation Using N‐Iodosuccinimide

Copper-Catalyzed Double C–N Bond Formation for the Synthesis of Diverse Benzimidazoles from N-Alkyl-2-iodoaniline and Sodium Azide

Contact Info

Product

Resources

About

Supported Rhodium (Rh@PS) Catalyzed Benzimidazoles Synthesis Using Ethanol/Methanol as C₂H₃/CH Source

Supported Rhodium (Rh@PS) Catalyzed Benzimidazoles Synthesis Using Ethanol/Methanol as C₂H₃/CH Source

An Intramolecular C(sp²)–H Amidation Using N‐Iodosuccinimide