Silica‐supported Cu(II)–quinoline complex: Efficient and recyclable nanocatalyst for one‐pot synthesis of benzimidazolquinoline derivatives and 2H‐indazoles

Abstract

The synthesis, characterization and catalytic activity of a Cu(II) complex derived from 2‐oxoquinoline‐3‐carbaldehyde Schiff base supported on amino‐functionalized silica are reported. 3‐(1H‐Benzo[d]imidazol‐2‐yl)quinolines containing piperidine, morpholine and phenylpiperazine skeletons at the C‐2 position were formed in good to excellent yields via the one‐pot reaction of 2‐chloroquinoline‐3‐carbaldehyde, benzene‐1,2‐diamines and secondary amines in the presence of the nanocatalyst under mild conditions. Moreover, the nanocatalyst was found to be recyclable for up to seven runs without significant loss of activity. Also, a series of 2H‐indazoles were synthesized by the catalytic condensation of 2‐bromobenzaldehyde, sodium azide and primary amines.

Preparation, Characterization and Application of Copper Schiff base Complex Supported on MCM‐41 as a Recyclable Catalyst for the Ullmann‐type N‐arylation Reaction

“…A plausible mechanism for the Cu@SB@MCM‐41‐catalyzed C−N bond formation reaction, based on previous reports, is proposed in Scheme . First, in the presence of base, N‐source compound can be coordinated to the metal center by its electron pair.…”

Copper‐Catalysed Multicomponent Syntheses of Heterocycles

“…Sharghi and co‐workers developed an efficient, versatile and highly reusable nanocatalyst, supported benzimidazole‐salen Cu(II) complex (BS‐Cu(II)@SiO 2 ) (Figure ) for the synthesis of triazole‐benzimidazole hybrid molecules via a one‐pot four‐component C−H bond activation/[3+2] cycloaddition and condensation/cyclisation/aromatization sequence . Optimized synthesis of 1,4‐disubstituted‐1,2,3‐triazole‐1 H ‐benzo[ d ]imidazole hybrids from benzyl halides, 4‐(prop‐2‐yn‐1‐yloxy)benzaldehyde, sodium azide and o ‐phenylenediamines involves the use of 5.0 mol% of the nanocatalyst in 10 ml of H 2 O/C 2 H 5 OH (9 : 1 v/v) at room temperature for 6 h. The synthesis of these hybrid molecules was also achieved with epoxides and phenylboronic acid instead of benzylhalides which afforded good yields of the corresponding desired product.…”

An Overview of Recent Advances in the Applications of Click Chemistry in the Synthesis of Bioconjugates with Anticancer Activities

“…The copper‐catalyzed 1,3‐dipolar cycloaddition of an azide to a terminal alkyne is an easy route to tolerate a wide diversity of functional groups. The CuAAC reaction gives excellent yields and has been applied in organic synthesis, materials science, catalysis, and the biochemistry …”