Cu(3)(BTC)(2) as a viable heterogeneous solid catalyst for Friedel-Crafts alkylation of indoles with nitroalkenes.
In the present work, Friedel-Crafts alkylation reaction of indole with β-nitrostyrene is examined using a readily available copper based metal-organic frameworks (MOFs) namely, Cu3(BTC)2(BTC: 1,3,5-benzenetricarboxylic acid) as solid catalyst under mild reaction conditions. Among the various catalysts screened for this reaction, Cu3(BTC)2exhibits higher activity under the optimized reaction conditions. Besides the absence of leaching of active sites, it is also observed that the catalyst can be reused for four cycles with a minimal decrease in its activity. Cu3(BTC)2is used as a catalyst to synthesise a series of heterocyclic compounds with different indole and β-nitrostyrene derivatives in moderate to high yields. The present catalytic system shows comparable activity against to recent reports but the advantage of Cu3(BTC)2is that it does not require any post-functionalization and above all it can be readily synthesised, thus contributing to the synthesis of heterocyclic compounds with high biological interest.
School of Chemistry, Madurai Kamaraj University, Madurai 21, India.
Anbu
A
Nagaraj
School of Chemistry, Madurai Kamaraj University, Madurai 21, India. Electronic address: admguru@gmail.com.
Dhakshinamoorthy
D
Amarajothi
D000475:Alkenes / Q000737:chemistry*; D000478:Alkylation; D002384:Catalysis; D003300:Copper / Q000737:chemistry*; D007211:Indoles / Q000737:chemistry*; D013343:Styrenes / Q000737:chemistry*
D000475:Alkenes; D007211:Indoles; D013343:Styrenes; C011955:beta-nitrostyrene; D003300:Copper
Friedel-Crafts alkylation; Green chemistry; HKUST-1; Heterogeneous catalysis; Metal organic frameworks