L-(+)-Tryptophan methyl ester derived polymeric microbeads as an efficient heterogeneous catalyst for green synthesis of 2-amino-4-(nitromethyl)-4H-chromene-3- carbonitriles

The cross-linked microbeads with average diameter of 106-300 μm, [poly(EGDMA-MATrp)], were obtained by copolymerization reaction N-methacryloyl-L-(+)-tryptophan methyl ester (MATrp) ethylene glycol dimethacrylate (EGDMA) and successfully applied as a heterogeneous catalyst in conjugate addition nitromethane to substituted 2-iminochromenes aqueous media. A variety 2-amino-4-(nitromethyl)-4H-chromene-3-carbonitriles has been synthesized good yields. Polymeric very durable reused 5 times without significant loss activity. DFT calculations experimental results revealed the role π-π interactions well hydrogen bonding mechanism.