Natural silk as a biodegradable, biocompatible, renewable, green and abundant biomaterial was used as a support for chemical immobilization of a water‐soluble manganese(II) complex with a phthalocyanine ligand possessing covalent binding ability. The prepared manganese(II) tetrasulfophthalocyanine complex supported on natural silk revealed efficient catalytic activity and reusability for the synthesis of benzoxazepine derivatives in water at room temperature.

Natural wool sulfonic acid (wool-SO 3 H) and wool-supported Fe 3 O 4 nanoparticles (nano-Fe 3 O 4 @wool) with highly loaded Fe 3 O 4 nanoparticles were simply synthesized and characterized by flame atomic absorption spectroscopy, X-ray diffraction, thermogravimetric analysis, and scanning electron microscopy. The successful synthesis of 3,4-dihydroquinoxalin-2-amine, 1,6-dihydropyrazine-2,3-dicarbonitrile, (cyanophenylamino)acetamide, tetrahydro-1H-1,5-benzodiazepine-2-carboxamide, and 4,5,6,7-tetrahydro-1H-1,4-diazepine-5-carboxamide derivatives shows that wool-SO 3 H and Fe 3 O 4 @wool nanocomposite have high catalytic activity and can be repetitively used as two biodegradable catalysts. Graphical abstract

A one-pot three-component cascade reaction for the green synthesis of a new class of 2-amino-5,8-dihydro-3H-pyrido[2,3-d]pyrimidin-4-ones was developed from the condensation of aromatic aldehydes with 2,6-diaminopyrimidin-4(3H)-one and acetophenone derivatives or various cyclic ketones in the presence of a catalytic amount of sodium carbonate in a mixture of water and ethanol at 60  [Formula: see text]. This reaction led to the construction of two carbon-carbon bonds and one carbon-nitrogen bond in a single synthetic step.