One-pot multi-component synthesis of 2-Amino-4H-chromenes catalyzed by a fiber super base under mild conditions

Heterogeneous catalysis is a crucial component of green chemistry. In this study, a series of polyacrylonitrile fiber (PANF) catalysts, specifically PANF-TBDs, were developed by immobilizing the commonly utilized super organic base 1,5,7-triazabicyclo [4.4.0] dec-5-ene (TBD) onto commercially accessible PANF. This novel catalyst facilitates the effective and eco-friendly one-pot synthesis of 2-amino-4H-chromene. Moreover, an investigation into the impact of modification density on the catalytic efficacy of PANF-TBDs have been conducted. It was observed that PANF-TBD(2.0) with a higher TBD graft density can yield exceptional results, even surpassing 96 %, in a mere 30 min at a mild temperature 30 °C when utilizing water as a green and easily available solvent. Furthermore, the catalyst can be effortlessly isolated from the reaction system and displays notable reusability for a minimum of 10 cycles without show obvious decline in performance.