An efficient, sustainable approach to the chemo and regioselective synthesis of novel spiroindenoquinoxaline grafted piperidone hybrid heterocycles

Abstract

An efficient, eco-friendly and sustainable approach for the synthesis of novel spiroindeno[1,2-b]quinoxaline-3-phenylspiro[4,3″]benzylidenepiperidone ring system has been developed by a one-pot four component [3 + 2] cycloaddition strategy. The 1,3-dipole generated in situ from quinoxalinone and l-phenylalanine reacts with the highly functionalized dipolarophiles, bisarylidene piperidones affording spirohybrid heterocycles in good yields. The unexplored novel class of dispirohybrid heterocycles obtained possess three CN and two CC bonds with four adjacent stereogenic carbons, out of which two is spirocarbons. The structure of compounds was elucidated using 1H, 13C and mass spectroscopic studies.