01795nas a2200193   4500008004100000022001400041245016600055210006900221260000800290300001400298490000700312520105700319100002101376700001601397700002001413700001801433700001901451856013101470       2025                        eng d  a1144-054600aDABCO dicationic ionic solid supported polymer (DDIS@PS) mediated synthesis of diverse 2-amino-4H-chromenes and xanthenes: a cascade Knoevenagel-Michael approach0 aDABCO dicationic ionic solid supported polymer DDISPS mediated s  cFEB  a3644-36530 v493 a<p>
	This work documented the synthesis of diverse bioactive polysubstituted 2-amino-4H-chromenes using a DABCO dicationic ionic solid (DDIS) supported on Merrifield resin (DDIS@PS) as a catalyst. The catalyst is characterized by FT-IR, SEM-EDX, and TGA analysis. The resulting PS contains supported DABCO units with free tertiary nitrogen functionality on their external surface. The catalyst effectively catalyzed cascade Knoevenagel-Michael addition reactions of various aldehydes and active methylene compounds (malononitrile and phenyl sulfonyl acetonitrile) with dimedone, yielding good to excellent results in water or ethanol at room temperature or 78 degrees C. The time required for the reaction of phenyl sulfonyl malononitrile is comparatively very high compared to malononitrile. The synthesis of bis-dimedone derivatives and 1,8-dioxo-octahydro-xanthenes was also achieved in both solvents at RT and 78 degrees C, with high yields. The catalyst demonstrated greater efficiency and maintained its activity over at least five cycles.</p>
1 aRajmane, Archana1 aPatil, Nita1 aPatil, Anuradha1 aKamble, Sumit1 aKumbhar, Arjun  uhttps://library.ncl.res.in/content/dabco-dicationic-ionic-solid-supported-polymer-ddisps-mediated-synthesis-diverse-2-amino-4h