MNPs@Cu-catalyzed synthesis of 2-amino-3-cyano-pyrano[3,2-c] chromen-5(4H)-one (4) derivatives^a.

Entry	Product	RCHO (2)	Product	Time (min)	Yield (%)b	MP (obsd) (°C)	MP (lit.) (°C)
1	4a			12	91	258–260	256–25817
2	4b			12	92	260–263	260–26219
3	4c			8	94	249–251	250–25219
4	4d			8	94	243–245	244–24618
5	4e			8	95	262–264	263–26548
6	4f			8	95	259–261	260–26217
7	4g			15	92	233–235	236–23853
8	4h			20	90	240–243	242–24446
9	4i			15	93	222–224	221–22318
10	4j			20	90	226–229	228–23017
11	4k			15	92	256–259	253–25447
12	4l			15	90	261–264	260–26217
13	4m			15	90	250–252	252–25417
14	4n			15	95	258–260	259–26142
15	4o			20	89	261–264	265–26717

^aReaction conditions: 4-hydroxycoumarin (1 mmol), aldehyde (1 mmol), malononitrile (1.1 mmol), MNPs@Cu (10 mg).