Magnetic nanoparticles/functionalized magnetic nanoparticles-catalyzed synthesis of 1,4-DHP^a.

Entry	Catalyst	Temperature (°C)/Ultrasonic Probe(W)	Solvent	Time (min)	Yieldb (%)	Ref.
1	γ-Fe2O3, MW, and fixed bed flow reactor	100	Solvent free	5	93.5	69
2	γ-Fe2O3@HAp@Melamine	80	Solvent free	15	94	70
3	Fe3O4/SiO2-PDA NPs/USW	Room temperature	EtOH	10	89	71
4	AIL-SCMNPs	60	Solvent free	10	92	72
5	Ultrasound Fe3O4@SiO2–SnCl4	40	EtOH	5	98	73
6	Fe3O4@SiO2@ADMPT/HPA nano catalyst	70	EtOH	35	92	74
7	NiFe2O4@SiO2–H14NaP5W30O110	120	Solvent free	10	94	75
8	Nano ZnFe2O4	Room temperature	H2O	30	90–96	76
9	(a) Hal-Fe3O4 with 1,3-ketoesters	Reflux	EtOH	20	96	77
	(b) Hal-Fe3O4 with dimedone	Reflux	EtOH	20	94
10	Fe3O4@IG	Ultrasound	EtOH	50	88	78
11	(a) γ-Fe2O3@Cu@cellulose for 1,4-dihydropyridine derivatives	Room temperature	Solvent free	Completion of reaction	80–92	79
	(b) γ-Fe2O3@Cu@cellulose for polyhydroquinoline derivatives	Room temperature	Solvent free	20	87–95
12	Nano-FGT	100–120	Solvent free	35	80–91	87
13	Fe–C–O–Mo alloy	Reflux	EtOH	150	92	88
14	Chitosan NPs	80	Solvent free	20	90	89
15	Fe3O4@chitosan	Room temperature	EtOH	30–140	84–98	90
16	MGCS	Reflux	EtOH	15	84–89	91

^aReaction conditions: aldehyde (1.0 mmol), ethyl acetoacetate (2.0 mmol), NH₄OAc (1–1.5 mmol), dimedone (2.0 mmol).

^bIsolated yields.