Screening of the reaction conditions for the synthesis of 3a^a.

Entry	Reductant (mmol)	Cat. (mg)	Solvent	Base	Time (h)	Yieldb (%)
1	NaBH4 (1)	50	EtOH	Pyridine	2	Trace
2	NaBH4 (1)	50	CH3CN	Pyridine	2	45
3	NaBH4 (1)	50	Ethyl acetate	Pyridine	2	15
4	NaBH4 (1)	50	H2O	Pyridine	2	Trace
5	NaBH4 (1)	50	DMF	Pyridine	2	7
6	NaBH4 (1)	50	CH2Cl2	Pyridine	2	55
7	NaBH4 (1)	50	C2H4Cl2	Pyridine	2	78
8	NaBH4 (1)	50	H2O : C2H4Cl2	Pyridine	0.5	92
9	NaBH4 (1)	40	H2O : C2H4Cl2	Pyridine	0.5	88
10	NaBH4 (1)	20	H2O : C2H4Cl2	Pyridine	1	60
11	NaBH4 (1)	10	H2O : C2H4Cl2	Pyridine	1	40
12	NaBH4 (1)	60	H2O : C2H4Cl2	Pyridine	0.5	92
13	NaBH4 (1)	50	H2O : C2H4Cl2	Et3N	2	41
14	NaBH4 (1)	50	H2O : C2H4Cl2	K2CO3	2	56
15	NaBH4 (1)	50	H2O : C2H4Cl2	Na2CO3	2	50
16	NaBH4 (1)	50	H2O : C2H4Cl2	KOH	2	70
17	NaBH4 (1)	50	H2O : C2H4Cl2	NaHCO3	2	60
18	NaBH4 (1)	50	H2O : C2H4Cl2	—	24	40
19	NaBH4 (1)	50	H2O : C2H4Cl2	Pyridine	0.5	88c
20	NaBH4 (2)	50	H2O : C2H4Cl2	Pyridine	0.5	92
21	NaBH4 (0.5)	50	H2O : C2H4Cl2	Pyridine	2	60
22	NaBH4 (1)	50	H2O : C2H4Cl2	Pyridine	12	Traced
23	NaBH4 (1)	50	H2O : C2H4Cl2	Pyridine	12	50e
24	NaBH4 (1)	40	H2O : C2H4Cl2	Pyridine	12	39f
25	NaBH4 (1)	70	H2O : C2H4Cl2	Pyridine	12	59g
26	NaBH4 (1)	100	H2O : C2H4Cl2	Pyridine	12	72h

^aReaction conditions: nitroarene (0.5 mmol), LDH@MPS-GMA-TZ-CuI (5 mg), 1,3-disulfonylchloride (0.25 mmol), pyridine (0.5 mmol), NaBH₄ (1.0 mmol) and H₂O : C₂H₄Cl₂ (1 : 1, 2 mL), at room temperature.

^bIsolated yield.

^cThe reaction was investigated at 50 °C.

^dThe reaction was investigated in the presence of Cu–Zn–Al LDH.

^eThe reaction was investigated in the presence of CuI NPs (50 mg).

^fThe reaction was investigated in the presence of CuI NPs (40 mg).

^gThe reaction was investigated in the presence of CuI NPs (70 mg).

^hThe reaction was investigated in the presence of CuI NPs (100 mg).