. 2021 Apr 7;6(15):10415–10427. doi: 10.1021/acsomega.1c00868

Table 1. Optimization of Reaction Parameters in the Iridium Complex-Catalyzed Transfer Hydrogenation of N-Heteroarenes^a.

entry	catalyst	hydrogen donor	solvent	yield/%^b
1	TC-1	HCO₂H	H₂O	65
2	TC-2	HCO₂H	H₂O	60
3	TC-3	HCO₂H	H₂O	54
4	TC-4	HCO₂H	H₂O	58
5	TC-5	HCO₂H	H₂O	52
6	TC-6	HCO₂H	H₂O	53
7	TC-1	HCO₂Na	H₂O	39
8^c	TC-1	HCO₂H/Et₃N	H₂O	44
9^d	TC-1	HCO₂H/HCOONa	H₂O	45
10	TC-1	HCO₂H	DMSO	<5
11	TC-1	HCO₂H	toluene	24
12	TC-1	HCO₂H	THF	<5
13	TC-1	HCO₂H	CH₂Cl₂	17
14	TC-1	HCO₂H	MeCN	21
15	TC-1	HCO₂H	MeOH	53
16^e	TC-1	HCO₂H	H₂O	73
17^f	TC-1	HCO₂H	H₂O/MeOH	95(92)

Reaction conditions: 1a (0.25 mmol), solvent (2.0 mL), catalyst (1.0 mol %), and hydrogen donor (5.0 equiv) at room temperature under air for 12 h.

Determined by GC–MS using dodecane as the internal standard. The number in the parentheses is the isolated yield.

The reaction was carried out with 5.0 equiv of HCO₂H and 2.0 equiv of Et₃N.

The reaction was carried out with 5.0 equiv of HCOOH and 2.0 equiv of HCOONa.

The reaction was carried out at 80 °C.

H₂O/MeOH = 1:1.

Table 1. Optimization of Reaction Parameters in the Iridium Complex-Catalyzed Transfer Hydrogenation of N-Heteroarenesa.