Table 1. Hydrogenation of 4-Fluorobenzaldehyde with Several Manganese and Rhenium Catalysts^a.

entry	cat.	solvent	S/C	P (bar)	t (h)	conversion (%)b	TON
1	Mn1	THF	1000	50	18
2	Mn1	toluene	1000	50	18
3	Mn1	EtOH	1000	30	1	54	540
4	Mn1	EtOH	1000	30	4	>99	1000
5	Mn1	EtOH	2000	50	18	>99	2000
6c	Mn1	EtOH	20000	50	48	52	10400
7	Mn2	EtOH	100	50	18
8	Mn3	EtOH	100	50	18	21	21
9	Re1	EtOH	100	50	18	86	86
10d	Re1	EtOH	100	50	18	95	95
11	Re2	EtOH	100	50	18	76	76

^aReaction conditions: catalysts (0.4–20.0 μmol), 4-fluorobenzaldehyde (2.0 mmol), EtOH (4 mL), 50 bar H₂, 25 °C.

^bDetermined by ¹⁹F NMR spectroscopy.

^cIn the presence of DBU (1.2 μmol, 3 equiv).

^dPerformed at 50 °C.