Transfer hydrogenation of aldehydes using 3, 4, 6 or 7 as catalyst^a.

Entry	Substrate	Catalyst	Isolated yield (%)
1		7	98
		6	94
		3	70
		4	73
2		7	91
		6	83
		3	66
		4	74
3		7	89
		6	85
		3	72
		4	70
4		7	82
		6	83
		3	70
		4	71
5		7	79
		6	82
		3	73
		4	70
6		7	85
		6	84
		3	68
		4	72
7		7	84
		6	80
		3	73
		4	71
8		7	80
		6	81
		3	71
		4	66
9		7	75
		6	77
		3	65
		4	61
10		7	81
		6	83
		3	70
		4	66
11		7	80
		6	81
		3	64
		4	61
12		7	87
		6	84
		3	73
		4	76
13		7	95
		6	91
		3	77
		4	71
14		7	77
		6	75
		3	77
		4	75
15		7	82
		6	79
		3	61
		4	67
16b		7	75
		6	71
		3	61
		4	66
17		7	80
		6	76
		3	60
		4	69
18		7	77
		6	74
		3	58
		4	63
19		7	70
		6	72
		3	55
		4	61
20		7	0
		6	0
		3	0
		4	0
21		7	0
		6	0
		3	0
		4	0
22		7	0
		6	0
		3	0
		4	0

^aSubstrate (1.0 mmol), KO^tBu (0.02 mmol), catalyst (0.02 mmol), ⁱPrOH (5 mL), 60 °C, 24 h.

^bThe reduced product is 3-phenylpro-2-yn-1-ol because the elimination occurred during the work-up.