Table 2 Optimization for the Z-selective transfer semihydrogenation of 1aa

From: Modulation of metal species as control point for Ni-catalyzed stereodivergent semihydrogenation of alkynes with water

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Entry

Ligand

Base

T/oC

Yield/%c

2a/3ac

1

L1

CH3CO2K

80

87

70/30

2

L1

CH3CO2Cs

80

97

72/28

3

L1

HCO2Na

80

85

56/44

4

L1

PhCO2Na

80

93

80/20

5

L2

PhCO2Na

80

22

-

6

L3

PhCO2Na

80

83

93/7

7

L4

PhCO2Na

80

90

90/10

8

L5

PhCO2Na

80

83

91/9

9b

L3

PhCO2Na

80

90d

94/6

10b,e

L3

PhCO2Na

80

90d

94/6

11f

L3

PhCO2Na

60

59

94/6

12

L3

PhCO2Na

100

91

90/10

13

L3

PhCO2Na

120

87

86/14

  1. aReactions were performed with 1a (0.15 mmol), NiBr2 (10 mol%), L (22 mol%), base (2.0 equiv.), B2Pin2 (3.0 equiv.), H2O (3.0 equiv.), DMF (2 mL), 80 °C, 12 h.
  2. b5 mol% of NiBr2, 11 mol% of L3.
  3. cDetermined by crude 1H NMR.
  4. dIsolated yield.
  5. e1.0 equiv. of PhCO2Na.
  6. fThe conversion of 1a was 68% after 15 h.
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