Table 1 Comparison of Ni-H and Co-H catalyzed enantioselective anti-Markovnikov hydroalkylation of alkenesa

From: Enantioselective synthesis of chiral α,α-dialkyl indoles and related azoles by cobalt-catalyzed hydroalkylation and regioselectivity switch

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Entry

Metal salt

Solvent

Yield (%)

er

1

NiBr2·DME

DME

9

69:31

2

NiBr2·DME

THF

trace

N.D.

3

NiBr2·DME

DMA

trace

N.D.

4

NiBr2·DME

DMF

trace

N.D.

5

CoBr2·DME

DME

98

95:5

6

CoBr2·DME

THF

75

95:5

7

CoBr2·DME

DMA

48

57:43

  1. a 1a (0.10 mmol), 2a (0.20 mmol, 2.0 equiv), metal salt (10 mol%), L6 (15 mol%), CsF (0.20 mmol, 2.0 equiv), DEMS (0.20 mmol, 2.0 equiv), solvent (0.5 mL, 0.2 M), 0 °C, 24 h. Isolated yields. Er value was determined by chiral HPLC analysis. DEMS = diethoxymethylsilane.
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