Table 1 Optimization of the reaction conditionsa,b.

From: Bioinspired desaturation of alcohols enabled by photoredox proton-coupled electron transfer and cobalt dual catalysis

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Entry

Change from standard conditions

Yield [%] (2a/2a’)

1

No change

93 (22:1)

2c

PC-II as photocatalyst

0 (-)

3c

PC-III as photocatalyst

1 (-)

4c

PC-IV as photocatalyst

71 (25:1)

5

K3PO4 as base

2 (-)

6

2,6-lutidine as base

86 (20:1)

7

Co(dmgH)(dmgH2)Cl2 as cobalt source

60 (6:1)

8

Co(dmgH)2PyCl as cobalt source

88 (24:1)

9

HFIP as solvent

0 (-)

10

MeCN as solvent

6 (-)

11

Toluene as solvent

42 (19:1)

12

DCM as solvent

92 (19:1)

13

No light or [Co] or collidine or PC-I

0 (-)

  1. aReaction conditions: 1a (0.1 mmol, 1 equiv.), 2,4,6-collidine (0.2 mmol, 2 equiv.), PC-I (7.5 mol%), Co(dmgH)2(py) 2PF6 (10 mol%), DCE (1.0 mL, 0.1 M), rt, blue LEDs, 36 h.
  2. bYields and ratios were determined by 1H NMR of the crude mixture using 1,3,5-trimethoxybenzene as an internal standard.
  3. c1 mol% photocatalyst was used.
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