Table 1 Optimization of reaction

From: One pot conversion of phenols and anilines to aldehydes and ketones exploiting α gem boryl carbanions

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Entry

Gem-B(pin)

Tempr

Oxidant (equiv)

Yield (%)

1a

1

−78 oC

H2O2/NaOH (3)

18

2a

1

−78 oC to rt

H2O2/NaOH (3)

40

3a

1

0 oC

H2O2/NaOH (3)

52

4b

1

0 oC

H2O2/NaOH (3)

68

5c

1

0 oC

H2O2/NaOH (3)

59

6d

1

0 oC

H2O2/NaOH (3)

74

7e

1

0 oC

H2O2/NaOH (3)

10

8f

1

0 oC

H2O2/NaOH (3)

58

9

1

0 oC to rt

H2O2/NaOH (3)

60

10

1.5

0 oC

H2O2/NaOH (3)

80

11

2.0

0 oC

H2O2/NaOH (3)

76

12g

1.5

0 oC

H2O2/NaOH (3)

72

13

1.5

0 oC

NaBO3 4H2O (3)

90

14

1.5

0 oC

Et3NO (3)

52

15h

1.5

0 oC

NaBO3 4H2O (5)

78

  1. 1 equiv of 4-Methoxyphenol was taken. Dry THF used 1 mL/1 mmol of quinketal. Yields are isolated and calculated from the phenol. aNaOMe, bK2CO3, cNaHCO3, dNa2CO3, eEt3N used to quench AcOH. fReaction carried out for 10 min. gOxidation time maintained 30 min. H2O2/NaOH were premixed at 0 oC before addition. Solid NaBO3 4H2O was added followed by equal volume water (w.r.t THF) added. hReaction was carried out also with 1 equiv oxidant but result in 56% yield.
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