Table 1 Preliminary exploration of reaction conditionsa

From: Phosphinothio(seleno)ation of alkynes/olefins and application on the late-stage functionalization of natural products

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Entry

Lewis acid

Base

Solvent

Temp.

Time

Isolated Yield (%)

1

BF3·OEt2 (1.0 eq.)

Et3N

toluene

90 °C

4 h

91

2

BF3·OEt2 (1.0 eq.)

/

toluene

90 °C

4 h

0

3

BF3·OEt2 (1.0 eq.)

Et3N

CH3CN

90 °C

4 h

78

4

BF3·OEt2 (1.0 eq.)

Et3N

1,4-dioxane

90 °C

4 h

43

5

BF3·OEt2 (1.0 eq.)

Et3N

ethyl acetate

90 °C

4 h

47

6

BF3·OEt2 (1.0 eq.)

Et3N

DMF

90 °C

4 h

0

7

BF3·OEt2 (1.0 eq.)

Et3N

toluene

110 °C

4 h

Trace

8

BF3·OEt2 (1.0 eq.)

Et3N

toluene

50 °C

4 h

23

9

BF3·OEt2 (1.0 eq.)

K2CO3

toluene

90 °C

4 h

26

10

BF3·OEt2 (1.0 eq.)

DIPEA

toluene

90 °C

4 h

Trace

11

BF3·OEt2 (1.0 eq.)

KOH

toluene

90 °C

4 h

22

12

BF3·2MeOH (1.0 eq.)

Et3N

toluene

90 °C

4 h

Trace

13

BF3·2AcOH (1.0 eq.)

Et3N

toluene

90 °C

4 h

0

14

BF3·OEt2 (0.5 eq.)

Et3N

toluene

90 °C

4 h

0

15

BF3·OEt2 (2.0 eq.)

Et3N

toluene

90 °C

4 h

Trace

16

BF3·OEt2 (1.0 eq.)

Et3N

toluene

90 °C

2 h

27

17

BF3·OEt2 (1.0 eq.)

Et3N

toluene

90 °C

6 h

82

  1. aReaction condition: 1a (0.36 mmol), S8 (0.30 mmol), 2a (0.30 mmol), Lewis acids, Base (0.30 mmol), Solvent (2 mL).
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