Table 3 Optimization of the 3-catalyzed asymmetric A3-coupling reactiona

From: Photothermal conversion triggered thermal asymmetric catalysis within metal nanoparticles loaded homochiral covalent organic framework

View full size image

Entry

Cat.

Solvent

T (°C)/hv

Yield (ee) %b

1

3 (2.1 mol Pd %)

p-dioxane

r.t./hv

98 (96)

2

3 (2.1 mol Pd %)

Toluene

r.t./hv

81 (89)

3

3 (2.1 mol Pd %)

EtOH

r.t./hv

58 (92)

4

3 (2.1 mol Pd %)

CH3CN

r.t./hv

70 (96)

5

3 (2.8 mol Pd %)

p-dioxane

r.t./hv

98 (96)

6

3 (1.4 mol Pd %)

p-dioxane

r.t./hv

90 (97)

7

3 (2.1 mol Pd %)

p-dioxane

45 °C/dark

90 (96)

8

3 (2.1 mol Pd %)

p-dioxane

r.t./dark

21 (90)

9

1 (1.0 mol %)

p-dioxane

r.t./hv

55 (92)

10

1 (1.0 mol %)

p-dioxane

45 °C/dark

50 (87)

11

Cu-TBrPP

p-dioxane

r.t./hv

46 (−)

12

Pd NPs (5.0 mol %)

p-dioxane

r.t./hv

17 (−)

13

Pd NPs (5.0 mol %)

p-dioxane

45 °C/dark

67 (−)

14

3 (2.1 mol Pd %)

p-dioxane

r.t./sunlight

45 (92)

15

Pd@amorphous polymer (2.1 mol% Pd %)

p-dioxane

r.t./hv

78 (14)

  1. aReaction conditions: 3 (6.0 mg, 2.8 mol Pd% equiv; 4.5 mg, 2.1 mol Pd% equiv; 3.0 mg, 1.4 mol Pd% equiv), benzaldehyde (0.5 mmol), phenylacetylene (0.5 mmol) and pyrrolidine (0.75 mmol), solvent (2 mL), 300 W xenon with a power density of 2.5 W cm−2 (λ > 400 nm), in nitrogen, 10 h
  2. bYield was determined by the GC on HP-5 column, and ee was determined by HPLC with a Chiralcel OJ-H column (99: 1 = n-hexane: isopropanol, 1.0 mL min−1, 254 nm) (Supplementary Figs. 21 and 22). The comparison of 3 with reported asymmetric A3-coupling reaction was shown in Supplementary Table 5. 3 herein met excellent yield and stereoselectivity, mild reaction conditions and multiple reuse
Back to article page