Table 1 Optimization of the reaction conditionsa

From: Organocatalyzed diastereo- and enantioselective synthesis of N–N atropisomeric isoindolinones bearing central chirality

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Entry

Catalyst

Solvent

Yield (%)b

ee (%)c

drd

1

(R)-A1

Toluene

33

−25

10:1

2

(R)-A2

Toluene

23

−7

17:1

3

(R)-A3

Toluene

54

−26

12:1

4

(S)-A4

Toluene

53

91

13:1

5

(R)-B1

Toluene

56

−22

12:1

6

(R)-B2

Toluene

60

−9

10:1

7

(R)-B3

Toluene

42

−40

15:1

8

(R)-C1

Toluene

trace

ND

ND

9

(R)-C2

Toluene

trace

ND

ND

10

(S)-A4

DCE

63

28

8:1

11

(S)-A4

o-Xylene

50

89

10:1

12

(S)-A4

PhCl

51

89

10:1

13e

(S)-A4

Toluene

65

92

>20:1

14e, f

(S)-A4

Toluene

73

93

>20:1

15e, g

(S)-A4

Toluene

61

91

>20:1

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  1. aReaction conditions: 1a (0.1 mmol), 2a (0.05 mmol), catalyst (10 mol%), toluene (0.5 mL).
  2. bIsolated yields are provided.
  3. cThe ee values were determined by chiral HPLC.
  4. dDiastereomeric ratios (dr) were determined from 1H NMR of the isolated product.
  5. eReaction performed at −20 °C.
  6. f5 mol% of (S)-A4 was used.
  7. g2.5 mol% of (S)-A4 was used. DCE, 1,2-dichloroethane; PhCl, chlorobenzene.
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