Entry

ArCHO (R)

Catalyst

Solvent

Additives

Temp (˚C)

Time (h)

Product (Y%)^b

ee (%)^c

1

12a (4-NO₂)

1

–

–

25

48

13a (29)

20

2

12a (4-NO₂)

2

–

–

25

12

13a (54)

78

3

12a (4-NO₂)

3

–

–

25

36

13a (47)

3

4

12a (4-NO₂)

2

DMF

–

25

24

–

–

5

12a (4-NO₂)

2

DMSO

–

25

24

–

–

6

12a (4-NO₂)

2

toluene

–

25

12

13a (46)

44

7

12a (4-NO₂)

2

CHCl₃

–

25

12

13a (49)

44

8

12a (4-NO₂)

2

–

AcOH

25

5

13a (80)

65

9

12a (4-NO₂)

2

–

TfOH

25

48

13a (30)

60

10

12a (4-NO₂)

2

–

H₂O

25

15

13a (87)

70

11

12a (4-NO₂)

2

–

H₂O

5

24

13a (87)

81

12

12a (4-NO₂)

2

–

–

-20

48

13a (85)

87

13

12a (4-NO₂)

2^d

–

–

25

20

13a (51)

75

14

12a (4-NO₂)

2^d

–

–

5

24

13a (88)

77

15

12a (4-NO₂)

2^d

–

–

-20

52

13a (50)

88

16

12a (4-NO₂)

4

–

–

25

35

13a (72)

95

17

12a (4-NO₂)

4

–

–

5

48

13a (46)

95

18

12a (4-NO₂)

4^d

–

–

25

48

13a (51)

96

19

12a (4-NO₂)

4^d

–

–

5

51

13a (38)

95

20

12b (2-NO₂)

4

–

–

25

30

13b (58)

95

21

12c (4-Br)

4

–

–

25

30

13c (70)

88

22

12d (4-Cl)

4

–

–

25

30

13d (61)

85

23

12e (H)

4

–

–

25

30

13e (61)

90

24

12f (naphthyl)

4

–

–

25

30

13f (68)

81

25

12g (5-Cl,2-NO₂)

4

–

–

25

30

13g (72)

92

26

12h (2,4-2MeO)

4

–

–

25

30

13h (29)

72

27

12a (4-NO₂)

5

–

–

25

48

13a (68)

31