Table 1 Optimization of the reaction conditionsa

From: Mechanistic study on the side arm effect in a palladium/Xu-Phos-catalyzed enantioselective alkoxyalkenylation of γ-hydroxyalkenes

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Entry

Additive

[Pd]

Base

Solvent

Yield%

Ee%

1

H2O

[Pd(allyl)Cl]2

NaOtBu

Et2O/Hexane = 1:1

74

92

2

--

[Pd(allyl)Cl]2

NaOtBu

Et2O/Hexane = 1:1

84

84

3

4 Å MS

[Pd(allyl)Cl]2

NaOtBu

Et2O/Hexane = 1:1

79

91

4

MeOH

[Pd(allyl)Cl]2

NaOtBu

Et2O/Hexane = 1:1

75

79

5

EtOH

[Pd(allyl)Cl]2

NaOtBu

Et2O/Hexane = 1:1

54

70

6

iPrOH

[Pd(allyl)Cl]2

NaOtBu

Et2O/Hexane = 1:1

52

60

7

H2O

Pd(dba)2

NaOtBu

Et2O/Hexane = 1:1

43

93

8

H2O

Pd(OAc)2

NaOtBu

Et2O/Hexane = 1:1

72

92

9

H2O

PdCl2

NaOtBu

Et2O/Hexane = 1:1

12

78

10

H2O

[Pd(allyl)Cl]2

KOtBu

Et2O/Hexane = 1:1

11

H2O

[Pd(allyl)Cl]2

LiOtBu

Et2O/Hexane = 1:1

41

7

12

H2O

[Pd(allyl)Cl]2

Cs2CO3

Et2O/Hexane = 1:1

15

85

13

H2O

[Pd(allyl)Cl]2

NaOH

Et2O/Hexane = 1:1

29

97

14

H2O

[Pd(allyl)Cl]2

NaOtBu

Toluene

90

91

15

H2O

[Pd(allyl)Cl]2

NaOtBu

THF

51

90

16

H2O

[Pd(allyl)Cl]2

NaOtBu

Et2O

36

94

17

H2O

[Pd(allyl)Cl]2

NaOtBu

Hexane

55

88

  1. aReaction conditions: 1a (0.1 mmol), 2a (0.2 mmol), NaOtBu (4 equiv.), H2O (2 equiv.), [Pd(allyl)Cl]2 (2.5 mol%), Xu8 (10 mol%) in 1 mL Et2O/Hexane under N2 at RT for 72 h. Isolated yields. ee was determined by chiral HPLC analysis.