Table 1 Condition optimization.

From: Transient-axial-chirality controlled asymmetric rhodium-carbene C(sp2)-H functionalization for the synthesis of chiral fluorenes

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Entrya

Rh(II)

Solvent

Yield (%)b

Ee (%)c

1

Rh2(S-TCPTTL)4

DCM

91

60

2

Rh2(S-TCPTTL)4

DCE

90

63

3

Rh2(S-TCPTTL)4

Toluene

85

75

4

Rh2(S-TCPTTL)4

Hexane

90

62

5

Rh2(S-TCPTTL)4

TBME

92

82

6d

Rh2(S-TCPTTL)4

TBME

80

81

7d

Rh2(S-PTTL)4

TBME

82

15

8

Rh2(S-NTTL)4

TBME

90

65

9

Rh2(S-TBPTTL)4

TBME

92

70

10

Rh2(S-TFPTTL)4

TBME

90

99

11

Rh2(S-PTPA)4

TBME

75

5

12

Rh2(S-PTA)4

TBME

72

2

13

Rh2(S-DOSP)4

TBME

90

13

14d

Rh2(S-PTAD)4

TBME

92

25

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  1. DCM dichloromethane, DCE 1,2-dichloroethane, TBME tert-butyl methyl ether.
  2. aThe reaction was carried out on a 0.2 mmol scale: 1a (0.2 mmol), and 4 Å MS (100 mg) in 1.0 mL solvent, was added a solution the catalyst in 1.0 mL of the same solvent via syringe pump in 40 min under inert atmosphere.
  3. bIsolated yields.
  4. cDetermined by chiral HPLC analysis, see SI for details.
  5. dThe reaction was conducted at 0 °C for 24 h.
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