Table 1 Reaction condition optimization

From: Electricity-driven asymmetric bromocyclization enabled by chiral phosphate anion phase-transfer catalysis

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Entry

Deviation from standard condition

Yield, e.e.

1

None

99%, 95% e.e.

2

Without (R)-CPA1

30%, −

3

Without PTC1

66%, 25% e.e.

4

Without NaHCO3

27%, 89% e.e.

5

Na2CO3 instead of NaHCO3

17%, −

6

KBr instead of NaBr

>95%, 93% e.e.

7

NaCl or NaI instead of NaBr

no reaction

8

Glassy carbon as anode

30%, 75% e.e.

9

Nickel foam as cathode

45%, 73% e.e.

10

EtOAc instead of toluene

90%, 20% e.e.

  1. Detailed reaction parameters for the optimized conditions and the reaction outcomes upon changing the parameters. Reaction scale: 1a (0.1 mmol), (R)-CPA1 (5 mol %), PTC1 (10 mol %), NaHCO3 (0.1 M in H2O), NaBr (1.0 M in H2O), toluene (2 mL), H2O (2.5 mL), Pt anode and cathode (10 mm × 10 mm × 0.2 mm), stirring speed: 1000 r/min, 2 mA, rt, 4 h. Boc tert-butyloxylcarbonyl. The yields were determined by crude 1H NMR analysis, and e.e. values were determined by chiral HPLC.
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