Table 1 Optimization of the reaction conditionsa

From: Iron-catalyzed three-component amino(radio)fluorination of alkenes to unprotected β-(radio)fluoroamines

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Entry

[Fe]

Fluorine source

[NH2] source

Solvent

Yield of 2ab

1

FePc

TMAF

I

CH3CN

N.D.

2

FePc

AgF

I

CH3CN

N.D.

3

FePc

HF·Py

I

CH3CN

trace

4

FePc

Et3N·3HF

I

CH3CN

23%

5

Fe(OTf)2

Et3N·3HF

I

CH3CN

N.D.

6

FeSO4

Et3N·3HF

I

CH3CN

N.D.

7

Fe(acac)2

Et3N·3HF

I

CH3CN

N.D.

8c

FeSO4 + bipyridine

Et3N·3HF

I

CH3CN

N.D.

9c

FeSO4 + terpyridine

Et3N·3HF

I

CH3CN

N.D.

10

FePc

Et3N·3HF

I

THF

5%

11

FePc

Et3N·3HF

I

HFIP

N.D.

12

FePc

Et3N·3HF

I

DCM

54%

13

FePc

Et3N·3HF

I

CHCl3

50%

14d

FePc

Et3N·3HF

I

DCM

60%

15e

FePc

Et3N·3HF

I

DCM

45%

16d

FePc

Et3N·3HF (2.0 eq)

I

DCM

43%

17d

FePc

Et3N·3HF (8.0 eq)

I

DCM

61%

18d

FePc

Et3N·3HF

II–V

DCM

see in the graph

19d,f

FePc

Et3N·3HF

V

DCM

71% (73%)h

20d,f,g

FePc

Et3N·3HF

V

DCM

68%

21d,f

Pc

Et3N·3HF

V

DCM

N.D.

  1. aReaction conditions: hydroxylamine reagent (I ~ V) (0.75 mmol) was added into a mixture of alkene 1a (0.30 mmol), [Fe] (0.03 mmol), and [F] (1.2 mmol) in DCM (2.0 mL) at 40 °C, and the reaction was allowed to proceed under N2 for 30 min
  2. bYield of isolated product after Boc protection
  3. cAddition of external ligand (0.03 mmol)
  4. dAt 30 °C
  5. eAt 50 °C
  6. fOpen to air
  7. gFor 3 h
  8. hIsolated yield without Boc protection
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