Table 1 Reaction condition optimization.

From: Synthesis of difluoromethylated allenes through trifunctionalization of 1,3-enynes

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Entry

Cat.

Ligand

Solvent

Yield of 4a (%)a

1

CuTC

1,10-Phen

DCM

<5

2

Pd(OAc)2

BC

DCM

34

3

PdCl2

1,10-Phen

DCM

24

4

CoCl2

1,10-Phen

DCM

trace

5

Pt(COD)Cl2

1,10-Phen

DCM

40

6

NiCl2

1,10-Phen

DCM

48

7

–

–

DCM

28b

8

–

–

DCM

44c

9

–

–

toluene

66c (65)d, e

10

–

–

CHCl3

61c

11

–

–

CH3CN

12c

12

–

–

toluene

51f

  1. Reaction conditions: 1,3-enyne (1a, 0.25 mmol), NFSI (0.75 mmol), cat (10 mol%), ligand (10 mol%), solvent (0.5 mL), 65 oC, under a N2 atmosphere
  2. 1,10-Phen 1,10-phenanthroline, BC bathocuproine
  3. a1H NMR yield
  4. bThe reaction was performed at 60 oC
  5. cThe reaction was performed at 80 oC
  6. dIsolated yield in parentheses
  7. eThe 1H NMR yield of 3a is 8%
  8. fThe reaction was performed at 100 oC
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