Table 1 Optimization of N–H insertion of NH3·H2O with diazo compound

From: Chemoselective carbene insertion into the N−H bonds of NH3·H2O

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Entry

Cat.

Solvent

T (°C)

2 Yielda

3 Yieldb

1

TpBr3Ag(thf) (10 mol %)

DCE

60

92%

<5%

2

TpBr3Ag(thf) (10 mol %)

DCM

60

57%

<5%

3

TpBr3Ag(thf) (10 mol %)

THF

60

N.D.

N.D.

4

TpBr3Ag(thf) (10 mol %)

1,4-Dioxane

60

N.D.

N.D.

5

TpBr3Ag(thf) (10 mol %)

Toluene

60

23%

N.D.

6

TpBr3Ag(thf) (10 mol %)

CHCl3

60

75%

<5%

7

Tp(CF3)2Ag(thf) (10 mol %)

CHCl3

60

40%

N.D.

8

AgOAc (10 mol %)

CHCl3

60

N.D.

N.D.

9

Fe(TPP)Cl (10 mol %)

CHCl3

60

N.D.

N.D.

10

Rh2(OAc)4 (5 mol %)

CHCl3

60

N.D.

N.D.

11

Cu(OAc)2 (10 mol %)

CHCl3

60

N.D.

N.D.

12

Pd(OAc)2 (10 mol %)

CHCl3

60

Trace

N.D.

13

TpBr3Ag(thf) (10 mol %)

DCE

80

75%

N.D.

  1. Reaction conditions: methyl phenyldiazoacetate 1 (0.3 mmol), NH3·H2O (2.4 mmol, 8.0 equiv) and Cat. (5–10 mol %) in solvent (4.0 mL) was stirred at 60 °C under nitrogen atmosphere for 12 h.
  2. N.D. not detected, DCE 1,2-dichlorethane, DCM dichloromethane, TPP tetraphenylporphyrin.
  3. aIsolated yield.
  4. bYield was determined by 1H NMR with dibromomethane as the internal standard.
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