Table 1. Optimization Studiesa.
| entry | amine 2 (equiv) | Ca(NTf2)2 (equiv) | base (equiv) | solvent (conc, M) | temp (°C) | time (h) | yield (%) |
|---|---|---|---|---|---|---|---|
| 1 | 2 | 1 | t-amylOH (0.2) | 60 | 24 | 70 | |
| 2 | 2 | 1 | t-amylOH (0.2) | 90 | 24 | 89 | |
| 3 | 2 | 1.1 | t-amylOH (0.2) | 100 | 24 | 92 | |
| 4 | 2 | 1.1 | t-amylOH (1.0) | 90 | 2 | 96 | |
| 5 | 1.05 | 1.1 | t-amylOH (1.0) | 90 | 2 | 52 | |
| 6 | 1.05 | 1.1 | DIPEA (1.5) | t-amylOH (1.0) | 90 | 2 | 95 (54)b |
| 7 | 1.05 | 1.1 | DABCO (1.5) | t-amylOH (1.0) | 90 | 2 | 96 (88)b |
| 8 | 1.05 | 1.1 | DABCO (1.5) | THF (0.5) | rt | 24 | 93 |
| 9 | 1.05 | 0 | DABCO (1.5) | THF (0.5) | rt | 24 | NRc |
a
Reaction scale: sulfamoyl fluoride 1 (0.35 mmol, 1.0 equiv).
b
Reaction was performed in the presence of 5% water by volume.
c
No reaction.