Table 1. Aromatic and aliphatic thiol pKa values and corresponding yields in N–O bond cleavage assays.
| Entry | Thiol | pKa14,29 | Yield (%) |
|---|---|---|---|
| 1 | 4-Nitrothiophenol | 4.5 | 59 |
| 2 | 3-Mercaptobenzoic acid | 5.8 | 81 |
| 3 | 4-Mercaptophenylacetic acid | 6.6 | 73 |
| 4 | 4-Aminothiophenol | 6.9 | 73 |
| 5 | 4-Hydroxythiophenol | 7.0 | n.d. |
| 6 | 2,2,2-Trifluoroethanethiol | 7.6 | n.d. |
| 7 | L-Glutathione | 9.1 | n.d. |
| 8 | D,L-Dithiothreitol | 9.2, 10.1 | n.d. |
| 9 | 2-Mercaptoethanesulfonic acid | 9.2 | n.d. |
| 10 | 2-Methyl-2-propanethiol | 11.2 | n.d. |
n.d.=no detectable N–O bond cleavage.