Table 2.
Tautomeric Transform Classification
| Rule number | Rule name |
|---|---|
| Existing CACTVS rules (Prototropic tautomerism) | |
| PT_02_00 | 1,5 (thio)keto/(thio)enol |
| PT_03_00 | simple (aliphatic) imine |
| PT_04_00 | special imine |
| PT_05_00 | 1,3 aromatic heteroatom H-shift |
| PT_06_00 | 1,3 heteroatom H-shift |
| PT_07_00 | 1,5 (aromatic) heteroatom H-shift (1) |
| PT_08_00 | 1,5 (aromatic) heteroatom H-shift (2) |
| PT_09_00 | 1,7 (aromatic) heteroatom H-shift |
| PT_10_00 | 1,9 (aromatic) heteroatom H-shift |
| PT_11_00 | 1,11 (aromatic) heteroatom H-shift |
| PT_12_00 | 1,3 furanones |
| PT_13_00 | keten-inol exchange |
| PT_14_00 | ionic nitro/aci-nitro |
| PT_15_00 | pentavalent nitro/aci-nitro |
| PT_16_00 | nitroso/oxime |
| PT_17_00 | oxime/nitroso via phenol |
| PT_18_00 | cyanic/iso-cyanic acids |
| PT_19_00 | formamidinesulfonic acid |
| PT_20_00 | isocyanide |
| PT_21_00 | phosphonic acid |
| New rules (Prototropic tautomerism) | |
| PT_11_01 | 1,13 (aromatic) heteroatom H-shift |
| PT_11_02 | 1,15 (aromatic) heteroatom H-shift |
| PT_11_03 | 1,17 (aromatic) heteroatom H-shift |
| PT_11_04 | 1,19 (aromatic) heteroatom H-shift |
| PT_22_00 | imine/imine |
| PT_23_00 | 1,5 furanones |
| PT_24_00 | 1,4 N-oxide/N-hydroxide |
| PT_25_00 | 1,6 N-oxide/N-hydroxide (1) |
| PT_26_00 | 1,6 N-oxide/N-hydroxide (2) |
| PT_27_00 | acene |
| PT_27_01 | thiophene analogue of acene |
| PT_28_00 | nitro/aci-nitro via aromatic ring (1) |
| PT_29_00 | nitro/aci-nitro via aromatic ring (2) |
| PT_29_01 | o-tolualdehyde |
| PT_30_00 | nitramide/N-nitronic acid |
| PT_31_00 | sulfone-based aliphatic compounds |
| PT_32_00 | nitrile/ketenimine 1,3 H-shift |
| PT_33_00 | nitrile/ketenimine 1,5 H-shift |
| PT_34_00 | triad phosphorus-carbon |
| PT_35_00 | sulfenyl/sulfinyl |
| PT_36_00 | oxime/nitrone |
| PT_37_00 | sulfenyl/S-oxide |
| PT_38_00 | sila-hemiaminal/silanoic amide |
| PT_39_00 | nitrone/azoxy or Behrend rearrangement |
| PT_40_00 | tetrad phosphorus-carbon |
| PT_41_00 | pyridine 1-oxide/1-hydroxypyridine |
| PT_42_00 | Δ3- /Δ4-pyrro(thio/seleno)lin-2-one |
| PT_43_00 | phthalan/isobenzofuran |
| PT_44_00 | 2-subsituted-pyrrole |
| PT_45_00 | isoindole/isoindolenine |
| PT_46_00 | 4-picoline |
| PT_47_00 | isopropylidenecycloalkane/isopropylcycloalkene |
| PT_48_00 | benzofuranone |
| PT_49_00 | N-hydroxyindole |
| Existing rules 17 (Ring–chain tautomerism) | |
| RC_03_00 | 5_exo_trig |
| RC_04_01 | 6_exo_trig |
| RC_04_02 | 6_exo_trig |
| RC_09_00 | 5_endo_trig |
| RC_10_00 | 6_endo_trig |
| New rules (Ring–chain tautomerism) | |
| RC_03_03 | boronic acid/oxaborole |
| RC_03_04 | 5_exo_trig |
| RC_04_04 | 6_exo_trig |
| RC_12_00 | 5_endo_tet or iminophosphorane/benzoxazaphospholine |
| RC_13_00 | 6_endo_dig |
| RC_14_00 | thiadiazoline rearrangement |
| RC_15_00 | 5_exo_trig |
| RC_16_00 | boryl/borate |
| RC_17_00 | boryl/borate |
| RC_18_00 | 5_exo_tet or hydroxyphosphorane |
| RC_19_00 | nitroolefin/1,2-oxazine N-oxide |
| RC_20_00 | 5_endo_trig |
| RC_21_00 | cyclobutane/enamine |
| RC_22_00 | 5_endo_trig |
| RC_23_00 | 6_endo_trig |
| RC_24_00 | λ5-/λ3-phosphane |
| New rules (Valence tautomerism) | |
| VT_01_00 | monothio-o-benzoquinone/benzoxathiete |
| VT_01_01 | α-dithione and 1,2-dithiete |
| VT_02_00 | tetrazole/azide |
| VT_03_00 | isothiocyanate/triazinethione |
| VT_04_00 | tetrazine/azodiazo |
| VT_05_00 | 1,2,3-triazole/diazoamidine |
| VT_06_00 | norcaradiene/cycloheptatriene or benzene-oxide/oxepin |
| VT_07_00 | phospha-münchnones |
| VT_08_00 | 1,2,3,4-tetrazinium/azodiazonium |
| VT_09_00 | phosphinoimine/diazaphosphazole |
| VT_10_00 | phosphine/phosphonium salt |