Functional Groups, A Short List Oxygen-containing Diketene Acetal/ketal Acid anhydride Ester Acyl halide Ether X = Cl, Br, I Ethylenedioxy- (crown ether) Acylal Hemiacetal/Hemiketal Alcohol Homoallylic Carbonate Hydroperoxide Carboxylic acid/carboxylate anion Ketene Chloroformate ester Ketone/aldehyde Dicarbonate Lactone 1 Methylenedioxy- Amide Orthocarbonate ester Amidine Orthoester Amidrazone Peroxide Amine Ynol* *Highly unstable, tautomer of ketene Azide Ynone Azine Nitrogen-containing Azo group Acylurea Azoxy Aldimine (primary/secondary) Carbamate 2 Carbazide Hydroxamic acid Carbodiimide Imide Carboximidate Imidic acid Cyanate Isocyanate Cyanimide Isonitrile Diazo group Ketenimine Enamide Ketimine (primary/secondary) Enamine Lactam Hydrazone Nitrile (cyanide) Nitrite 3 Nitrosamine Dithiocarboxylic acid ester Nitroso Isothiocyanate Oxime S-nitrosothiol Sulfate Semicarbazide Sulfenamide Semicarbazone Sulfenyl chloride Triazene Sulfinic acid Sulfur-containing Sulfite Disulfide Sulfonate ester Dithiocarbamate Sulfone Dithiocarboxylic acid 4 Sulfonic acid Thioketene Sulfonyl Thiol X = Cl, Br, I Thiolester Sulfoxide Thionoester Sulfuryl Thiosemicarbazide X = Cl, Br, I Thial Thiourea Thiocarboxylic acid (O) Phosphorus-containing Thiocarboxylic acid (S) Phosphate Thiocyanate Phosphine Thioether (sulfide) Phosphodiester Thioketone 5 Phosphonate Siloxy group Silyl chloride Phosphonic acid Silyl ether Phosphonite Silyl hydride Phosphoramide Phosphoramidite Alkyl groups Adamantyl group Silicon-containing Silanol Allyl group Benzyl group (–Bn) Silene Butyl group Silole s-Butyl group 6 Isobutyl group Boron-containing Borinic acid t-Butyl group Borinic ester Crotyl group (cis/trans) Boronic acid Ethyl group Boronic ester Isoprene Propyl group Miscellaneous Acetoxy (–OAc) Isopropyl group Acetyl group (–Ac) Neopentyl group Phenyl group (–Ph) Acryloyl group Propargyl group Acyl group Vinyl group 7 Benzoyl group (–Bz) Telluroketone* Tellurol* Enediyne *Tellurium-containing functional groups are highly unstable Tosyl group (–Ts) Nonaflate group Tosylate (–OTs) Selenenic acid Seleninic acid Triflate group (–Tf) Selenol Vanillyl group Selenonic acid Selone Functional groups featuring tautomerism Tautomerization of some of the functional groups found in the notes Tellurocyanate* Keto-enol tautomerization Telluroester* 8 Imine-enamine tautomerization Azetidine Oxetane Amide-imidic acid tautomerization Lactam-lactim tautomerization Oxolane / Tetrahydrofuran Pyrrolidine / Azolidine Nitroso-oxime tautomerization Tetrahydrothiophene Ketene-ynol tautomerization Oxole / Furan Heterocycles Epoxide (oxirane) Azole / Pyrrole Aziridine Thiophene Episulfide / Thiirane Imidazole Dioxirane Pyrazole 9 Pyridine Isoxazole Pyrimidine Oxazole Pyridazine Thiazole Pyrazine Triazole (1,2,3 and 1,2,4) Pyran Tetrahydropyran 4H-Pyran Piperidine / azinane Tetrahydrothiopyran Morpholine Dioxane 10 .