Organosulfur chemistry is the study of the properties and synthesis of organosulfur compounds, which are organic compounds that contain sulfur. They are often associated with foul odors, but many of the sweetest compounds known are organosulfur derivatives, e.g., saccharin. Nature abounds with organosulfur compounds—sulfur is vital for life. Of the 20 common amino acids, two (cysteine and methionine) are organosulfur compounds, and the antibiotics penicillin and sulfa drugs both contain sulfur. While sulfur-containing antibiotics save many lives, sulfur mustard is a deadly chemical warfare agent. Fossil fuels, coal, petroleum, and natural gas, which are derived from ancient organisms, necessarily contain organosulfur compounds, the removal of which is a major focus of oil refineries.
Sulfur shares the chalcogen group with oxygen, selenium, and tellurium, and it is expected that organosulfur compounds have similarities with carbon–oxygen, carbon–selenium, and carbon–tellurium compounds.
A classical chemical test for the detection of sulfur compounds is the Carius halogen method.
Organosulfur compounds can be classified according to the sulfur-containing functional groups, which are listed (approximately) in decreasing order of their occurrence.
Image:R-allicin-2D-skeletal.svg|[[Allicin]], the active flavor compound in crushed garlic
Image:Cysteine.svg| (''R'')-[[Cysteine]], an [[amino acid]] containing a thiol group
Image:Methionin - Methionine.svg|[[Methionine]], an [[amino acid]] containing a sulfide
Image:Diphenyl disulfide.svg|[[Diphenyl disulfide]], a representative disulfide
Image:Dibenzothiophen - Dibenzothiophene.svg|[[Dibenzothiophene]], a component of crude oil
Image:Perfluorooctanesulfonic acid structure.svg|[[Perfluorooctanesulfonic acid]], a controversial surfactant
Image:Lipoic_acid.svg|[[Lipoic acid]], an essential cofactor of four mitochondrial enzyme complexes.
Image:Penicillin core.svg|[[Penicillin]] core structure, where "R" is the variable group.
image:Sulfanilamide-skeletal.
