Sulfinyl halide have the general formula R−S(O)−X, where X is a halogen. They are intermediate in oxidation level between

sulfenyl halide In organosulfur chemistry, a sulfenyl chloride is a functional group with the connectivity , where R is alkyl or aryl. Sulfenyl chlorides are reactive compounds that behave as sources of . They are used in the formation of and bonds. According ...

s, R−S−X, and

sulfonyl halide In chemistry, a sulfonyl halide consists of a sulfonyl () group singly bonded to a halogen atom. They have the general formula , where X is a halogen. The stability of sulfonyl halides decreases in the order fluorides > chlorides > bromides > iod ...

s, R−SO₂−X. The best known examples are sulfinyl chlorides, thermolabile, moisture-sensitive compounds, which are useful intermediates for preparation of other sufinyl derivatives such as sulfinamides,

sulfinate Sulfinic acids are oxoacids of sulfur with the structure RSO(OH). In these organosulfur compounds, sulfur is Molecular geometry, pyramidal. Structure and properties Sulfinic acids RSO2H are typically more acidic than the corresponding carboxyl ...

sulfoxide In organic chemistry, a sulfoxide, also called a sulphoxide, is an organosulfur compound containing a sulfinyl () functional group attached to two carbon atoms. It is a polar functional group. Sulfoxides are oxidized derivatives of sulfides. E ...

s, and

thiosulfinate In organosulfur chemistry, thiosulfinate is a functional group consisting of the linkage (R refers to organic substituents). Thiolsulfinates are also named as alkanethiosulfinic (or arenethiosulfinic) acid esters. They are the first of the seri ...

s. Unlike the sulfur atom in

s and

s, the sulfur atom in sulfinyl halides is

chiral Chirality () is a property of asymmetry important in several branches of science. The word ''chirality'' is derived from the Greek language, Greek (''kheir''), "hand", a familiar chiral object. An object or a system is ''chiral'' if it is dist ...

, as shown for methanesulfinyl chloride.

Sulfinyl chlorides

Sulfinic acid chlorides, or sulfinyl chlorides, are sulfinyl halides with the general formula R−S(O)−Cl. Methanesulfinyl chloride, CH₃S(O)Cl, is prepared by chlorination of

dimethyl disulfide Dimethyl disulfide (DMDS) is an organic chemical compound with the molecular formula . It is a flammable liquid with an unpleasant, garlic-like odor resembling that of "leaking gas". The compound is colorless, although impure samples often appea ...

to give CH₃SCl₃, which is treated with

acetic anhydride Acetic anhydride, or ethanoic anhydride, is the chemical compound with the chemical formula, formula . Commonly abbreviated , it is one the simplest organic acid anhydride, anhydrides of a carboxylic acid and is widely used in the production of c ...

. It is a straw-colored liquid. Toluenesulfinyl chloride is prepared by treating sodium tosylate with

thionyl chloride Thionyl chloride is an inorganic compound with the chemical formula . It is a moderately Volatility (chemistry), volatile, colourless liquid with an unpleasant acrid odour. Thionyl chloride is primarily used as a Halogenation, chlorinating reagen ...

: Also a straw-colored liquid, it boils near 100 °C at 0.5 mm Hg. A general approach to the formation of sulfinyl chlorides is by reaction of the corresponding

thiol In organic chemistry, a thiol (; ), or thiol derivative, is any organosulfur compound of the form , where R represents an alkyl or other organic substituent. The functional group itself is referred to as either a thiol group or a sulfhydryl grou ...

with

sulfuryl chloride Sulfuryl chloride is an inorganic compound with the formula SO2Cl2. At room temperature, it is a colorless liquid with a pungent odor. Sulfuryl chloride is not found in nature. Sulfuryl chloride is commonly confused with thionyl chloride, SOC ...

, ; in cases where the

sulfenyl chloride In organosulfur chemistry, a sulfenyl chloride is a functional group with the connectivity , where R is alkyl or aryl. Sulfenyl chlorides are reactive compounds that behave as sources of . They are used in the formation of and bonds. According ...

, RSCl, results instead, a trifluoroperacetic acid oxidation affords the desired product, as in the case of 2,2,2-trifluoro-1,1-diphenyl

ethanethiol Ethanethiol, commonly known as ethyl mercaptan, is an organosulfur compound with the formula CH3CH2SH. It is a colorless liquid with a distinct odor. Abbreviated EtSH, it consists of an ethyl group (Et), CH3CH2, attached to a thiol group, SH. It ...

Reactions

These compounds react readily with nucleophiles like water, alcohols, amines, thiols, and Grignard reagents. If the nucleophile is water the product is a

sulfinic acid Sulfinic acids are oxoacids of sulfur with the structure RSO(OH). In these organosulfur compounds, sulfur is pyramidal. Structure and properties Sulfinic acids RSO2H are typically more acidic than the corresponding carboxylic acid RCO2H. Su ...

, if it is an alcohol the product is a sulfinic ester, if it is a primary or secondary amine the product is a sulfinamide, if it is a thiol the product is a

, while if it is a Grignard reagent the product is a

. Because of their reactivity and instability, alkanesulfinyl chlorides are generally used without purification immediately after their synthesis. Storage is not recommended since pressure develops within the container due to hydrogen chloride release. Treatment of alkanesulfinyl chlorides having α-hydrogens with tertiary amine bases gives thiocarbonyl ''S''-oxides (sulfines) as isolable compounds. Thus, treatment of ''n''-propanesulfinyl chloride with

triethylamine Triethylamine is the chemical compound with the formula N(CH2CH3)3, commonly abbreviated Et3N. Like triethanolamine and the tetraethylammonium ion, it is often abbreviated TEA. It is a colourless volatile liquid with a strong fishy odor remini ...

gives ''syn''-propanethial-''S''-oxide, the lachrymatory agent of the

onion An onion (''Allium cepa'' , from Latin ), also known as the bulb onion or common onion, is a vegetable that is the most widely cultivated species of the genus '' Allium''. The shallot is a botanical variety of the onion which was classifie ...

. Treatment of methanesulfinyl chloride or ethane-1,2-bis-sulfinyl chloride, (prepared by oxidative chlorination of 1,2-ethanedithiol, HSCH₂CH₂SH), with a tertiary amine in the presence of the chiral

glucose Glucose is a sugar with the Chemical formula#Molecular formula, molecular formula , which is often abbreviated as Glc. It is overall the most abundant monosaccharide, a subcategory of carbohydrates. It is mainly made by plants and most algae d ...

-derived secondary alcohol diacetone-D-glucose affords optically pure sulfinate esters by a process of Dynamic kinetic resolution. Sulfinyl chlorides undergo Friedel–Crafts reactions with arenes giving

Sulfinyl fluorides, bromides, and iodides

Room temperature hydrolysis of CF₃SF₃ gives the sulfinyl fluoride CF₃S(O)F in a few hours in quantitative yield. Treatment of CF₃S(O)F with

hydrogen bromide Hydrogen bromide is the inorganic compound with the formula . It is a hydrogen halide consisting of hydrogen and bromine. A colorless gas, it dissolves in water, forming hydrobromic acid, which is saturated at 68.85% HBr by weight at room temper ...

at −78 °C gives the sulfinyl bromide CF₃S(O)Br, which is unstable at room temperature and readily disproportionates. Sulfinyl iodides are apparently unknown compounds.

References

{{reflist Halides Organosulfur compounds