Sulfur heterocycles, literature

Thionyl chloride (SOCl2) is the most versatile of all sulfur transfer reagents in heterocyclic synthesis. The sulfur-oxygen bond renders the sulfur atom more electrophilic the possibility of ready removal by elimination of the oxygen atom allows easy aromatization of many of the initially formed sulfur heterocycles. Two general reviews of the chemistry of thionyl chloride are available.53 Both cover the literature up to about 1970. 

There are a few reports in the literature in which the carbonyl group has been formally replaced by another unsaturated function. Thio-benzophenone (268) undergoes photochemical 1,2-cycloaddition to a-phellandrene (269) to give the thietane (270), together with the sulfur heterocycles (271 and 272) formed by 1,4-cycloaddition.298 Isoprene, cyclopentadiene, and 1,4-diphenylbutadiene also undergo 1,4-cycloaddition with thiobenzophenone, but 1,3-cyclooctadiene... 

The thiopyranofurans contain a six-membered sulfur heterocyclic ring and a five-membered oxygen heterocyclic ring (Table 10). Another common name for these isomers is furothiopyrans. Not much chemical literature exists regarding the thiopyranofuran compounds. 

A limited number of accounts of the literature have appeared Brandsma [36], Kwart [5], Paquer [37], Anisimov [38], our contribution in the context of thiocarbonyl compounds in synthesis [39] and a recent review by Majumdar [40] with an emphasis on the synthesis of sulfur heterocycles. 

Early literature - claimed that the three isomeric cresols, on heating with a large excess of chlorosulfonic acid, afforded condensation products termed sulfonylides which probably possess the structures 130-132 containing an interesting eight-membered oxygen-sulfur heterocyclic ring. For example, o-... 

For the identification of sulfur heterocycles the measurement of mass spectra is employed (64, 65), and the quoted literature also contains information on the measurement of infrared spectra. 

This review is divided into sections depending on the quantity of sulfur atoms in the formed heterocycle. We have examined all the literature data for the last 150 years up to March 2007, including the latest achievements concerning 1,2,3-dithiazoles fused with other heterocycles. We do not discuss the Herz reaction since it is well known and has been reviewed (1957CRV1011). 

Of the possible four-membered sulfur-containing heterocyclic rings that contain another heteroatom, which is not sulfur, oxygen, or nitrogen, only the thiaphosphetanes, silathietanes, and selenathietanes are discussed in the literature up to 1980. 

The literature contains examples of virtually all heterocyclic systems with two heteroatoms of nitrogen, sulfur and oxygen. However, in some cases simple derivatives of the parent... 

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