Study On The Sulfation And Sulfonylation Of N-containing Heterocyclics

Sulfur-containing heterocyclic arenes are a class of important molecules with special physiological activity, which has been widely used in the area of materials and medicine. A number of synthetic methods have been developed for the synthesis of sulfur-containing heterocycle. A variety of thiolating agents has been developed to the direct thiolation of N-heterocyclic drug skeletons. Presently, reagents used for thiolation and sulfonylation mainly include: disulfides,thioalcohol, sulfinate, and sulfonyl chloride. However, these thiolation methods are insufficient for the diversity synthesis of sulfur-containing compounds. To explore an efficient thiolation method with good functional groups tolerance, the development of a simple, operational simplicity and inexpensive thiolating agent is highly desirable. This paper includes four parts:(1) The methods for the thiolation of N-heterocycles have been reviewed. Thiolating agents including thiol, sulfide, sulfinate, sulf-onyl chloride, sulfonyl hydrazide, and elemental sulfur et al. were discussed,respectively. Additionally, the methods for the synthesis of sulfonamides were also reviewed.(2) A metal-free method for the thiolation of imidazoheterocycles using elemental sulfur as the thiolating agent has been developed. The three component thiolation reaction of imidazoheterocycles, halo alkanes, and elemental sulfur proceeded smoothly in the presence of organic base. A variety of haloalkanes are suitable for this transformation with moderate to good yields.(3) An iodine-mediated tandem C-H thiolation and amination of pyridine disulfide with N-methyl aromatic amines for the synthesis of benzopyridothiazines has been developed. This protocol do not require high temperature, noble metal catalysis, and ligand. In the presence of iodine and FeF3, a variety of benzopyridothiazines are prepared in moderate to good yields.(4) A Cu(OAc)2/I2-mediated direct sulfonylation of benzo[d]imidazoles with disulfides has been studied. A variety of diaryl disulfides underwent the sulfonylation with benzimidazole successfully to afford sulfonamides in moderate to excellent yields. The isotopic labeling experiments indicate that the oxygen atoms in the sulfonyl derived from water.