Organocatalytic Visible Light Enabled SNAr of Heterocyclic Thiols: A Metal-Free Approach to 2-Aminobenzoxazoles and 4-Aminoquinazolines
The direct amination reaction of heterocyclic thiols has been developed in the presence of the nonhazardous photocatalyst Rose Bengal under irradiation of visible light. The reaction provides a straightforward approach to pharmaceutically and synthetically useful 2-aminobenzoxazole and 4-aminoquinazoline derivatives from the corresponding heterocyclic thiols with amines in good to excellent yields. Our photochemical reaction can be successfully adapted into a continuous flow reactor which is applicable for large-scale chemical industry. The key benefits of this reaction include the use of metal-free, low-cost Rose Bengal catalyst and practical operation (ambient temperature, open flask, and undried solvents).
Ozonation of thioamide containing heterocycles. A new general and selective procedure for the synthesis of C-2 substituted heteroazole derivatives
2-Mercaptoheteroazoles readily react with ozone in the presence of nucleophiles and under mild experimental conditions to form several C-2 substituted heterazoles.
OXIDATION OF 2-MERCAPTOBENZOHETERAZOLES BY DIMETHYLDIOXIRANE. A NEW METHOD FOR A SYNTHESIS OF C-2 SUBSTITUTED BENZIMIDAZOLE, BENZOXAZOLE, AND BENZOTHIAZOLE DERIVATIVES
New and efficient reactions in which 2-mercaptobenzoheterazoles are selectively converted by dimethyldioxirane, under mild experimental conditions, to several C-2 substituted benzoimidazole, benzoxazole, and benzothiazole derivatives are reported.
Electrooxidation of thiols in the presence of halide ions - A facile preparative method for synthesis of disulfides
The aliphatic, aromatic and heteroaromatic disulfides were easily synthesized by the electrolysis of corresponding thiols. The electrochemical method is also convenient for synthesis of unsymmetrically substituted disulfides and 'paired' synthesis of disu