An efficient and practical protocol for the geminal heterodihalogenation of methyl ketones by using readily available dimethyl sulfoxide and a combination of HCl and HBr is reported. Control experiments suggested that the acidity of the solution, as well as the oxidizing ability and nucleophilicity of the dimethyl sulfoxide might work cooperatively in ensuring the success of the tandem substitution. Its operational simplicity, easy accessibility, and mild oxidative conditions suggest that the present strategy might be useful for the assembly of bromochloromethyl functional groups in drug discovery.
β-Nitrostyrenes underwent the Diels-Alder reaction with Danishefsky’s diene to afford cyclohexenes together with the corresponding hydrolyzed products, 3-arylated 5-methoxy-4-nitrocyclohexanones. When the reaction was conducted in the presence of water, the cyclohexenes were efficiently hydrolyzed into cyclohexanones. Subsequent aromatization by heating the cyclohexanone with a catalytic amount of iodine in dimethyl sulfoxide gave 3-arylated 4-nitrophenols. The reaction of nitrostyrenes with Danishefsky’s diene could be conducted in one-pot to directly afford the corresponding nitrophenols. Moreover, a heteroaryl group such as a thienyl group could be introduced into the nitrophenol framework.
β-Nitrostyrenes underwent a Diels–Alder reaction with Danishefsky’s diene to afford cyclohexenes together with the corresponding hydrolyzed products, 3-arylated-5-methoxy-4-nitrocyclohexanones. When the reaction was conducted in the presence of water, the cyclohexenes were efficiently hydrolyzed into cyclohexanones. Subsequent aromatization by heating the cyclohexanone with a catalytic amount of iodine in dimethyl sulfoxide gave 3-arylated-4-nitrophenols. The reaction of nitrostyrenes with Danishefsky’s diene could be conducted in one pot to directly afford the corresponding nitrophenols. Moreover, a heteroaryl group, e.g., a thienyl group could be introduced into the nitrophenol framework.
In this study, cyanations or azidations of imines were performed by using hydroxy(dimethyl)-λ4-sulfanecarbonitrile or azido(dimethyl)-λ4-sulfanol, respectively, prepared in situ by treatment of potassium cyanide or sodium azide with a dimethyl sulfoxide–nitric acid combination. Furthermore, a one-pot preparation of 5-substituted 1H-tetrazole derivatives was carried out by using this reagent combination in the presence of an aldehyde, hydroxylamine hydrochloride, and sodium azide under mild conditions.
Ammonium persulfate–dimethyl sulfoxide (APS–DMSO) has been developed as an efficient and new dehydrating reagent for a convenient one-pot process for the synthesis of miscellaneous cyclic imides in high yields starting from readily available primary amines and cyclic anhydrides. A plausible radical mechanism involving DMSO has been proposed. The application of this facile one-pot imide forming process has been demonstrated for a practical synthesis of vernakalant.
One-Pot and Metal-Free Synthesis of 3-Arylated 4-Nitrophenols via Polyfunctionalized Cyclohexanones from β-Nitrostyrenes