In the presence of cesium carbonate, an efficient synthesis of aryl methyl sulfides by the reactions of aryl halides with commercially available S-methylisothiourea sulfate is developed. This odourless and highly crystalline solid can be used as the substitute for malodorous methanethiol. The gram-scale reaction also proceeds smoothly without the use of column chromatography separation. Similarly, 2-(dimethylamino)ethylthio and cyclopropylmethylthio groups can be easily introduced into the aromatic rings from the corresponding S-[2-(dimethylamino)ethyl]isothiourea dihydrochloride and S-cyclopropylmethylisothiourea hydrobromide. The possible reaction mechanism is proposed. It is believed that this route to aryl alkyl sulfides is well competitive with currently known methods due to its wide substrate scope, excellent yields, easy operation and transition-metal-free conditions.

The low loading combination of the complex [9,9‐dimethyl‐4,5‐bis(diphenylphosphino)xanthene] (Xantphos)copper(I) iodide and simple ligand‐free palladium(II) acetate was found to be efficient for the domino synthesis of diarylalkynes by the reaction of aryl halides with trimethylsilylethynylene or bis(trimethylsilyl)acetylene in a single‐step procedure. The unsymmetrical diarylalkynes can be obtained through a one‐pot two‐step approach. The reactions of aryl bromides with 1,4‐bis(trimethylsilyl)butadiyne also furnished the corresponding 1,4‐diaryl‐1,3‐diynes in a similar fashion. This route to diarylalkynes and 1,4‐diaryl‐1,3‐diynes is complementary to previously reported synthetic procedures.magnified image

The transition metal‐free cross‐coupling reactions of cyanopyrimidines with aliphatic alcohols, thiols (or S‐alkylisothiourea salts) and amines, giving the corresponding alkoxylpyrimidines, aminopyrimidines, and alkylthiopyrimidines, are reported. Preliminary mechanistic studies reveal that it probably involves a sequential nucleophilic addition‐intramolecular rearrangement process, which is promoted by an intramolecular N–H···N five‐membered hydrogen bonding interaction. The presence of a nitrogen atom next to the cyano group is indispensable. The wide substrate scope with excellent yields makes cyanopyrimidines a promising alternative substrate class to the frequently used pyrimidines halides for the formation of C–O, C–S, and C–N bonds through the decyanative cross‐coupling reaction.