No abstract

An efficient palladium-catalyzed protocol for the synthesis of 4-bromoisoxazoles derivatives in moderate to good yields from readily available O-methyl oximes in basic ionic liquid has been developed. Their structures were confirmed by 1 H NMR, 13 C NMR and HRMS. This cascade cyclization/bromination process provides a novel route for directly accessing 4-bromoisoxazole in good to excellent yields and good functional group tolerance with high atom efficiency. Notably, the current methodology could also be conveniently applied to the synthesis of isoxazoles naturally occurring biologically active frameworks.

An efficient and practical N-iodosuccinimide-promoted regioselective arylsulfenylation of imidazo[1,2-a]pyridines with disulfides has been developed to afford functionalized 3-sulfenylimidazo[1,2-a]pyridines heterocycles in moderate to good yields. Their structures were confirmed by IR, 1 H NMR, 13 C NMR and HRMS. Furthermore, this method has the advantages of mild reaction conditions, broad substrates scope and environmentally benign. Notably, the current methodology could also be conveniently applied to the synthesis of thioarylated naturally occurring biologically active frameworks.

A Pd-catalyzed method was developed for cross-coupling reaction of a wide range of haloalkynes with hex-5-en-1-ol in ionic liquids. In the presence of PdBr 2 , [Bmim]X and HX aq , the cross-coupling products can be obtained in moderate to good yields, and the reaction displayed high regio-and stereo-selectivities. Moreover, the reaction is a convenient and simple path for the synthesis of the cis-1,2-dihalosubstituted alkenes, and tolerates several functional groups on haloalkynes.