Synthesis of New Spirooxindole-Fused Isoxazoline/Triazole and Isoxazoline/Isoxazole Derivatives from Three-Component 1,3-Dipolar Cycloaddition

A series of diverse heterocycles containing spirooxindole, isoxazoline/triazole, and isoxazole rings has been synthesized via an efficient three-component reaction of (E)-2-(1-propargyl-2-oxoindoline-3-ylidene) acetophenones 1, arylnitrile oxides 2, and arylazides 3 using Cu(I) as catalyst. The regiochemistry and stereochemistry of cycloadducts 4a and 5a have been confirmed by X-ray diffraction studies. The heterocycles were screened against Gram-positive and Gram-negative bacteria and fungi. Several compounds exhibit moderate to excellent activities comparable to those of established standard drugs.