In this review, we try to underscore the applications of intermolecular and intramolecular FC reactions in the total syntheses of natural products and complex molecules, exhibiting diverse biological properties.

in Wiley Online Library (wileyonlinelibrary.com).An efficient, facile, and useful synthetic method was developed for the production of spiro[indoline-3,4 0pyrano-pyrazole] carbonitrile derivatives through a one-pot, four-component reaction involving hydrazine hydrate, diketene, substituted isatins, and malononitrile or ethyl cyanoacetate in the presence of iodine as the efficient catalyst in ethanol at room temperature. Significantly, this remarkable method provides novel spiropyranopyrazole derivatives in good to high yields. The significant aspects of this protocol are facile work-up approach and a greener process because the use of toxic and hazardous solvents are avoided. 6 0 -Amino-5-chloro-3 0 -methyl-2-oxo-1 0 H-spiro[indoline-3,4 0pyrano[2,3-c]pyrazole]-5 0 -carbonitrile (2e).White powder, mp = 295-294°C, 0.28 g, yield: 85%. IR (KBr) (ν max , cm À1 ): 3386 and 3347 (NH 2 ), 3137 (2NH), 2182 (CN), December 2018One-Pot Four-Component Synthesis of Spiro[indoline-3,4 0 -pyrano-pyrazole] Derivatives 2777