Synthesis of Spiropyrazoles Under Organic and Nonorganic Catalysis

Spiropyrazoles display many biological activities such as antitumor, vasodilation, analgesic, phosphodiesterase inhibitors, aldosterone antagonistic, anabolic, androgenic, anti-inflammatory, progestational and salt-retaining activities, and they also exert neuroprotection in dopaminergic cell death. Many efforts have been made to obtain these derivatives with high yield and excellent regio-, diastereo- and enantioselectivities. Most of the spiroprazole synthesis methods were proceeded in good to excellent yield in the presence of organic catalysts, such as squaramide, NHC pre-catalyst, pyrrole derivatives, bis-oxazoline, etc. DMAP, DABCO, thiourea derivatives, DBU, acetic acid and quinoline catalysts. In addition, the inorganic and organometallic catalysts have been proven their efficiency in the synthesis of various types of spiro-pyrazoles in excellent yield. Thus, in this review, we have compiled all citations for the synthesis of spiropyrazoles in the presence of various types of catalysts such as organic, inorganic, and metalorganic catalysts in the range 2020 to 2012. This review article is a useful compilation for researchers interested in the synthesis of spiropyrazole derivatives and will assist them in selecting appropriate catalysts for the preparation of their spiropyrazoles.